2021/10/28 更新

写真a

キワ トシヒコ
紀和 利彦
KIWA Toshihiko
所属
ヘルスシステム統合科学学域 教授
職名
教授
連絡先
メールアドレス

研究キーワード

  • terahertz technology

  • femtosecond laser

  • super conductor

  • SQUID

  • テラヘルツ波工学

  • フェムト秒レーザー

  • 超伝導

  • 磁気ナノ粒子

  • 磁気抗体検査

  • 全固体電池

研究分野

  • ライフサイエンス / 医用システム

  • ナノテク・材料 / 光工学、光量子科学

  • ものづくり技術(機械・電気電子・化学工学) / 電子デバイス、電子機器

経歴

  • 岡山大学   大学院ヘルスシステム統合科学研究科   教授

    2020年4月 - 現在

      詳細を見る

  • 岡山大学   大学院ヘルスシステム統合科学研究科   准教授

    2018年4月 - 2020年3月

      詳細を見る

  • - 岡山大学自然科学研究科 准教授

    2004年 - 2018年3月

      詳細を見る

  • - Associate Professor,Graduate School of Natural Science and Technology,Okayama University

    2004年

      詳細を見る

所属学協会

委員歴

  • 応用物理学会 テラヘルツ電磁波技術研究会   委員長  

    2012年3月 - 2017年3月   

      詳細を見る

    団体区分:学協会

    researchmap

  • 電気学会   中国支部役員  

    2009年 - 2010年   

      詳細を見る

    団体区分:学協会

    電気学会

    researchmap

  • 応用物理学会   委員・応用物理分野のアカデミックロードマップテラヘルツエレクトロニクスクラスター  

    2009年 - 2010年   

      詳細を見る

    団体区分:学協会

    応用物理学会

    researchmap

  • 応用物理学会   シンポジウムオーガナイザー・テラヘルツ光科学の新展開  

    2009年   

      詳細を見る

    団体区分:学協会

    応用物理学会

    researchmap

  • 応用物理学会   テラヘルツ電磁波技術研究会 代表幹事  

    2009年   

      詳細を見る

    団体区分:学協会

    応用物理学会

    researchmap

 

論文

  • Noninvasive, label-free, and quantitative monitoring of lipase kinetics using terahertz emission technology

    Sharifun Nahar, Ahmed Mohamed, Xavier Ropagnol, Amir Hassanpour, Toshihiko Kiwa, Tsuneyuki Ozaki, Marc A. Gauthier

    BIOTECHNOLOGY AND BIOENGINEERING   2021年7月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:WILEY  

    Enzymes catalyze chemical transformations of great importance in many fields, and analysis of the rate of these transformations is equally important. The latter are typically monitored using surrogate substrates that produce quantifiable optical signals, owing to limitations associated with "label-free" techniques that could be used to monitor the transformation of original substrate molecules. In this study, terahertz (THz) emission technology is used as a noninvasive and label-free technique to monitor the kinetics of lipase-induced hydrolysis of several substrate molecules (including the complex substrate whole cow's milk) and horseradish peroxidase-catalyzed oxidation of o-phenylenediamine in the presence of H2O2. This technique was found to be quantitative, and kinetic parameters are compared to those obtained by proton NMR spectroscopy or UV/Vis spectroscopy. This study sets the stage for investigating THz emission technology as a tool for research and development involving enzymes, and for monitoring industrial processes in the food, cosmetic, detergent, pharmaceutical, and biodiesel sectors.

    DOI: 10.1002/bit.27893

    Web of Science

    researchmap

  • Properties of single- and multi-core magnetic nanoparticles assessed by magnetic susceptibility measurements

    Mohd Mawardi Saari, Mohd Herwan Sulaiman, Nurul Akmal Che Lah, Zulkifly Aziz, Kenji Sakai, Toshihiko Kiwa, Keiji Tsukada

    JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS   528   2021年6月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ELSEVIER  

    Characterization of structural and magnetic properties of MNP ensembles is crucial in tailoring their performance for biomedical applications. In this work, we evaluate the size distribution of magnetic cores in single- and multi-core nanoparticles in water suspension using transmission electron microscopy (TEM) and static magnetization curve, with the geometrical core size ranges from 8.3 to 40.2 nm. A reasonable core size derived from the magnetization curve is obtained in comparison to the geometrical size from TEM image. The magnetic moment distribution possibly reveals that the reduction of effective magnetic core size is due to the magnetization degradation in cores. The hydrodynamic size and average anisotropy energy ratio obtained from the AC susceptibility response of MNPs from 5 Hz to 100 kHz are also evaluated. The complex distribution of relaxation time is constructed by applying a non-negative least square method to an AC susceptibility model that incorporates the inter- and intra-potential-well contributions. It is found that a log-normal distribution might not be adequate to represent the hydrodynamic size distribution reconstructed from the AC susceptibility responses of the suspended samples. It is demonstrated that the AC susceptibility model used in this study can be used to fairly estimate the average anisotropy energy ratio for MNP ensembles dominated by thermally blocked particles. Moreover, it can be suggested that besides the geometrical core size, the degree of core aggregation also plays an important role in determining the anisotropy energy ratio and effective magnetic moment.

    DOI: 10.1016/j.jmmm.2021.167812

    Web of Science

    researchmap

  • Evaluation of penetration speed of liquids into skin using a terahertz time-of-flight method

    Sota Sueda, Tomoya Niki, Kenji Sakai, Toshihiko Kiwa

    JAPANESE JOURNAL OF APPLIED PHYSICS   60 ( 3 )   2021年3月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:IOP PUBLISHING LTD  

    Analyzing the penetration of cosmetic/medical lotions and creams into the skin is important for evaluating their effectiveness. Hence, the penetration speed of liquids into chicken and pig skins was evaluated using a terahertz (THz) time-of-flight method. An arsenide-free disposable THz emitter comprising a silicon film on a sapphire substrate was developed for practical measurements using skin samples. The skin sample was mounted on the THz emitter surface directly so that the generated THz pulses in the silicon film were easily focused on the skin sample. To evaluate the time evolution of the penetration depth, the arrival times of the reflected THz pulses at the edge of the liquid-penetrated region on the skin were observed. As a preliminary experiment, measurements using a stack of conventional glass slides were conducted. In addition, the penetration speed into the chicken and pig skin was compared to prove the practical applicability of our method.

    DOI: 10.35848/1347-4065/abdd03

    Web of Science

    researchmap

  • Terahertz imaging technique for monitoring the flow of buffer solutions at different pH values through a microfluidic chip

    Feroz Ahmed, Atsuya Mahana, Katsuya Taniizumi, Jin Wang, Kenji Sakai, Toshihiko Kiwa

    Japanese Journal of Applied Physics   60 ( 2 )   2021年2月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:IOP PUBLISHING LTD  

    © 2021 The Japan Society of Applied Physics Polydimethylsiloxane (PDMS)-based mold prepared using a 3D-printed structure is a cost-effective material and tool to fabricate robust microfluidic chips (MCs) without requiring expensive clean room facilities. A capillary-based MC made of PDMS can be attached onto a glass substrate to visualize the chemical reactions in different types of pH buffer solutions (BSs) flowing through microflow channels (MFCs) using terahertz (THz) image sensing technology. In this study, we designed a microfluidic structure with two inlet wells and an outlet well, equipped with a Si:sapphire substrate to visualize the chemical interaction between BSs injected at different pH values (4 and 10) through an MFC. THz imaging maps were captured during the flow of the BSs using a THz chemical microscope, and the fluid dynamics was studied. We determined and plotted the variation in the THz amplitude data with respect to the BS concentration and analyzed the characteristics of the data.

    DOI: 10.35848/1347-4065/abd86e

    Web of Science

    Scopus

    researchmap

  • Imaging of Defect Signal of Reinforcing Steel Bar at High Lift-Off Using a Magnetic Sensor Array by Unsaturated AC Magnetic Flux Leakage Testing

    Minoru Hayashi, Taisei Kawakami, Taisuke Saito, Kenji Sakai, Toshihiko Kiwa, Keiji Tsukada

    IEEE Transactions on Magnetics   57 ( 2 )   2021年2月

     詳細を見る

    掲載種別:研究論文(学術雑誌)  

    © 1965-2012 IEEE. Reinforcing steel bars (rebars) in the concrete need to be inspected to prevent the structure from collapsing. Magnetic nondestructive testing methods can inspect the rebar without the influence of concrete. However, since the inspection is performed at a high lift-off on concrete, a strong applied magnetic field is required in order to measure a sufficient magnetic signal generated from the rebar. In addition, if a single sensor is used to measure the rebar, this requires the scanning of extensive area along the invisible rebar covered with the concrete. To overcome these problems, we have developed a method to detect and image the defect signal using unsaturated ac magnetic flux leakage (USAC-MFL) testing combining a magnetic sensor array probe. The USAC-MFL is a method that uses an alternating magnetic field in the initial magnetization characteristics of steel, which does not require a strong applied magnetic field compared to the conventional MFL method. By measuring the magnetic flux from the rebar in a wide area using the magnetic sensor array probe, the defect signal was able to be detected and imaged. The defect signal was able to be confirmed up to the lift-off of 100 mm even when the defect was half length of the rebar or located on the back side.

    DOI: 10.1109/TMAG.2020.3017722

    Scopus

    researchmap

  • A sensitive magnetometer utilizing high-T <inf>c</inf> SQUID for magnetic property characterization

    Mohd Mawardi Saari, Kenji Sakai, Toshihiko Kiwa, Keiji Tsukada

    Microsystem Technologies   2021年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:SPRINGER HEIDELBERG  

    © 2021, The Author(s), under exclusive licence to Springer-Verlag GmbH, DE part of Springer Nature. Magnetometer is one of the indispensable instruments utilized for the magnetic property characterization of materials, where it evaluates the magnetic response originated from the materials. The non-invasive magnetic technique has promoted magnetometer to be utilized in new applications such as in biomedical applications. In this work, we report the development of a magnetometer utilizing a high critical temperature superconducting quantum interference device (high-Tc SQUID) and a flux transformer composed of an induction coil. The high-Tc SQUID is used in order to realize high sensitivity, compact, and low-running cost magnetometer for biomedical applications such as characterization of magnetic nanoparticles. A first-order planar gradiometer with a compensation coil was used as the detection coil to achieve high sensitivity and cancellation factor. We fabricate an electromagnet with primary and small secondary excitation coils to enable a wide range of the excitation magnetic field with a high resolution. To reduce the magnetic field’s drift, we apply a digital feedback program to control the electrical current of the electromagnet. The performance of the developed system is demonstrated by measuring the magnetization curve and AC responses of an iron oxide composite sample. The sensitivity showed by the developed magnetometer reveals its potential for a highly sensitive magnetic property characterization.

    DOI: 10.1007/s00542-020-05198-6

    Web of Science

    Scopus

    researchmap

  • Electric Potential Distribution on Lithium Ion Battery Cathodes Measured Using Terahertz Chemical Microscopy

    Toshihiko Kiwa, Yuki Akiwa, Hayato Fujita, Takashi Teranishi, Kenji Sakai, Hidetoshi Nose, Masaki Kobayashi, Keiji Tsukada

    Journal of Infrared, Millimeter, and Terahertz Waves   41 ( 4 )   430 - 437   2020年4月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:SPRINGER  

    © 2019, Springer Science+Business Media, LLC, part of Springer Nature. A terahertz chemical microscope has been developed to visualize electric potential distribution on lithium ion battery cathodes during battery operation. A sensing plate comprising a Si film grown epitaxially on a sapphire substrate was used as a terahertz emitter. The amplitude of terahertz radiation from the sensing plate could be related to the electric potential at the exact point where a femtosecond laser illuminated. Here, the sensing plate was integrated into a conventional can-type lithium ion battery and terahertz radiation from the sensing plate was observed during battery operation between 2.7 and 4.2 V. By scanning the laser, the distribution of terahertz amplitude radiated from the sensing plate was observed, which could be related to the electric potential distribution on the electrodes of the batteries. Localized electric potential could be visualized as the amplitude of terahertz radiation generated in the sensing plate, which was integrated beneath the battery electrode.

    DOI: 10.1007/s10762-019-00640-x

    Web of Science

    Scopus

    researchmap

  • Liquid-like dielectric response is an origin of long polaron lifetime exceeding 10 μs in lead bromide perovskites. 国際誌

    Kiyoshi Miyata, Ryota Nagaoka, Masaki Hada, Takanori Tanaka, Ryuji Mishima, Taihei Kuroda, Sota Sueta, Takumi Iida, Yoshifumi Yamashita, Takeshi Nishikawa, Kenji Tsuruta, Yasuhiko Hayashi, Ken Onda, Toshihiko Kiwa, Takashi Teranishi

    The Journal of chemical physics   152 ( 8 )   084704 - 084704   2020年2月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:AMER INST PHYSICS  

    Lead halide perovskites are promising materials for optoelectronic applications because of their exceptional performances in carrier lifetime and diffusion length; however, the microscopic origins of their unique characteristics remain elusive. The organic-inorganic hybrid perovskites show unique dielectric functions, i.e., ferroelectric-like phonon responses in the 0.1-10 THz region and liquid-like rotational relaxation in the 1-100 GHz range. To reveal the role of the dielectric responses is of primal importance because the dielectric screening is a key to understanding the optoelectronic properties governed by polarons in the perovskites. Here, we conducted comparative studies of broadband dielectric spectroscopy on both all-inorganic CsPbBr3 and organic-inorganic hybrid (CH3NH3)PbBr3 single crystals to uncover the origin of the liquid-like dielectric relaxation in the 1-100 GHz range. We confirmed the absence of the dielectric response in the range of 106-1010 Hz in CsPbBr3, which was clearly present in the hybrid (CH3NH3)PbBr3. This suggests that the response is almost purely due to the rotational motions of the organic dipoles in the hybrid perovskites. We evaluated the lifetimes of the polarons using surface-free transient photoluminescence. The lifetime in CsPbBr3 was up to 1.6 µs, while the lifetime in (CH3NH3)PbBr3 was 18 µs. The lifetime in the hybrid (CH3NH3)PbBr3 was significantly longer than in CsPbBr3, also confirmed by transient infrared spectroscopy. We concluded that the liquid-like dielectric response inhibits polaron recombination due to the efficient separation of opposite charges by the additional dynamic disorder.

    DOI: 10.1063/1.5127993

    Web of Science

    Scopus

    PubMed

    researchmap

  • Laser monitoring of dynamic behavior of magnetic nanoparticles in magnetic field gradient

    Kenta Tsunashima, Katsuya Jinno, Bunta Hiramatsu, Kayo Fujimoto, Kenji Sakai, Toshihiko Kiwa, Mohd Mawardi Saari, Keiji Tsukada

    AIP Advances   10 ( 1 )   2020年1月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:AMER INST PHYSICS  

    © 2020 Author(s). Manipulation of magnetic nanoparticles (MNP) by an external magnetic field has been widely studied in the fields of biotechnology and medicine for collecting and/or reacting biomaterials in the solutions. Here, dynamic behaviors of MNP in solution under changing gradient magnetic field were investigated using our newly developed laser transmission system (LTS) with a variable magnetic field manipulator. The manipulator consists of a moving permanent magnet placed beside the optical cell filled with MNP solution. A laser beam was focused on the cell and the transmitted laser beam was detected by a silicon photodiode, so that the localized concentration of the MNP at the focused area could be evaluated by the intensity of transmitted laser beam. In this study, the LTS was applied to evaluate dynamic behaviors of MNP in serum solution. Dispersion and aggregation of MNP in the solution were evaluated. While time evolution of dispersion depends on the serum concentration, the behavior during aggregation by the magnetic field was independent of the serum concentration. A series of measurements for zeta-potentials, distributions of particle size, and magnetization distributions was carried out to understand this difference in the behavior. The results indicated that a Brownian motion was main force to distribute the MNP in the solution; on the other hand, the magnetic force to the MNP mainly affected the behavior during aggregation of the MNP in the solution.

    DOI: 10.1063/1.5130167

    Web of Science

    Scopus

    researchmap

  • Magnetic characterization change by solvents of magnetic nanoparticles in liquid-phase magnetic immunoassay

    Katsuya Jinno, Bunta Hiramatsu, Kenta Tsunashima, Kayo Fujimoto, Kenji Sakai, Toshihiko Kiwa, Keiji Tsukada

    AIP Advances   9 ( 12 )   2019年12月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:AMER INST PHYSICS  

    © 2019 Author(s). Liquid-phase magnetic immunoassay (MIA) using magnetic nano-particles (MNPs) has been studied as a more rapid method compared to optical methods for inspecting proteins and viruses. MIA can estimate the number of conjugated antibodies without being washed differently from conventional optical immunoassay. However, in the case of the liquid phase, it is considered that the magnetic properties of MNPs are affected by physical properties such as viscosity and impurity substances such as biological substances contained in the blood. In this study, the effect of sodium chloride (NaCl) in buffer and serum solution was evaluated to reveal the effect of serum because the sodium (Na+) and chloride (Cl-) ions in the serum dominate ion balance of blood. The measurement results of AC magnetic susceptibility and a dynamic light scattering (DLS) showed that the aggregation of MNPs was largely affected by the concentration of NaCl. This effect of the NaCl could be explained by shielding of the surface charge of MNPs by ions in the solution. Although the concentrations of NaCl in the buffer and serum solution were almost same, we found that MNPs were aggregated more in their size for those in the serum solution because of other impurities, such as proteins. These results suggest evaluation of effects of the contaminants in serum and optimization of polymer coatings of MNPs could be important factors to realize measurements of magnetic immunoassay with high accuracy.

    DOI: 10.1063/1.5130168

    Web of Science

    Scopus

    researchmap

  • One-Minute Joule Annealing Enhances the Thermoelectric Properties of Carbon Nanotube Yarns via the Formation of Graphene at the Interface 査読

    Masaki Hada, Taisuke Hasegawa, Hirotaka Inoue, Makito Takagi, Kazuki Omoto, Daiki Chujo, Shogo Iemoto, Taihei Kuroda, Taiga Morimoto, Takuma Hayashi, Toru Iijima, Tomoharu Tokunaga, Naoshi Ikeda, Kazuhiro Fujimori, Chihiro Itoh, Takeshi Nishikawa, Yoshifumi Yamashita, Toshihiko Kiwa, Shin ya Koshihara, Satoshi Maeda, Yasuhiko Hayashi

    ACS Applied Energy Materials   2 ( 10 )   7700 - 7708   2019年10月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:AMER CHEMICAL SOC  

    © 2019 American Chemical Society. Interfaces in nanocarbon materials are highly important, as they determine the properties of carbon-based devices. In terms of carrier and thermal transport properties, the interfacial features are often more important than the intrinsic characteristics. Herein, we describe how 1 min Joule annealing of carbon nanotube (CNT) yarns can convert the interfacial amorphous carbon into graphene fragments. After 1 min Joule annealing, we have obtained multiwalled CNT yarns with extremely high Seebeck coefficients (±100 μV/K) and high thermoelectric power factor (400 and 1000 μW/mK2) at room temperature, both with or without polyethylenimine doping. Theoretical simulations and experimental measurements helped to determine the optimal annealing conditions in terms of a rapid transformation of the interfacial amorphous carbon between the bundled CNTs in the yarn into graphene fragments at â¼2000 K. The present approach represents significant progress in energy materials science, as it provides a guiding principle for the design of interfaces in nanocarbon materials with potential applications in energy-harvesting systems.

    DOI: 10.1021/acsaem.9b01736

    Web of Science

    Scopus

    researchmap

  • Influence of Viscosity on Dynamic Magnetization of Thermally Blocked Iron Oxide Nanoparticles Characterized by a Sensitive AC Magnetometer

    Mohd Mawardi Saari, Nazatul Shareena Suhaimi, Mohd Herwan Sulaiman, Nurul Akmal Che Lah, Kenji Sakai, Toshihiko Kiwa, Keiji Tsukada

    Journal of Superconductivity and Novel Magnetism   32 ( 9 )   2765 - 2772   2019年9月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:SPRINGER  

    © 2019, Springer Science+Business Media, LLC, part of Springer Nature. In this work, we show that the viscosity of carrier liquid affects the dynamic magnetization of thermally blocked multi-core iron oxide nanoparticles. The core size of the nanoparticles was determined from the magnetization curve measured by a specially developed high-Tc SQUID magnetometer and calculated to be 11.7 nm. Using an AC magnetometer developed based on induction coils, the dynamic magnetization of the multi-core iron oxide nanoparticle solution was measured from 3 Hz to 10.48 kHz. Later, we reconstructed of the hydrodynamic size distribution of the particles by assuming a log-normal distribution of particle size in an AC susceptibility model by Shliomis and Stepanov, which accounts for anisotropic directions of the easy axes of magnetic nanoparticles with respect to the excitation field direction. The reconstructed hydrodynamic sizes showed an average diameter of 130 nm and agreed with the size determined by dynamic light scattering method. In the case of increasing viscosity of the carrier liquids from 0.89 to 8.11 mPa s, the dynamic magnetization peaks of the imaginary component have shifted to a lower frequency region. We showed that the harmonics ratio and phase delay upon the magnetic field excitation at 30 Hz could also be used to determine the viscosity of carrier liquid independently.

    DOI: 10.1007/s10948-019-5031-6

    Web of Science

    Scopus

    researchmap

  • Development of a Highly Sensitive Magnetic Field Detector with a Wide Frequency Range for Nondestructive Testing Using an HTS Coil with Magnetic Sensors 査読

    Tetsuro Hirata, Yuto Goda, Kenji Sakai, Toshihiko Kiwa, Seiji Adachi, Akira Tsukamoto, Tsunehiro Hato, Keiichi Tanabe, Keiji Tsukada

    IEEE Transactions on Applied Superconductivity   29 ( 5 )   2019年8月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC  

    © 2002-2011 IEEE. To perform an early stage detection of the deterioration of steel parts used in infrastructures, a nondestructive testing (NDT) method is required, which is capable of evaluating hidden parts such as a steel deck covered with an asphalt pavement. To achieve this, a magnetic field detector should be sufficiently large to detect magnetic fields over a wide range to account for high lift-off. In addition, the detector must be capable of functioning at high frequencies for a high-speed inspection of surface cracks, and at low frequencies to compensate for the skin effect during the inspection of inner or rear side cracks. In this paper, we developed a magnetic field detector for eddy current testing in a wide frequency range by combining a high-temperature superconducting (HTS) coil made using DI-BSCCO tapes with a tunnel magnetoresistive (TMR) sensor. The TMR sensor was attached on the inside of the loop of the HTS coil to maximize the shielding characteristic. We applied the developed system to NDT, which can detect a signal from an artificial crack with a lift-off of 75 mm, which is greater than the thickness of the asphalt pavement. In addition, inner cracks that are 2.7 mm beneath the surface can be detected with a 10 Hz applied magnetic field.

    DOI: 10.1109/TASC.2019.2904485

    Web of Science

    Scopus

    researchmap

  • Extraction Method of Crack Signal for Inspection of Complicated Steel Structures Using A Dual-Channel Magnetic Sensor. 国際誌

    Minoru Hayashi, Taisuke Saito, Yoshihiro Nakamura, Kenji Sakai, Toshihiko Kiwa, Izumi Tanikura, Keiji Tsukada

    Sensors (Basel, Switzerland)   19 ( 13 )   2019年7月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:MDPI  

    Conventional eddy current testing (ECT) using a pickup coil probe is widely employed for the detection of structural cracks. However, the inspection of conventional ECT for steel structures is difficult because of the magnetic noise caused by the nonuniform permeability of steel. To combat this challenge, we have developed a small magnetic sensor probe with a dual-channel tunneling magnetoresistance sensor that is capable of reducing magnetic noise. Applying this probe to a complicated component of steel structures-such as the welds joining a U-shaped rib and deck plate together-requires the reduction of signal fluctuation caused by the distance (liftoff) variations between the sensor probe and the subject. In this study, the fundamental crack signal and the liftoff signal were investigated with the dual-channel sensor. The results showed that the liftoff signals could be reduced and differentiated from the crack signals by the differential parameters of the dual-channel sensor. In addition, we proposed an extraction technique for the crack signal using the Lissajous curve of the differential parameters. The extraction technique could be applied to the inspections not only for flat plates but also for welded angles to detect cracks without the influence of the liftoff signal.

    DOI: 10.3390/s19133001

    Web of Science

    Scopus

    PubMed

    researchmap

  • Using Magnetic Field Gradients to Shorten the Antigen-Antibody Reaction Time for a Magnetic Immunoassay

    Keiji Tsukada, Kenta Tsunashima, Katsuya Jinno, Bunta Hiramatsu, Shun Takeuchi, Kayo Fujimoto, Kenji Sakai, Toshihiko Kiwa, Mohd Mawardi Saari

    IEEE Transactions on Magnetics   55 ( 7 )   2019年7月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC  

    © 1965-2012 IEEE. The measurement of biological targets using nanoparticle magnetic markers has been extensively studied for its applications in magnetic immunoassays (MIAs). Compared with the optical immunoassay method, the MIA methods have some attractive characteristics such as a wash-free process that does not need bound/free marker separation and the ability to detect biological targets in a nebulous liquid. In addition, the wash-free process is very fast. In this paper, we tried to reduce the reaction time for the antigen-antibody reaction in order to make the MIA method more attractive. The reduction in reaction time and the detection characteristic of biological targets were demonstrated using C-reactive proteins (CRPs) as biological targets for diagnosing inflammation. To shorten the reaction time, a magnetic-shaking method using the magnetic field gradient from a neodymium magnet was developed. When comparing the reaction times with and without magnetic shaking, it was found that the reaction time decreased with magnetic shaking for all CRP concentrations. Even after the magnetic-shaking treatment, the dependence of the CRP concentration on the magnetic signal was observed. The number of surface modifications per magnetic marker and the magnetic marker concentration also affected the reaction time. In order to obtain the desired measurement range based on the CRP response characteristic, it is necessary to optimize the number of magnetic markers and polymer beads used.

    DOI: 10.1109/TMAG.2019.2894904

    Web of Science

    Scopus

    researchmap

  • Improvement of contrast of Terahertz Images of a Terahertz Chemical Microscopy using Adaptive Digital Filter

    Feroz Ahmed, Tatsuki Kamiya, Yuki Maeno, Toshihiko Kiwa, Kenji Sakai, Keiji Tsukada

    5th International Conference on Computer, Communication, Chemical, Materials and Electronic Engineering, IC4ME2 2019   2019年7月

     詳細を見る

    掲載種別:研究論文(国際会議プロシーディングス)  

    © 2019 IEEE. A Terahertz Chemical Microscope has been proposed and developed for the visualization of chemical reactions in the solutions. To visualize chemical reactions with higher imaging quality and higher scanning speed, it is required to improve the contrast of the images. In this study, we applied an adaptive filter to the TCM system and evaluate the imaging quality qualitatively. The contrasts without filter and with filter are 0.33 and 0.74 respectively. This result shows that our system with the filter could improve the imaging quality without losing the scanning speed of the microscope.

    DOI: 10.1109/IC4ME247184.2019.9036485

    Scopus

    researchmap

  • High-sensitivity detection of metastatic breast cancer cells via terahertz chemical microscopy using aptamers 査読

    Eman M. Hassan, Ahmed Mohamed, Maria C. DeRosa, William G. Willmore, Yuki Hanaoka, Toshihiko Kiwa, Tsuneyuki Ozaki

    Sensors and Actuators, B: Chemical   287   595 - 601   2019年5月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ELSEVIER SCIENCE SA  

    © 2019 Elsevier B.V. We demonstrate high-sensitivity detection of metastatic breast cancer cells using terahertz (THz) chemical microscopy (TCM) with aptamers as ligands. For the aptamers, we use previously developed synthetic single stranded (ss) DNA aptamers mammaglobin B1 (MAMB1) and mammaglobin A2 (MAMA2) that bind to mammaglobin B and mammaglobin A proteins, respectively, which are overexpressed on the surface of MCF7 and MDA-MB-415 breast cancer cells. Each aptamer was immobilized on the surface of a sensing plate, and the amplitude of the THz signal was measured upon the binding of each aptamer to different number (10–106) of its target breast cancer cells. A change in the THz amplitude was observed when MAMB1 and MAMA2 bind to MCF7 and MDA-MB-415, respectively. We find that this change was linear as a function of the log number of breast cancer cells used. No change in the THz amplitude was observed when the same number of normal breast cells (MCF 10A) were used. Moreover, MAMB1 and MAMA2 did not show binding to the counter breast cancer cells, indicating high selectivity. We have demonstrated that the TCM using aptamers as ligands has a limit of detection as small as 1 breast cancer cell in 100 μL of sample. Results described here indicate that the TCM could be a powerful tool to detect metastatic breast cancer cells.

    DOI: 10.1016/j.snb.2019.02.019

    Web of Science

    Scopus

    researchmap

  • Hybrid Magnetic Sensor Combined with a Tunnel Magnetoresistive Sensor and High-Temperature Superconducting Magnetic-Field-Focusing Plates 査読

    Keiji Tsukada, Tetsuro Hirata, Yuto Goda, Kenji Sakai, Toshihiko Kiwa

    IEEE Transactions on Applied Superconductivity   29 ( 3 )   2019年4月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC  

    © 2002-2011 IEEE. Magnetoresistive (MR) sensors are widely used, particularly in consumer products. However, in applications requiring extremely sensitive magnetic sensors, superconducting quantum interference devices (SQUIDs) are primarily used. In this study, we develop a hybrid magnetic sensor by combining an MR sensor with two high-temperature superconducting (HTS) plates to achieve sensitivity that lies between those of MR sensors and SQUIDs. In addition, we apply a modulation method for measuring the absolute magnetic field. A nanogranular in-gap tunnel MR sensor is installed inside the slit between the magnetic-field-focusing HTS plates, and the magnetic response is evaluated. Using the magnetic-field-focusing characteristics of the HTS plates (made from YBa2Cu3O7-δ) and the MR sensor inside the slit between the two plates, the sensitivity and noise characteristics are improved. Adjustment of parameters, such as MR sensor height from the slit, slit width of the HTS plates, and plate size allow sensitivity control depending on the application. Moreover, the absolute magnetic response and low noise in low-frequency regions are obtained through ac modulation.

    DOI: 10.1109/TASC.2018.2874354

    Web of Science

    Scopus

    researchmap

  • Imaging of chemical reactions using a terahertz chemical microscope 査読

    Toshihiko Kiwa, Tatsuki Kamiya, Taiga Morimoto, Kentaro Fujiwara, Yuki Maeno, Yuki Akiwa, Masahiro Iida, Taihei Kuroda, Kenji Sakai, Hidetoshi Nose, Masaki Kobayashi, Keiji Tsukada

    Photonics   6 ( 1 )   2019年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:MDPI  

    © 2019 by the authors. This study develops a terahertz (THz) chemical microscope (TCM) that visualizes the distribution of chemical reaction on a silicon-based sensing chip. This chip, called the sensing plate, was fabricated by depositing Si thin films on a sapphire substrate and thermally oxidizing the Si film surface. The Si thin film of the sensing plate was irradiated from the substrate side by a femtosecond laser, generating THz pulses that were radiated into free space through the surface field effect of the Si thin film. The surface field responds to chemical reactions on the surface of the sensing plate, changing the amplitude of the THz pulses. This paper first demonstrates the principle and experimental setup of the TCM and performs the imaging and measurement of chemical reactions, including the reactions of bio-related materials.

    DOI: 10.3390/photonics6010010

    Web of Science

    Scopus

    researchmap

  • Integrated Magnetic Sensor Probe and Excitation Wire for Nondestructive Detection of Submillimeter Defects

    Keiji Tsukada, Hiroto Shobu, Yuto Goda, Takumi Kobara, Kenji Sakai, Toshihiko Kiwa, Mohd Mawardi Saari

    IEEE Magnetics Letters   10   2019年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC  

    © 2010-2012 IEEE. Eddy current testing with excitation and pickup coils is widely used to detect defects in metals. The detection of submillimeter defects is difficult because of limitations on pickup coil size. We have developed an integrated magnetic probe for detecting submillimeter defects in both nonmagnetic and ferromagnetic materials. The sensor probe consists of a tunneling magnetoresistance (TMR) device and an excitation wire. This probe can apply small, localized magnetic fields to a sample that is near the TMR sensor. The direction of the field excitation is perpendicular to the sensing direction of the TMR sensor to minimize magnetic coupling between the excitation wire and the sensor. A change in the line-scanned signal was detected when measuring pits from 0.5 mm to 1.0 mm in diameter at depths of more than 0.1 mm in both steel and aluminum plates. Signal changes depended on defect size. As the frequency was increased from 1 kHz to 50 kHz, the defect signal change for the aluminum plate increased due to an increase in eddy currents. A clear defect signal for the steel plate was obtained even at a low frequency of 1 kHz because the detected signal for steel consists of a frequency-dependent eddy-current component and a magnetization component even at low frequencies.

    DOI: 10.1109/LMAG.2019.2936392

    Web of Science

    Scopus

    researchmap

  • Magnetic NDE system for detection of crack in steel deck with high lift-off using secondary differential detection coil

    Yuto Goda, Hiroto Shobu, Takumi Kobara, Kenji Sakai, Toshihiko Kiwa, Akira Tsukamoto, Keiichi Tanabe, Keiji Tsukada

    10th International Workshop NDT in Progress   2019年

     詳細を見る

    掲載種別:研究論文(国際会議プロシーディングス)  

    © International Workshop NDT.All rights reserved. Recently, the aging of buildings and infrastructure facilities is becoming a social problem. In the steel structure, the nondestructive evaluation with high lift-off is required to inspect the steel material under the asphalt or concrete, such as the steel floor slabs of roads. Under the high lift-off condition, the influence of the magnetic noise and applied magnetic field should be reduced because the signal from the crack is small. In order to reduce the influence of the magnetic noise, in this study, the detection of crack signal by eddy current testing was examined using a detection coil of a differential coil. This differential coil is a secondary differential coil combining two differential coils aiming for improving the signal to noise ratio (SNR) by reducing the influence of the magnetic noise and applied magnetic field. Using this secondary differential coil, the crack with high liftoff of 80 mm was detected, and it is expected to detect the cracks in steel structures located under the asphalt or concrete.

    Scopus

    researchmap

  • Design of eddy current testing probe for surface defect evaluation

    M. M. Saari, N. A. Nadzri, A. M. Halil, M. Ishak, K. Sakai, T. Kiwa, K. Tsukada

    International Journal of Automotive and Mechanical Engineering   16 ( 1 )   6357 - 6367   2019年

     詳細を見る

    掲載種別:研究論文(学術雑誌)  

    © Universiti Malaysia Pahang, Malaysia. Early detection of defects in metallic components used in infrastructure is crucial to ensure their safety and reliability. This paper presents a development of a small eddy current testing (ECT) probe for evaluation of sub-millimetre surface defects. The ECT probe is developed in a planar differential using sensitive anisotropy magnetoresistance sensors, and the signal amplification is achieved by a home-made instrumentation amplifier. The developed ECT probe is evaluated by performing phase sensitive measurement of the magnetic responses of sub-millimetre surface slits at the excitation field of 200 Hz and 10 kHz. Compared to the real component of the magnetic response, the imaginary component can be used to identify the existence and position of the slits based on the signal intensity change caused by the induced eddy current. The spatial distribution of the magnetic response measured by the ECT probe can be used to estimate the dimension of the slit. It is expected that the developed ECT probe can be utilised for assessment of sub-millimetre surface defect.

    DOI: 10.15282/ijame.16.1.2019.19.0481

    Scopus

    researchmap

  • Detection of lung cancer cells using a terahertz chemical microscope

    Kosuke Sato, Masahiro Iida, Hirofumi Inoue, Toshihiko Kiwa, Shinichi Toyooka, Keiji Tsukada

    Optics InfoBase Conference Papers   Part F146-JSAP 2019   2019年

     詳細を見る

    掲載種別:研究論文(国際会議プロシーディングス)  

    © 2019 OSA - The Optical Society. All rights reserved. We have developed the TCM to evaluate the ration of cancer cells to normal cells for realizing the cancer genome therapy. The THz amplitude radiated from the sensing plate increased by increasing the cell population of lung cell carcinoma.

    Scopus

    researchmap

  • Optimization of inclined angle magnetic sensor probe to improve detection performance of corrosion near the ground using extremely low-frequency eddy current testing

    Shunki Wakabayashi, Minoru Hayashi, Taisuke Saitoh, Kenji Sakai, Toshihiko Kiwa, Keiji Tsukada

    10th International Workshop NDT in Progress   2019年

     詳細を見る

    掲載種別:研究論文(国際会議プロシーディングス)  

    © International Workshop NDT.All rights reserved. As the aging of steel pipes used for sign pole is caused by the corrosion near ground, a quantitative evaluation of the corrosion location and thinning rate from the ground surface is required. Therefore, we have proposed a magnetic nondestructive testing for the steel pipes using two magnetic sensors, and it was possible to inspect the underground corrosion defects. However, in order to improve the accuracy of estimating the thinning rate and position of underground corrosion, the optimization of the inclination angle of the magnetic sensor probe and the distance between two magnetic sensors has been required. Therefore, in order to extract the signal change caused by the thinning rate of the test sample and the measurement distance, the distance dependence which is the relationship between the signal intensity and the measurement distance was measured and the measured value was normalized by the signal intensity measured at uncorroded area. As a result, the difference between the signal intensity at the uncorroded part and that near the corrosion defect could be clearly extracted. Furthermore, the rate of change of signal intensity increased by changing the tilt angle of probe and the distance between two sensors. Using the optimized magnetic sensor probe and applying the normalized distance dependence, we succeeded in the quantitative evaluation of the thinning rate and position of corrosion defects.

    Scopus

    researchmap

  • Optimization of applied magnetic field methods for various shape defects by eddy current testing using magneto resistive sensor

    Takumi Kobara, Yuto Goda, Hiroto Shobu, Kenji Sakai, Toshihiko Kiwa, Keiji Tsukada

    10th International Workshop NDT in Progress   2019年

     詳細を見る

    掲載種別:研究論文(国際会議プロシーディングス)  

    © International Workshop NDT.All rights reserved. In this study, we investigated the optimization of applied magnetic field methods for defect detection for various shapes of defects made of magnetic and non-magnetic materials using the eddy current testing with a highly sensitive magnetic sensor. From the experiment and simulation results, it was found that the change of the magnetic field distribution caused by the eddy current increased when the sensor was placed directly above the induction coil of the wire-type method. Moreover, in the solenoid coil system, it was found that the detection sensitivity increased when the magnetic sensor was placed close to one side of the coil compared to that placed at the center. In addition, it was found that the signal change was different in the electromagnetic characteristics of the measurement sample. For the non-magnetic material, as the frequency increased, the signal to noise ratio (SNR) of the detected defect signal increased because the signal was generated from only the eddy current. On the other hand, for the magnetic material, there was an optimum frequency for detecting the defect because the signal was generated due to both the magnetization and the eddy current. As a results, the optimum applying method of magnetic field for the eddy current testing using magnetic sensor was clarified.

    Scopus

    researchmap

  • The nondestructive evaluation of penetration of the cosmetic liquid into the pig skin

    Sota Sueda, Taihei Kuroda, Kenji Sakai, Toshihiko Kiwa, Keiji Tsukada

    Optics InfoBase Conference Papers   Part F146-JSAP 2019   2019年

     詳細を見る

    掲載種別:研究論文(国際会議プロシーディングス)  

    Scopus

    researchmap

  • Measurement of ion concentration in the solution without reference electrodes using a terahertz chemical microscopy

    Atsuya Mahana, Yuki Maeno, Kenji Sakai, Toshihiko Kiwa, Keiji Tsukada

    Optics InfoBase Conference Papers   Part F146-JSAP 2019   2019年

     詳細を見る

    掲載種別:研究論文(国際会議プロシーディングス)  

    © 2019 OSA - The Optical Society. All rights reserved. A terahertz chemical microscopy (TCM) has been proposed and developed for measuring pH and the ion concentration with the multiple and small volume of solutions simultaneously. By fabricating multiple wells on the sensing plate to measure standard solutions, quantitative measurement of ions could be possible without any reference electrodes.

    Scopus

    researchmap

  • Magnetic detection of steel corrosion at a buried position near the ground level using a magnetic resistance sensor 査読

    Keiji Tsukada, Takuya Tomioka, Shunki Wakabayashi, Kenji Sakai, Toshihiko Kiwa

    IEEE Transactions on Magnetics   54 ( 11 )   2018年11月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC  

    © 1965-2012 IEEE. Corrosion of steel structures, such as lighting and road marker poles, located in close proximity to or buried within the ground have become a social problem. Steel corrosion has been observed to occur rather easily near the ground level. However, corrosion detection in parts of steel structures buried within the ground is very difficult. To address this concern, a magnetic resistance testing system for detecting corrosion in buried steel structures has been developed using a tilted magnetic sensor probe, and it is based on our independently developed extremely low-frequency eddy-current testing methodology. The magnetic sensor probe comprises an anisotropic magnetic resistance sensor, induction coil, and small cancellation coil. The applied magnetic field was operated at extremely low frequencies between 1 and 100 Hz, and the magnetic spectrum, which was traced using the real and imaginary parts of the detected magnetic signal at each frequency, was analyzed for estimating changes in steel thickness. Test samples comprising 4 mm thick stainless steel plates with a partial thinning zone varying in depth between 0.5 and 3.0 mm were used during measurements. Changes in thickness were detected at locations other than the thinning zone by using the differential-magnetic-intensity-subtracted magnetic vector of frequency 1 Hz from that of frequency 20 Hz detected by the tilted magnetic sensor probe. Moreover, the depth of corrosion and its corresponding location beneath the ground level were estimated via measuring techniques involving the use of magnetic sensor probes in the separated position or at different tilt angles in the same position.

    DOI: 10.1109/TMAG.2018.2833852

    Web of Science

    Scopus

    researchmap

  • Evaluation of Li-ion battery using a Terahertz Chemical Microscope 査読

    Yuki Akiwa, Kentarou Fujiwara, Yumi Yoshikawa, Takashi Teranishi, Kenji Sakai, Toshihiko Kiwa, Keiji Tsukada

    International Conference on Infrared, Millimeter, and Terahertz Waves, IRMMW-THz   2018-September   2018年10月

     詳細を見る

    担当区分:責任著者   記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:IEEE  

    © 2018 IEEE. We measured the terahertz wave intensity of the active material surface using TCM as a method to evaluate lithium ion batteries. We made a battery with a sensing plate attached to measure with TCM. As a result, changes in the terahertz wave intensity due to charging and discharging of the battery could be measured. This result indicates that the extraction and insertion of lithium in the active material can be measured by TCM in the future.

    DOI: 10.1109/IRMMW-THz.2018.8509878

    Web of Science

    Scopus

    researchmap

  • Detection of Ions in Solutions with Sub-Micro Liter Volumes Using a Terahertz Chemical Microscope

    Y. Maeno, T. Kamiya, T. Kiwa, K. Sakai, K. Tsukada

    International Conference on Infrared, Millimeter, and Terahertz Waves, IRMMW-THz   2018-September   2018年10月

     詳細を見る

    掲載種別:研究論文(国際会議プロシーディングス)  

    © 2018 IEEE. A terahertz chemical microscope (TCM) has been proposed and developed for measuring the small volume of the ion concentrations in solutions. By fabricating the small solution wells and the ion selective membranes on the sensing plate, the concentration of the sodium ions in the solution of 450 nL could be measured.

    DOI: 10.1109/IRMMW-THz.2018.8510464

    Scopus

    researchmap

  • Concentration Dependence of IgG Immobilized on a Sensing Plate for Higher Sensitivity of a Terahertz Chemical Microscope

    M. Iida, T. Kamiya, K. Sakai, T. Kiwa, K. Tukada

    International Conference on Infrared, Millimeter, and Terahertz Waves, IRMMW-THz   2018-September   2018年10月

     詳細を見る

    掲載種別:研究論文(国際会議プロシーディングス)  

    © 2018 IEEE. We have developed a terahertz chemical microscope for measuring immune reactions without any label. Here, to evaluate the relation between the concentration of IgG immobilized on the sensing plate and the sensitivity of the system, the concentration dependence of the IgG was evaluated.

    DOI: 10.1109/IRMMW-THz.2018.8509884

    Scopus

    researchmap

  • A sensitive AC magnetometer using a resonant excitation coil for magnetic fluid characterization in nonlinear magnetization region 査読

    Mohd Mawardi Saari, Nazatul Sharreena Suhaimi, Nurul Akmal Che Lah, Kenji Sakai, Toshihiko Kiwa, Keiji Tsukada

    2018 IEEE International Magnetic Conference, INTERMAG 2018   2018年10月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:IEEE  

    © 2018 IEEE. In order to tailor the magnetic nanoparticles (MNPs) properties for intended applications, it is crucial to unravelling their fundamental dynamics with respect to excitation magnetic field. In this work, we report on the development of a sensitive AC magnetometer using a resonant excitation coil for this purpose. The excitation coil fabricated from a Litz wire is connected to a capacitor network to reduce the impedance of the circuit efficiently. The high efficiency showed by the excitation coil enables investigation of MNP's dynamics in the nonlinear magnetization region. We demonstrate the sensitivity of the developed system by measuring the harmonics distribution of multi-core iron oxide nanoparticles suspended in solutions with the iron concentration down to 300 ng/ml. We experimentally show that the first harmonic component is not entirely 'transparent' to the diamagnetic background of the carrier liquid compared to the higher harmonics. We also demonstrate the complex magnetization measurement of the iron oxide nanoparticles in solution and immobilized states from 3 Hz to 18 kHz. A highly sensitive exploration of MNPs' dynamics can be expected using the developed AC magnetometer.

    DOI: 10.1109/INTMAG.2018.8508784

    Web of Science

    Scopus

    researchmap

  • Sensitivity Improvement of Sample Rotation Measurement Method in HTS-SQUID Magnetometer for Diamagnetic Materials 査読

    Yuta Nakamura, Ryota Isshiki, Shun Takeuchi, Tetsuro Hirata, Kenji Sakai, Toshihiko Kiwa, Keiji Tsukada

    IEEE Transactions on Applied Superconductivity   28 ( 4 )   2018年6月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC  

    © 2002-2011 IEEE. Measuring extremely low magnetic signals of diamagnetic materials such as water and ethanol with high sensitivity is important in various fields. Ethanol is widely used as a solvent in areas such as chemical industry and drug discovery; therefore, it is important to measure its concentration with high sensitivity. We have already reported a hybrid-type magnetometer using a high temperature superconductor superconducting quantum interference device (HTS-SQUID), which can measure and evaluate magnetic characteristics by vibrating and rotating a sample. However, the signal-to-noise ratio (SNR) of the system needs to be improved as magnetic signals from diamagnetism in water and ethanol are extremely low in magnitude. In this study, digital frequency filters were applied to the signals measured by the HTS-SQUID magnetometer with a rotating sample container in order to improve the SNR of the system, and then the magnetic properties of ethanol and water were studied. As a result, the SNR of the system improved about twice the level obtained by conventional signal processing method.

    DOI: 10.1109/TASC.2018.2810088

    Web of Science

    Scopus

    researchmap

  • Evaluation of the Magnetization Properties of Magnetic Nanoparticles in Serum Using HTS-SQUID 査読

    Ryota Isshiki, Yuta Nakamura, Shun Takeuchi, Tetsuro Hirata, Kenji Sakai, Toshihiko Kiwa, Keiji Tsukada

    IEEE Transactions on Applied Superconductivity   28 ( 4 )   2018年6月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC  

    © 2018 IEEE. The magnetization properties of magnetic nanoparticles (MNPs) changed by the action of the buffer and serum solutions with different viscosities were analyzed using dc and ac magnetometers that utilized high-temperature superconductivity-superconducting quantum interference devices. The magnetization properties of MNPs in different solutions with different viscosities were measured using a dc magnetometer via vibrating the sample under a dc magnetic field. The harmonic signal characteristics of the MNPs in different solutions were measured in a low-frequency magnetic field. In addition, the dynamic changes in the magnetic characteristics of MNPs in different solutions were measured using an ac magnetometer with a high frequency. The results corresponding to the low- and high-frequency fields showed that both viscosity of the solvent and the interactions between the MNPs and the solvent are important influencing factors in immunoassays using MNPs.

    DOI: 10.1109/TASC.2018.2795619

    Web of Science

    Scopus

    researchmap

  • Analysis of AC Impedance in Localized Region Using Magnetic Field Distribution Measured by HTS-SQUID 査読

    Kenji Sakai, Tsubasa Kizu, Toshihiko Kiwa, Keiji Tsukada

    IEEE Transactions on Applied Superconductivity   28 ( 4 )   2018年6月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC  

    © 2002-2011 IEEE. Estimation of ac impedance in a localized region was investigated by measuring the magnetic field from an electrical current induced by applying an ac voltage to a sample. For this measurement, a high-temperature-superconductor superconducting quantum interference device (HTS-SQUID) was used to detect a small magnetic field from a sample. To clarify the detection of ac impedance in a localized region, a dye-sensitized solar cell (DSSC) with a positive electrode consisting of two catalysis materials was prepared. Although the I-V characteristic and electrochemical impedance spectroscopy (EIS) of the solar cell with two catalysis materials were different from those of the solar cell with a one catalysis material, it was difficult to evaluate the ac impedance of the localized region. The magnetic field from the solar cell with two catalysis materials depended on the measurement position at which the catalysis material located under HTS-SQUID was different. This difference was correlated to the ac impedance change predicted by the measured EIS. Moreover, the mapping obtained by magnetic field distribution near the interface of two catalysis materials showed a different magnetic field intensity, which was correlated to the position of each catalysis material. These results indicate that the analysis of the localized ac impedance is possible using the magnetic field distribution generated from a sample.

    DOI: 10.1109/TASC.2018.2796609

    Web of Science

    Scopus

    researchmap

  • pH measurements in 16-nL-volume solutions using terahertz chemical microscopy. 査読 国際誌

    Toshihiko Kiwa, Tatsuki Kamiya, Taiga Morimoto, Kenji Sakai, Keiji Tsukada

    Optics express   26 ( 7 )   8232 - 8238   2018年4月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:OPTICAL SOC AMER  

    Terahertz chemical microscopy has been developed for measuring the pH of a solution using only a small volume. The microsolution wells were fabricated on the surface of the sensing plate using a conventional photolithograph technique. Because the pH value can be calculated from the amplitude of a terahertz wave directly radiated from a sensing plate by a femtosecond laser irradiation, this method does not require any reference electrode in the solution. Thus, pH measurement can be achieved with a volume as small as 16 nL.

    DOI: 10.1364/OE.26.008232

    Web of Science

    Scopus

    PubMed

    researchmap

  • Harmonics distribution of iron oxide nanoparticles solutions under diamagnetic background 査読

    Mohd Mawardi Saari, Nurul Akmal Che Lah, Kenji Sakai, Toshihiko Kiwa, Keiji Tsukada

    Journal of Magnetism and Magnetic Materials   452   145 - 152   2018年4月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ELSEVIER SCIENCE BV  

    © 2017 Elsevier B.V. The static and dynamic magnetizations of low concentrated multi-core iron oxide nanoparticles solutions were investigated by a specially developed high-Tc Superconducting Quantum Interference Device (SQUID) magnetometer. The size distribution of iron oxide cores was determined from static magnetization curves concerning different concentrations. The simulated harmonics distribution was compared to the experimental results. Effect of the diamagnetic background from carrier liquid to harmonics distribution was investigated with respect to different intensity and position of peaks in the magnetic moment distribution using a numerical simulation. It was found that the diamagnetic background from carrier liquid of iron oxide nanoparticles affected the harmonics distribution as their concentration decreased and depending on their magnetic moment distribution. The first harmonic component was susceptible to the diamagnetic contribution of carrier liquid when the concentration was lower than 24 μg/ml. The second and third harmonics were affected when the peak position of magnetic moment distribution was smaller than m = 10−19 Am2 and the concentration was 10 ng/ml. A highly sensitive detection up to sub-nanogram of iron oxide nanoparticles in solutions can be achieved by utilizing second and third harmonic components.

    DOI: 10.1016/j.jmmm.2017.12.054

    Web of Science

    Scopus

    researchmap

  • Development of a resonant excitation coil of AC magnetometer for evaluation of magnetic fluid

    Mohd Mawardi Saari, Nazatul Sharreena Suhaimi, Saifudin Razali, Nurul Akmal Che Lah, Kenji Sakai, Toshihiko Kiwa, Keiji Tsukada

    Journal of Telecommunication, Electronic and Computer Engineering   10 ( 1-2 )   127 - 130   2018年1月

     詳細を見る

    掲載種別:研究論文(学術雑誌)  

    © 2018 Universiti Teknikal Malaysia Melaka. All rights reserved. A high-homogeneity excitation coil with a resonant circuit for AC magnetometer is developed. A solenoid coil is designed to produce a high-homogeneity and strong excitation field using a resonant frequency method. The solenoid coil is fabricated with a Litz wire to suppress the increase of AC resistance due to the skin and proximity effects in the high-frequency region. The Litz wire is composed of 60 strands of copper wires with 0.1-mm diameter. The resonant frequency method is applied to cancel the reactance component by connecting the excitation coil with a capacitor in a series configuration. To enable excitation of the magnetic field at multiple frequencies, a resonant circuit consists of multiple values of resonant capacitors is constructed. The fabricated excitation coil showed a high homogeneity of the magnetic field and was able to maintain a constant resonant current up to 32.5 kHz.

    Scopus

    researchmap

  • Small Eddy Current Testing Sensor Probe Using a Tunneling Magnetoresistance Sensor to Detect Cracks in Steel Structures 査読

    Keiji Tsukada, Minoru Hayashi, Yoshihiro Nakamura, Kenji Sakai, Toshihiko Kiwa

    IEEE Transactions on Magnetics   54 ( 11 )   2018年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC  

    © 1965-2012 IEEE. An eddy current test (ECT) is a common nondestructive test to detect flaws in metal structures. Many ECTs use both a detection coil and an induction coil. The application of this method to ferromagnetic materials can be challenging because the applied magnetic field is composed of not only the eddy current but also the magnetization signal. Therefore, we developed two types of miniaturized ECT probes, namely, single-and dual-channel tunneling magnetoresistance (TMR) probes, by using a TMR sensor instead of a detection coil. To evaluate the performance of crack detection in steel with regard to the length, width, and depth of cracks, the sensor probe was line-scanned above the crack position. The output signal was detected using a lock-in amplifier and analyzed using the real and imaginary components of a magnetic vector. The detected signal was then divided into the magnetization and eddy current components. The dual TMR sensor probe installed inside the induction coil could yield a stable crack signal without the influence of magnetization fluctuation. The line-scanned differential signal intensity and phase show a signal change with a high signal-to-noise ratio at the crack position. These signals depend on the width and length of the crack. A 2-D scanning could provide a magnetic map corresponding to the crack shape.

    DOI: 10.1109/TMAG.2018.2845864

    Web of Science

    Scopus

    researchmap

  • Evaluation of penetration of cosmetic liquid with Terahertz time-of-flight method

    Taiga Morimoto, Taihei Kuroda, Kenji Sakai, Toshihiko Kiwa, Keiji Tsukada

    Optics InfoBase Conference Papers   Part F113-CLEOPR 2018   2018年

     詳細を見る

    掲載種別:研究論文(国際会議プロシーディングス)  

    © OSA 2018 A terahertz time-of-flight method has been developed to evaluate penetration of cosmetic liquid. By using a face mask as the reservoir of the cosmetic liquid, the evaluation from the horny layers could be realized.

    DOI: 10.1364/cleopr.2018.tu3c.5

    Scopus

    researchmap

  • Characterizing of corrosion backside of steel plates using extremely low-frequency eddy current testing with multiple-frequency magnetic-field exposure

    Tsuyoshi Goda, Yuta Haga, Takuya Tomioka, Kenji Sakai, Toshihiko Kiwa, Keiji Tsukada

    Studies in Applied Electromagnetics and Mechanics   43   130 - 135   2018年

     詳細を見る

    掲載種別:研究論文(国際会議プロシーディングス)  

    © 2018 The authors and IOS Press. In recent years, aging and deterioration of social infrastructure has become a major problem. A non-destructive testing technique for early detection of degradation (such as internal corrosion) is required to extend the lifetime of these structures. Currently, there are various methods used for inspection. Among these, non-destructive testing using magnetic fields is widely used due to advantages such as ease of use and high speed. However, magnetic inspection is generally employed only for inspection of the surface and subsurface, since it is difficult to inspect internal corrosion using this technique. Therefore, we have developed a device for detecting thinning of steel plates due to corrosion using multiple extremely-low frequencies and a high-sensitivity magnetic sensor. However, it is necessary to sweep multiple frequencies to obtain a frequency spectrum, and this is very timeconsuming, especially in extremely low-frequency ranges. In this study, we have developed an analysis method based on a multiple-frequency applied magnetic field and FFT (fast Fourier transform) analysis of the detection signal. Thus, we have successfully reduced the measurement time while maintaining high detection accuracy.

    DOI: 10.3233/978-1-61499-836-5-130

    Scopus

    researchmap

  • Detection Method Using a Dual-channel Magnetic Sensor for Steel Cracks in Complicated Structures

    Minoru Hayashi, Yoshihiro Nakamura, Kenji Sakai, Toshihiko Kiwa, Izumi Tanikura, Keiji Tsukada

    Proceedings of the 7th Asia-Pacific Workshop on Structural Health Monitoring, APWSHM 2018   580 - 586   2018年

     詳細を見る

    掲載種別:研究論文(国際会議プロシーディングス)  

    © APWSHM 2018. All rights reserved. Conventional eddy current testing (ECT) using a pickup coil is widely employed for detecting cracks. However, it is sometimes difficult to apply conventional ECT to steel structures because of the magnetic noise caused by the non-uniform permeability of steel. To combat this challenge, we developed a small magnetic sensor probe with dual-channel tunnelling magnetic resistance capable of reducing magnetic noise. To apply the developed magnetic sensor probe to a complicated component of a steel structure, such as the welds joining the U-rib and deck plate, signal fluctuations caused by the lift-off variations between the sensor probe and the subject during magnetic sensor probing must be resolved. Therefore, we developed a method to distinguish between the signal changes caused by lift-off variations and cracks. The intensity and phase of the subtracted signal were used to develop traces of differential parameters obtained by scanning the magnetic probe. A visualization technique using only the traces of differential parameters, i.e. the Lissajous curve of X-Y processing, was applied not only to the cracks of the flat steel plate but also to the cracks in welded angles. The developed Lissajous curve emphasized the crack signals, which allowed clear differences between the signal change caused by the lift-off variations and cracks to be observed.

    Scopus

    researchmap

  • Thickness measurements using extremely low frequency eddy current testing via TMR sensors operated with AC modulation

    Yatsuse Majima, Yoshihiro Nakamura, Kenji Sakai, Toshihiko Kiwa, Keiji Tsukada

    Studies in Applied Electromagnetics and Mechanics   43   199 - 204   2018年

     詳細を見る

    掲載種別:研究論文(国際会議プロシーディングス)  

    © 2018 The authors and IOS Press. Conventionally, eddy current testing (ECT) has been used for the surface crack detection. However, the detection of underside and internal corrosion was difficult using this technique. Therefore, we developed an underside and internal corrosion detection technique based on extremely low frequency ECT (ELECT). To use the TMR sensor for ELECT, a TMR sensor operated with AC modulation was applied as a magnetic sensor. Then, we developed the ELECT system using a TMR sensor operated with AC modulation, and succeeded in measuring the thickness of thick steel plate.

    DOI: 10.3233/978-1-61499-836-5-199

    Scopus

    researchmap

  • Improvement in the detection performance of extremely low-frequency eddy current testing for application in underground steel corrosion detection

    Shunki Wakabayashi, Takuya Tomioka, Kenji Sakai, Toshihiko Kiwa, Keiji Tsukada

    Proceedings of the 7th Asia-Pacific Workshop on Structural Health Monitoring, APWSHM 2018   512 - 518   2018年

     詳細を見る

    掲載種別:研究論文(国際会議プロシーディングス)  

    © APWSHM 2018. All rights reserved. The corrosion of steel structures, such as light and road sign poles, often occurs near the ground due to rainwater. The subsequent collapse of the corresponding steel structure can cause traffic accidents and potentially danger people. Therefore, a highly accurate and easy nondestructive inspection technique is required to detect corrosion near the ground, especially in hidden locations. Recently, we reported a novel inspection method using extremely low-frequency eddy current testing (ELECT) to detect the reduced steel thickness that was caused by corrosion. Wide magnetic-field exposure was achieved underground using a tilted magnetic sensor probe. Further, the fundamental detection performance and signal analysis of the test samples were also reported. In this study, we attempted to improve the detection performance and applied the measurement to actual steel structures as a field test. The ELECT system to detect corrosion near the ground comprised a magnetic sensor probe, a sensor circuit, a multiple-frequency alternative current (AC) current source for the induction coil, a lock-in detector, and a personal computer. The magnetic probe consisted of two anisotropic magnetic resistance sensors, induction coils to generate eddy currents in the steel structures, and the cancellation coil to reduce the directly coupled magnetic field exposure. The magnetic spectrum curve, which can be used to trace the obtained magnetic field vectors (intensity and phase), was acquired by multiple-frequency exposure. The reduction in steel thickness was further estimated based on the changes in magnetic curve. The optimization of certain parameters, such as the exposure coil shape and lift-off between the sensor probe and the steel, led to improvements in the magnetic curve, which enabled sensitive detection; further, 1-mm thinning was successfully detected at a depth of 60 mm. Furthermore, the results obtained by the ELECT system at the ground surface were in good agreement with the results of the thickness measurements that were directly obtained from the structure after digging into the ground.

    Scopus

    researchmap

  • Evaluation of hardened and non- ardened regions using eddy current testing

    Kenji Sakai, Takahiro Ito, Toshihiko Kiwa, Keiji Tsukada

    Studies in Applied Electromagnetics and Mechanics   43   1 - 8   2018年

     詳細を見る

    掲載種別:研究論文(国際会議プロシーディングス)  

    © 2018 The authors and IOS Press. A steel plate having hardened and non-hardened regions in one plate is promising material in automobile field owing to its high performance. This steel plate has to be evaluated whether the non-hardened region was prepared properly at the desired position with desired hardness. However, the conventional evaluation method of hardness measurement is destructive testing and requires a long inspection time. Therefore, a reliable and fast nondestructive inspection method is required. In this study, the hardened and non-hardened regions were evaluated using an eddy current testing (ECT) to distinguish each region. The measured resistivity and permeability at each region were different and these differences were found to be caused by the crystal structure change of heat treatment. Therefore, the magnetic response between the hardened and nonhardened regions was different and this difference was correlated with the hardness of each region. These results indicate that the hardened and non-hardened regions can be distinguished using ECT.

    DOI: 10.3233/978-1-61499-836-5-1

    Scopus

    researchmap

  • Development of in situ methods for battery using a THz chemical microscope

    Kentaro Fujiwara, Yuki Akiwa, Kenji Sakai, Toshihiko Kiwa, Keiji Tsukada

    Optics InfoBase Conference Papers   Part F113-CLEOPR 2018   2018年

     詳細を見る

    掲載種別:研究論文(国際会議プロシーディングス)  

    © OSA 2018 It is important to measure the special deviation of electrochemical reactions on electrodes to improve the performance of batteries. Here, electrochemical measurement using THz chemical microscope with a sealed container was applied for measurements.

    DOI: 10.1364/cleopr.2018.tu3c.6

    Scopus

    researchmap

  • Immune assay using a micro-flow channels detected by a terahertz chemical microscopy

    Tatsuki Kamiya, Masahiro Iida, Kenji Sakai, Toshihiko Kiwa, Keiji Tsukada

    Optics InfoBase Conference Papers   Part F113-CLEOPR 2018   2018年

     詳細を見る

    掲載種別:研究論文(国際会議プロシーディングス)  

    © OSA 2018 We have developed a terahertz chemical microscopy (TCM) to visualize various types of chemical reactions. Here, a micro-flow channels were fabricated on a sensing plate, and measured time evolution of immune reactions using the TCM.

    DOI: 10.1364/cleopr.2018.tu3c.3

    Scopus

    researchmap

  • Evaluation of penetration of cosmetic liquids using terahertz time of flight method

    T. Kuroda, T. Morimoto, K. Sakai, T. Kiwa, K. Tsukada

    2018 43RD INTERNATIONAL CONFERENCE ON INFRARED, MILLIMETER, AND TERAHERTZ WAVES (IRMMW-THZ)   2018年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:IEEE  

    The terahertz time-of-flight method was applied to evaluate the the penetration speed and the depth of the skin lotion into the skin. The result suggests that the terahertz time-of-flight method is one of useful option in this field.

    Web of Science

    researchmap

  • Application of a HTS Coil with a Magnetic Sensor to Nondestructive Testing Using a Low-Frequency Magnetic Field 査読

    Yasuaki Matsunaga, Ryota Isshiki, Yuta Nakamura, Kenji Sakai, Toshihiko Kiwa, Keiji Tsukada

    IEEE Transactions on Applied Superconductivity   27 ( 4 )   2017年6月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC  

    © 2016 IEEE. Detecting corrosion at an early stage on the backside of a thick steel plate using a magnetic field is difficult because of the high permeability of steel. Therefore, we used a low-frequency magnetic field to enable the penetration of magnetic flux deep into the steel plate. According to Faraday's law, to achieve a sufficiently intense signal at low frequencies, the number of turns of a normal conducting coil must be increased. However, a high-temperature superconducting (HTS) coil has a very low resistance; thus, the shielding current of a HTS coil can flow under magnetic fields with a wide-frequency range. Although HTS coils exhibit good shielding characteristics at low frequencies, their voltage signals are very weak. To solve this problem, a magnetic sensor was used to detect the shielding current of a HTS coil. The detection unit included the HTS coil, and the magnetic sensor was optimized; moreover, the possibility of operating the magnetic sensor at the liquid nitrogen temperature (77 K) was investigated. As a demonstration of nondestructive testing using the magnetic response of the HTS coil and magnetic sensor, we measured the change in the thickness of a steel plate in which corrosion was assumed to have occurred. Consequently, we obtained a good response even with a low-frequency magnetic field when using a HTS coil with a few turns. In the thickness measurements of steel plates, thicknesses ranging from 6 to 19 mm were obtained in the frequency range of 1-5 Hz.

    DOI: 10.1109/TASC.2016.2631420

    Web of Science

    Scopus

    researchmap

  • 漏洩磁束探傷検査法を用いた鉄板内部欠陥検出法の開発 査読

    SONG Nannan, 芳賀勇太, 合田剛士, 堺健司, 紀和利彦, 塚田啓二

    電気学会マグネティックス研究会資料   MAG-16 ( 119-132.134 )   2017年4月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)  

    DOI: 10.1109/SAS.2017.7894069

    Web of Science

    Scopus

    J-GLOBAL

    researchmap

  • Novel terahertz measurements systems born in Okayama

    Toshihiko Kiwa

    Journal of the Institute of Electronics, Information and Communication Engineers   99 ( 10 )   975 - 979   2016年10月

     詳細を見る

    掲載種別:研究論文(学術雑誌)  

    Scopus

    researchmap

  • Simultaneously detection two types of ions using THz chemical microscopy 査読

    Kosuke Akimune, Yuki Okawa, Kenji Sakai, Toshihiko Kiwa, Keiji Tsukada

    2015 11th Conference on Lasers and Electro-Optics Pacific Rim, CLEO-PR 2015   3   2016年1月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:Institute of Electrical and Electronics Engineers Inc.  

    © 2015 IEEE. THz chemical microscopy has been proposed and developed to detect ions in water solutions. In this work, the change in the amplitude of THz radiation was measured when ion solutions was dropped on detection plate.

    DOI: 10.1109/CLEOPR.2015.7376395

    Scopus

    researchmap

  • A terahertz technology for label-free immune assay 査読

    Toshihiko Kiwa, Masahiro Ogawa, Kousuke Akimune, Hiroyuki Nino, Kenji Sakai, Keiji Tsukada

    2015 11th Conference on Lasers and Electro-Optics Pacific Rim, CLEO-PR 2015   3   2016年1月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:Institute of Electrical and Electronics Engineers Inc.  

    © 2015 IEEE. This paper reviews recent works of label-free immune assay using terahertz technologies, which includes a terahertz chemical microscopy. Experimental results of label-free detection of lectin-suger chain reactions were also presented.

    DOI: 10.1109/CLEOPR.2015.7376392

    Scopus

    researchmap

  • pH Measurements Of nano-liter Solutions Using THz Technology 査読

    Y. Zhou, K. Akimune, K. Hamada, K. Sakai, T. Kiwa, K. Tsukada

    SENSORS AND ELECTRONIC INSTRUMENTATION ADVANCES (SEIA)   60 - 61   2016年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:INT FREQUENCY SENSOR ASSOC-IFSA  

    A terahertz chemical microscopy (TCM) has been proposed and developed to visualize the electric potential changes of water solution on the semiconductor-based plate named 'sensing plate'. The TCM detects the change in the amplitude of THz waves from the sensing plate, which can be related to the electric potential of the water solutions on the sensing plate. Since the top surface of the sensing plate was made from the SiO2, the electric potential at the surface of the sensing plate could be change by changing the pH values of the solutions on the sensing plate. In order to detect the small amount of water solutions, micro-wells made of UV curable resin were patterned on the surface of the sensing plate with diameters range between 50 mu m to 500 mu m. Thus the solution of 16-nL were measured, which indicated that the pH measurements of nano-litter solutions could be possible using TCM.

    Web of Science

    researchmap

  • Terahertz-Time-of-Flight Method for Evaluating Cosmetic Samples Penetrating into Skin Samples 査読

    T. Arisawa, T. Morimoto, K. Sakai, T. Kiwa, K. Tsukada

    SENSORS AND ELECTRONIC INSTRUMENTATION ADVANCES (SEIA)   117 - 119   2016年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:INT FREQUENCY SENSOR ASSOC-IFSA  

    A terahertz(THz)-time-of-flight(TOF) method was carried out for in-vitro measurements of the penetration depth of cosmetic liquid into skin samples. In our group, a sensing plate, which can generate terahertz pulses, has been developed. By irradiating the back side of the sensing plate using a femto-second laser pulses, the THz pulses with the pulse width of approximately 1 ps were radiated into a free space. When the artificial skin samples were put on the sensing plate, the generated THz pulses travel in the skin samples and are reflected at the boundary between the regions where the cosmetic liquid exists and does not exist. Since traveling time of the THz pulses are generally proportional to the traveling path, the distance between the boundary and the sensing plate can be estimated by evaluating the traveling time of the THz pulses. Here, as demonstration of the developed method, the penetration of liquid into the artificial dermis made from collagen were evaluated.

    Web of Science

    researchmap

  • Application to Non-destructive Evaluation of Gas Barrier Films Using a High-speed Terahertz Time-domain Spectroscopy 査読

    Masaya Inamo, Kenji Sakai, Toshihiko Kiwa, Keiji Tsukada

    2016 PROGRESS IN ELECTROMAGNETICS RESEARCH SYMPOSIUM (PIERS)   3921 - 3921   2016年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:IEEE  

    Web of Science

    researchmap

  • Development of Terahertz Chemical Microscope for Detecting Small Molecules 査読

    Takuya Kuwana, Yuki Hanaoka, Toshihiko Kiwa, Kenji Sakai, Keiji Tsukada

    2016 PROGRESS IN ELECTROMAGNETICS RESEARCH SYMPOSIUM (PIERS)   3927 - 3927   2016年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:IEEE  

    Web of Science

    researchmap

  • Combinatorial Sensing of Catalytic Materials Using Terahertz Chemical Microscope 査読

    Yuji Hino, Yuki Kawakami, Kenji Sakai, Toshihiko Kiwa, Keiji Tsukada

    SENSORS AND ELECTRONIC INSTRUMENTATION ADVANCES (SEIA)   104 - 106   2016年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:INT FREQUENCY SENSOR ASSOC-IFSA  

    Terahertz chemical microscope (TCM) has been developed to visualize the electrical and/ or chemical potential on the 'sensing plate' as the distribution of the amplitude of THz pulses radiated from the sensing plate. In this study, the combinatorial search of membrane materials using TCM was proposed and evaluation of catalytic reactions of Pt thin film was demonstrated. Pt thin films with the thickness of 4 nm, 7 nm, 10 nm and 15 nm were fabricated on the same sensing plate. Each Pt thin film on the sensing plate was exposed to the dry air (80 % nitrogen gas and 20 % oxygen gas) and hydrogen gas (1 %) and air every three minutes, independently. The amplitudes shifts of radiated THz pulses could be related to the thickness of Pt thin films on the sensing plate. This result suggests that TCM is one of useful option for the combinatorial sensing of catalytic materials.

    Web of Science

    researchmap

  • Automatic Scanning System for Back-Side Defect of Steel Structure Using Magnetic Flux Leakage Method 査読

    Kenji Sakai, Koji Morita, Yuta Haga, Toshihiko Kiwa, Katsumi Inoue, Keiji Tsukada

    IEEE Transactions on Magnetics   51 ( 11 )   2015年11月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC  

    © 1965-2012 IEEE. An automatic nondestructive evaluation system using the magnetic-flux-leakage method was developed for detecting the back-side defects of large structures in order to realize fast detection in a wide measurement area. A magnetic field was applied to an object using a ferrite yoke with an induction coil, and the leaked magnetic flux from the object was detected by a magnetoresistive sensor. This measurement probe was fixed on an automatic scanning system. The developed automatic scanning system detected magnetic signal changes corresponding to the back-side defects of the steel plates. To demonstrate the effectiveness of the developed system, we measured the steel plate of a cargo crane, which was corroded on the back side. We found that the detected magnetic signal changed markedly in the area with corrosion, whereas only a slight magnetic signal change was detected in the area without corrosion. Therefore, the developed system is useful for detecting the back-side defects in a wide area, and can be used for screening tests.

    DOI: 10.1109/TMAG.2015.2453211

    Web of Science

    Scopus

    researchmap

  • 尿検査用集積型イオンセンサの開発 査読

    菅井良祐, 山本貴文, 堺健二, 紀和利彦, 塚田啓二

    電気学会ケミカルセンサ研究会資料   13 ( 8 )   706 - 710   2015年8月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)  

    DOI: 10.1166/sl.2015.3475

    Scopus

    J-GLOBAL

    researchmap

  • Effect of diamagnetic contribution of water on harmonics distribution in a dilute solution of iron oxide nanoparticles measured using high-T<inf>c</inf> SQUID magnetometer 査読

    Mohd Mawardi Saari, Yuya Tsukamoto, Toki Kusaka, Yuichi Ishihara, Kenji Sakai, Toshihiko Kiwa, Keiji Tsukada

    Journal of Magnetism and Magnetic Materials   394   260 - 265   2015年7月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ELSEVIER SCIENCE BV  

    © 2015 Elsevier B.V. All rights reserved. The magnetization curve of iron oxide nanoparticles in low-concentration solutions was investigated by a highly sensitive high-Tc superconducting quantum interference device (SQUID) magnetometer. The diamagnetic contribution of water that was used as the carrier liquid was observed in the measured magnetization curves in the high magnetic field region over 100 mT. The effect of the diamagnetic contribution of water on the generation of harmonics during the application of AC and DC magnetic fields was simulated on the basis of measured magnetization curves. Although the diamagnetic effect depends on concentration, a linear relation was observed between the detected harmonics and concentration in the simulated and measured results. The simulation results suggested that improvement could be expected in harmonics generation because of the diamagnetic effect when the iron concentration was lower than 72 μg/ml. The use of second harmonics with an appropriate bias of the DC magnetic field could be utilized for realization of a fast and highly sensitive detection of magnetic nanoparticles in a low-concentration solution.

    DOI: 10.1016/j.jmmm.2015.06.090

    Web of Science

    Scopus

    researchmap

  • Ion transportation of electrolytes in a flow channel mapped by an HTS SQUID scanning system 査読

    Toshihiko Kiwa, Kohei Tanaka, Shohei Kasuya, Kenji Sakai, Keiji Tsukada

    IEEE Transactions on Applied Superconductivity   25 ( 3 )   2015年6月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC  

    © 2014 IEEE. In this paper, we propose and develop a device for visualizing the magnetic field produced by ion transportation in electrolyte cells. Using 0.5 mM potassium ferricyanide (K3[Fe(CN)6]) dissolved in 0.5 M sodium sulfate (Na2SO4) as the electrolyte, the magnetic distribution was obtained using high-TC SQUID scanning performed by a planar gradiometer located above the electrolyte cell across the surface. The difference in the ion transportation path in the electrolyte cells is discussed with regard to flow channels fabricated in the electrolyte cells.

    DOI: 10.1109/TASC.2014.2382656

    Web of Science

    Scopus

    researchmap

  • Moisture content evaluation using improved high-tc squid-based rotating-sample magnetometer 査読

    Kenji Sakai, Naohiro Okamoto, Yuuta Watanabe, Mohd Mawardi Saari, Toshihiko Kiwa, Keiji Tsukada

    IEEE Transactions on Applied Superconductivity   25 ( 3 )   2015年6月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC  

    © 2002-2011 IEEE. Moisture content evaluated by magnetic signal change measured by rotating-sample magnetometer using higherature superconductor superconducting quantum interference device (HTS-SQUID) was investigated. To realize highly sensitive measurement of moisture content, an improvement in signal-to-noise (S/N) ratio of the previously developed magnetometer was examined. To increase the S/N ratio, the sample case with short width along the sample's movement direction was employed. By reducing the sample case width, the obtained magnetic signal intensity increased, and the frequency component of magnetic signal shifted toward high frequencies, leading to the low magnetic field noise range measurements. Using the improved magnetometer, the moisture content of silica gel was measured, and the magnetic signal intensity increased as the amount of water in the silica gel increased. Therefore, we propose a high-sensitivity, noncontact, and nondestructive method for moisture content evaluation using rotating-sample magnetometer.

    DOI: 10.1109/TASC.2014.2363353

    Web of Science

    Scopus

    researchmap

  • Optimization of an AC/DC High- T<inf>c</inf> SQUID magnetometer detection unit for evaluation of magnetic nanoparticles in solution 査読

    Mohd Mawardi Saari, Yuichi Ishihara, Yuya Tsukamoto, Toki Kusaka, Koji Morita, Kenji Sakai, Toshihiko Kiwa, Keiji Tsukada

    IEEE Transactions on Applied Superconductivity   25 ( 3 )   2015年6月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC  

    © 2002-2011 IEEE. We have optimized the detection unit of a previously developed AC/DC magnetometer that employs a high critical temperature superconducting quantum interference device (high- Tc SQUID). Optimization involves improvement of the usable dynamic range of the high- Tc SQUID system during excitation with an AC magnetic field using a tuned compensation coil and an increase in the DC magnetic field resolution using a secondary excitation coil. The compensation coil technique had resulted in a single and compact detection coil using one SQUID for both AC and DC magnetization measurement functions with improved sensitivity in AC measurements. The sensitivity of the improved system is demonstrated by measuring the magnetization curve and harmonics distribution of low-concentration iron oxide nanoparticles solutions. Highly sensitive evaluation of magnetic nanoparticles in solutions can be expected with the developed system.

    DOI: 10.1109/TASC.2014.2363633

    Web of Science

    Scopus

    researchmap

  • Characterization of the magnetic moment distribution in low-concentration solutions of iron oxide nanoparticles by a high- T <inf>c</inf> superconducting quantum interference device magnetometer 査読

    M. M. Saari, K. Sakai, T. Kiwa, T. Sasayama, T. Yoshida, K. Tsukada

    Journal of Applied Physics   117 ( 17 )   2015年5月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:AMER INST PHYSICS  

    © 2015 AIP Publishing LLC. We developed a highly sensitive AC/DC magnetometer using a high-temperature superconductor superconducting quantum interference device for the evaluation of magnetic nanoparticles in solutions. Using the developed system, we investigated the distribution of magnetic moments of iron oxide multi-core particles of 100 nm at various iron concentrations that are lower than 96 μg/ml by analyzing the measured magnetization curves. Singular value decomposition and non-regularized non-negative least-squares methods were used during the reconstruction of the distribution. Similar distributions were obtained for all concentrations, and the iron concentration could be determined from the measured magnetization curves. The measured harmonics upon the excitation of AC and DC magnetic fields curves agreed well with the harmonics simulated based on the reconstructed magnetization curves, implying that the magnetization curves of magnetic nanoparticles were successfully obtained as we will show in the article. We compared the magnetization curves between multi-core particles of 100 nm and 130 nm, composed of 12-nm iron oxide nanoparticles. A distinctive magnetic property between the 100 nm and 130 nm particles in low-concentration solutions was successfully characterized. The distribution characteristic of magnetic moments suggests that the net magnetic moment in a multi-core particle is affected by the size of the magnetic cores and their degree of aggregation. Exploration of magnetic properties with high sensitivity can be expected using the developed system.

    DOI: 10.1063/1.4919043

    Web of Science

    Scopus

    researchmap

  • Time of flight measurements of polymer films by a terahertz chemical microscopy

    T. Arisawa, H. Nino, K. Sakai, T. Kiwa, K. Tsukada

    Optics InfoBase Conference Papers   Part F132-JSAP 2019   2015年

     詳細を見る

    掲載種別:研究論文(国際会議プロシーディングス)  

    Scopus

    researchmap

  • Ion sensing for nano liter level solution by a terahertz chemical microscopy

    Y. Zhou, K. Akimune, K. Sakai, T. Kiwa, K. Tsukada

    Optics InfoBase Conference Papers   Part F132-JSAP 2019   2015年

     詳細を見る

    掲載種別:研究論文(国際会議プロシーディングス)  

    Scopus

    researchmap

  • Multi-ion sensing of buffer solutions using terahertz chemical microscopy 査読

    Kosuke Akimune, Yuki Okawa, Kenji Sakai, Toshihiko Kiwa, Keiji Tsukada

    Applied Physics Express   7 ( 12 )   122401   2014年12月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:IOP PUBLISHING LTD  

    © 2014 The Japan Society of Applied Physics Terahertz chemical microscopy (TCM) has been proposed and developed to visualize electric potential and/or chemical changes in water solutions. To simultaneously detect two types of ions mixed in buffer solutions, five membranes for sodium ions and four membranes for potassium ions were integrated on a sensing plate, and the selectivity to each ion was evaluated. The results suggest that TCM can be used for multi-ion sensing in mixed solutions.

    DOI: 10.7567/APEX.7.122401

    Web of Science

    Scopus

    researchmap

  • A terahertz chemical microscopy for an agar culture medium 査読

    H. Nino, A. Nakamura, K. Omura, K. Sakai, T. Kiwa, K. Tsukada

    2014 31th URSI General Assembly and Scientific Symposium, URSI GASS 2014   2014年10月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:IEEE  

    © 2014 IEEE. In the field of life science, the research trends are to visualize 'living' materials as it is, whereas most of conventional imaging methods require pre-treatments to living samples. In our group, a terahertz chemical microscope (TCM) has been proposed and developed to investigate metabolism by the cell activity. Here the agar medium, which was generally used to cultivate cells, was immobilized on the sensing plate of TCM and the concentration of the glucose in the buffer solutions on it was detected as the terahertz amplitude shift. This result suggests that the TCM can detect the glucose in the solutions and it may possible to detect the cell activity cultivated on the agar mediums.

    DOI: 10.1109/URSIGASS.2014.6930088

    Web of Science

    Scopus

    researchmap

  • Label-free detection of proteins using a terahertz chemical microscopy 査読

    M. Ogawa, A. Nakamura, K. Omura, K. Sakai, T. Kiwa, K. Tsukada

    2014 31th URSI General Assembly and Scientific Symposium, URSI GASS 2014   2014年10月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:IEEE  

    © 2014 IEEE. A terahertz chemical microscopy (TCM) has been proposed and developed to visualize the distribution of chemical reactions such as antigen-antibody reaction on the sensing plate without any labels on the analyte. The TCM utilize the semiconductor-based device named a sensing plate. The sensing plate can convert the shift of the chemical potential in the magnitude on the surface of sensing plate into the amplitude of generated terahertz (THz) in the sensing plate. Thus, it enables to get images of the potential distribution on the surface of the sensing plate as the distribution of THz amplitude. Here, we demonstrate the detection of the immune reactions between the mouse immunoglobulin G (IgG) and the anti-mouse immunoglobulin G (anti-IgG). IgG was immobilized on the sensing plate and reacted with anti-IgG in the solutions with various concentrations. We also fabricated the sample wells on the sensing plate and quantitative evaluation of immune reactions were demonstrated with the anti-IgG concentration of between 5 nM and 100 nM. As a result, the change in the THz amplitude during the reaction showed the proportional relation with the concentration of reacted anti-IgG.

    DOI: 10.1109/URSIGASS.2014.6930087

    Web of Science

    Scopus

    researchmap

  • Multi-ion sensing in solutions by a terahertz chemical microscopy 査読

    K. Akimune, Y. Okawa, T. Hagiwara, K. Sakai, T. Kiwa, K. Tsukada

    2014 31th URSI General Assembly and Scientific Symposium, URSI GASS 2014   2014年10月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:IEEE  

    © 2014 IEEE. A terahertz chemical microscopy (TCM) has been proposed and developed in order to visualize the chemical potential changes in the water solution. In this paper, ion sensing in solutions, as an application of terahertz chemical microscopy, are introduced, and we observed the variation of amplitude of THz wave. In TCM, we detect the change in the amplitude of radiated THz wave from a THz sensing plate. The sensing plate is that the amplitude of radiated THz wave changes when chemical reactions are undergo on the THz sensing plate. We immobilized ion sensitive membranes, which can take the certain ion, on the surface of SiO2side of THz sensing plate. We dropped the sodium solution of 10-4M and 10-1M. The amplitude of radiated THz wave as the concentration of 10-1M was large in magnitude than the concentration of 10-4M where the ion sensitive membrane was immobilized. We can also visualize the concentration of ions to get image. From these results, we can detect ions in solution using TCM.

    DOI: 10.1109/URSIGASS.2014.6930079

    Web of Science

    Scopus

    researchmap

  • Visualization of ion transportation in an electrolyte using an HTS-SQUID gradiometer 査読

    Toshihiko Kiwa, Shinogo Miyazaki, Mohd M. Saari, Kenji Sakai, Akira Tsukamoto, Seiji Adachi, Tsunehiro Hato, Keiichi Tanabe, Keiji Tsukada

    Physica C: Superconductivity and its Applications   504   84 - 87   2014年9月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ELSEVIER SCIENCE BV  

    Direct detection of magnetic fields generated by the ion currents in electrolytic cells was performed and the ion currents were mapped during a cyclic voltammetry experiment. A high-Tc superconducting quantum interference device (SQUID) gradiometer with ramp-edge Josephson junctions was used as the detector and thus the first derivative of the magnetic field along the electrolytic cell surface was obtained. The electric potential vs. the reference electrode was measured between -0.3 V and 0.8 V and the hysteresis signals caused by the redox reactions of the electrolyte were observed. The vector component of the ion current during cyclic voltammetry was mapped along the electrolytic cell. As a demonstration of visualization of ion transportation, the magnetic signal was also measured at various positions above the electrolytic cell surface. © 2014 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.physc.2014.04.024

    Web of Science

    Scopus

    researchmap

  • Ultrathin-film hydrogen gas sensor with nanostructurally modified surface 査読

    Keiji Tsukada, Shuzo Takeichi, Kenji Sakai, Toshihiko Kiwa

    Japanese Journal of Applied Physics   53 ( 7 )   2014年7月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:IOP PUBLISHING LTD  

    The change in electrical resistance of Pt thin films on glass substrates upon exposure to hydrogen gas at room temperature was studied. The effect was detectible only for film thicknesses of less than 40 nm, and increased with decreasing thickness. Samples were also produced with a Ti film inserted between the Pt film and the glass substrate as an adhesive layer. Although the Ti film did not react with the hydrogen gas, its presence reduced the resistance change effect because it acted as a parallel resistance. To overcome this problem, the surface of the glass substrate was nanostructurally modified using porous SiO2, which led to a larger resistance change ratio. To improve the recovery time, heating by pulsed current injection was carried out. A structure consisting of Pt (5nm)/Ti (3 nm)/porous SiO2/glass was found to show a clear response to hydrogen concentrations down to about 100 ppm at room temperature. © 2014 The Japan Society of Applied Physics.

    DOI: 10.7567/JJAP.53.076701

    Web of Science

    Scopus

    researchmap

  • Magnetic susceptibility and magnetic resonance measurements of the moisture content and hydration condition of a magnetic mixture material 査読

    K. Tsukada, T. Kusaka, M. M. Saari, R. Takagi, K. Sakai, T. Kiwa, Y. Bito

    Journal of Applied Physics   115 ( 17 )   2014年5月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:AMER INST PHYSICS  

    We developed a magnetic measurement method to measure the moisture content and hydration condition of mortar as a magnetic mixture material. Mortar is a mixture of Portland cement, sand, and water, and these materials exhibit different magnetic properties. The magnetization-magnetic field curves of these components and of mortars with different moisture contents were measured, using a specially developed high-temperature-superconductor superconducting quantum interference device. Using the differences in magnetic characteristics, the moisture content of mortar was measured at the ferromagnetic saturation region over 250 mT. A correlation between magnetic susceptibility and moisture content was successfully established. After Portland cement and water are mixed, hydration begins. At the early stage of the hydration/gel, magnetization strength increased over time. To investigate the magnetization change, we measured the distribution between bound and free water in the mortar in the early stage by magnetic resonance imaging (MRI). The MRI results suggest that the amount of free water in mortar correlates with the change in magnetic susceptibility. © 2014 AIP Publishing LLC.

    DOI: 10.1063/1.4852075

    Web of Science

    Scopus

    researchmap

  • HTS-SQUIDを用いたAC/DC複合型小型磁化率計 査読

    高木竜輝, SAARI Mohd Mawardi, 堺健司, 紀和利彦, 塚田啓二

    電気学会論文誌 A   134 ( 6 )   369 - 374   2014年

     詳細を見る

    記述言語:日本語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.1541/ieejfms.134.369

    Scopus

    J-GLOBAL

    researchmap

  • DC current distribution mapping system of the solar panels using a HTS-SQUID gradiometer 査読

    Shingo Miyazaki, Syohei Kasuya, Mohd Mawardi Saari, Kenji Sakai, Toshihiko Kiwa, Akira Tsukamoto, Seiji Adachi, Keiichi Tanabe, Keiji Tsukada

    Journal of Physics: Conference Series   507 ( PART 4 )   2014年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:IOP PUBLISHING LTD  

    Solar panels are expected to play a major role as a source of sustainable energy. In order to evaluate solar panels, non-destructive tests, such as defect inspections and response property evaluations, are necessary. We developed a DC current distribution mapping system of the solar panels using a High Critical Temperature Superconductor Superconducting Quantum Interference Device (HTS-SQUID) gradiometer with ramp edge type Josephson junctions. Two independent components of the magnetic fields perpendicular to the panel surface (∂Bz/∂x, ∂Bz/∂y) were detected. The direct current of the solar panel is visualized by calculating the composition of the two signal components, the phase angle, and mapping the DC current vector. The developed system can evaluate the uniformity of DC current distributions precisely and may be applicable for defect detection of solar panels. © Published under licence by IOP Publishing Ltd.

    DOI: 10.1088/1742-6596/507/4/042026

    Web of Science

    Scopus

    researchmap

  • Development of integrated AC-DC magnetometer using high-T<inf>c</inf> SQUID for magnetic properties evaluation of magnetic nanoparticles in solution 査読

    Mohd Mawardi Saari, Ryuki Takagi, Toki Kusaka, Yuichi Ishihara, Yuya Tsukamoto, Kenji Sakai, Toshihiko Kiwa, Keiji Tsukada

    Journal of Physics: Conference Series   507 ( PART 4 )   2014年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:IOP PUBLISHING LTD  

    We developed an integrated AC-DC magnetometer using a high critical temperature superconducting quantum interference device (high-Tc SQUID) to evaluate the static and dynamic magnetic properties of magnetic nanoparticles (MNPs) in solution. The flux-transformer method consisted of first-order planar and axial differential coils that were constructed for static and dynamic magnetization measurements, respectively. Vibrating-sample and harmonic detection techniques were used to reduce interference from excitation magnetic fields in the static and dynamic magnetization measurements, respectively. Static and dynamic magnetization measurements were performed on commercially available iron oxide nanoparticles in diluted solutions. The magnetic responses increased with the increase in concentration of the solutions in both measurement results. The magnetization curves showed that the diamagnetic signal due to the carrier liquid of the iron oxide nanoparticles existed in a dilute solution. Biasing with a proper DC magnetic field in the dynamic magnetization measurement resulted in improved signals of the second and third harmonics. Therefore, highly sensitive magnetic characterizations of MNPs utilizing the static and dynamic magnetization measurement are possible via the developed system. © Published under licence by IOP Publishing Ltd.

    DOI: 10.1088/1742-6596/507/4/042035

    Web of Science

    Scopus

    researchmap

  • パルス電流印加ゲート構成によるFET水素センサの応答特性の高速化 査読

    奥井貴博, 牛田祐貴, 武市修蔵, 堺健司, 紀和利彦, 塚田啓二

    電気学会論文誌 E   134 ( 8 )   264 - 269   2014年

     詳細を見る

    記述言語:日本語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.1541/ieejsmas.134.264

    Scopus

    J-GLOBAL

    researchmap

  • Catalytic reactions of the fuel cells visualized by THz chemical microscope

    T. Kusaka, K. Koiso, K. Sakai, T. Kiwa, K. Tsukada

    Optics InfoBase Conference Papers   2014年

     詳細を見る

    掲載種別:研究論文(国際会議プロシーディングス)  

    A terahertz chemical microscope has been developed to visualize the electric potential shift of the catalytic electrodes in fuel cells. The potential shift due to the catalytic reactions of the supplied gases could be visualized. © 2014 OSA.

    DOI: 10.1364/lacsea.2014.ltu3d.6

    Scopus

    researchmap

  • Magnetic nondestructive test for resistance spot welds using magnetic flux penetration and eddy current methods 査読

    Keiji Tsukada, Kousuke Miyake, Daichi Harada, Kenji Sakai, Toshihiko Kiwa

    Journal of Nondestructive Evaluation   32 ( 3 )   286 - 293   2013年9月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:SPRINGER/PLENUM PUBLISHERS  

    Resistance spot welding technologies are widely used in industry. A highly reliable monitoring method is needed to effectively weld and create a robust structure. We developed a combined technique using magnetic flux penetration and an eddy current test (ECT). The magnetic measuring system consists of a pair of magnetic probes having an induction coil and detection coil, a lock-in amplifier, a current source, and a personal computer. The magnetic flux penetration through both surfaces at the weld was measured at low frequency. The ECT was performed at each surface with multiple frequencies. The magnetic flux penetration method showed good correlation with the destructive shear test because of the change in permeability due to the formation of the nugget. The ECT method reflected the depth profile of the nugget and was effective for determining a defective product. © 2013 Springer Science+Business Media New York.

    DOI: 10.1007/s10921-013-0181-0

    Web of Science

    Scopus

    researchmap

  • Development of a compact magnetometer with an AC/DC magnetic field using HTS-SQUID 査読

    Ryuki Takagi, Mohd Mawardi Saari, Kenji Sakai, Toshihiko Kiwa, Keiji Tsukada

    2013 IEEE 14th InternationalSuperconductive Electronics Conference, ISEC 2013   2013年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:IEEE  

    Measuring the magnetic susceptibility of a material enable us to specify composition of the material. We have reported on development of a compact moving-sample magnetometer using high-temperature superconducting quantum interference device (HTS-SQUID). However, this magnetometer needs long time when we have to measure many samples. In order to solve this problem, we developed a compact magnetometer to analyze quantitative magnetic characteristics by our rapid measurement system using AC/DC functions. The optimal mounting position of pickup coils for the AC magnetic field measurement was optimized. The performance of the AC magnetic field measurement system was evaluated by measuring harmonic components of the AC magnetic response from a dispersion of iron oxide in styrene resin, when AC/DC magnetic field is applied. Using this system, the sample composition of ferromagnetic and diamagnetic substances can be evaluated from the mixed sample by measuring the harmonic components of the magnetic responses. © 2013 IEEE.

    DOI: 10.1109/ISEC.2013.6604309

    Web of Science

    Scopus

    researchmap

  • Label free immune assay using terahertz chemical microscope 査読

    Toshihiko Kiwa, Akira Tenma, Shinji Takahashi, Kenji Sakai, Keiji Tsukada

    Sensors and Actuators, B: Chemical   187   8 - 11   2013年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ELSEVIER SCIENCE SA  

    A terahertz chemical microscope (TCM) has been proposed and developed to visualize the distribution of the antibody-antigen bindings on the silicon based sensing plate without any labels and/or markers on the antibody. The sensing plate can emit the terahertz pulses by femtosecond laser pulses and the amplitude of the terahertz pulses can be related to the chemical or electric potential of the sensing plate surface at where the laser pulses are irradiated. Thus the potential distribution can be visualized as the map of the terahertz pulses amplitude. As the first demonstration of the label free immune assay, the mouse immunoglobulin G (IgG) was immobilized on the half part of the sensing plate and the mouse anti-IgG was combined with the IgG. The terahertz pulses were enhanced at where anti-IgG was combined with IgG on the sensing plate and the distributions of the IgG and anti-IgG bindings on the sensing plate were clearly seen as the TCM images. The amplitude of terahertz pulses as a function of the concentration of anti-IgG was also investigated. © 2012 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.snb.2012.08.051

    Web of Science

    Scopus

    researchmap

  • Visualization of the catalytic reactions in the fuel cells using THz chemical microscope 査読

    T. Hagiwara, T. Kusaka, T. Kiwa, K. Sakai, K. Tsukada

    International Conference on Infrared, Millimeter, and Terahertz Waves, IRMMW-THz   2013年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)  

    THz Chemical Microscope can visualize the work function shift of the catalytic electrodes in fuel cells. We observed the variation of the terahertz wave intensity at the cathode and anode under fuel cell operation. From this result, TCM is a valuable tool for investigation and evaluation of the catalytic electrode and electrolyte in fuel cells. © 2013 IEEE.

    DOI: 10.1109/IRMMW-THz.2013.6665916

    Scopus

    researchmap

  • Evaluation of work function of the catalytic electrode in the fuel cells 査読

    Toshihiko Kiwa, Takafumi Hagiwara, Tetsuya Kusaka, Kenji Sakai, Keiji Tsukada

    Pacific Rim Conference on Lasers and Electro-Optics, CLEO - Technical Digest   2013年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:IEEE  

    The fuel cell was fabricated on the sensing plate and the catalytic reaction of the electrode was measured using terahertz chemical microscope. Change in the amplitude of THz at the catalytic cathode and anode could be observed. © 2013 IEEE.

    DOI: 10.1109/CLEOPR.2013.6600102

    Web of Science

    Scopus

    researchmap

  • Hydrogen gas response of meta-materials made from the catalytic metal 査読

    Takuya Sono, Mitsuhiro Shinomiya, Kenji Sakai, Toshihiko Kiwa, Keiji Tsukada

    Pacific Rim Conference on Lasers and Electro-Optics, CLEO - Technical Digest   2013年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:IEEE  

    The meta-materials with a catalytic metal are fabricated on Si substrate and the hydrogen gas reaction in the THz transmittance was measured. The results suggest that two different catalytic mechanisms contribute the change in transmittance in different frequency region. © 2013 IEEE.

    DOI: 10.1109/CLEOPR.2013.6600256

    Web of Science

    Scopus

    researchmap

  • Nondestructive inspection of SiGe films using laser terahertz emission microscopy 査読

    Akihiro Nakamura, Ken Omura, Kenji Sakai, Toshihiko Kiwa, Keiji Tsukada

    Pacific Rim Conference on Lasers and Electro-Optics, CLEO - Technical Digest   2013年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:IEEE  

    Laser terahertz emission microscopy was applied to investigate the SiGe film on the Si substrate. In this study, as the initial experiment to apply LTEM to non-destructive evaluation of the strained SiGe films, the THz emission properties of the strained-SiGe were measured. © 2013 IEEE.

    DOI: 10.1109/CLEOPR.2013.6600524

    Web of Science

    Scopus

    researchmap

  • Terahertz properties from the surface of strained SiGe on Si multilayered structure 査読

    K. Omura, A. Nakamura, T. Kiwa, Y. Yamashita, K. Sakai, K. Tsukada

    International Conference on Infrared, Millimeter, and Terahertz Waves, IRMMW-THz   2013年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)  

    A Large-scale integration (LSI) has been improved by scaling contraction. Strained Si has been proposed as a higher carrier mobility than usual. We have evaluated the strained SiGe wafer by LTEM, which is a method of analyzing to detect THz waves generated by fs laser irradiated into the sample. © 2013 IEEE.

    DOI: 10.1109/IRMMW-THz.2013.6665819

    Scopus

    researchmap

  • 新型構造ナトリウムイオンセンサの開発および応答解析 査読

    小森達也, 山本貴文, 小田和代, 堺健司, 紀和利彦, 塚田啓二

    電気学会論文誌 E   133 ( 7 )   309 - 313   2013年

     詳細を見る

    記述言語:日本語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.1541/ieejsmas.133.309

    Scopus

    J-GLOBAL

    researchmap

  • HTS-SQUIDを用いたサンプル回転方式小型磁化率計の高感度化 査読

    濱崎大地, 岡本直大, SAARI Mohd Mawardi, 堺健司, 紀和利彦, 塚田啓二

    電気学会論文誌 A   134 ( 5 )   347 - 351   2013年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)  

    DOI: 10.1109/ISEC.2013.6604306

    Web of Science

    Scopus

    J-GLOBAL

    researchmap

  • Development of a compact DC magnetometer using HTS-SQUID and a rotating sample 査読

    K. Sakai, M. M. Saari, T. Kiwa, A. Tsukamoto, S. Adachi, K. Tanabe, A. Kandori, K. Tsukada

    Superconductor Science and Technology   25 ( 4 )   2012年4月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:IOP PUBLISHING LTD  

    We developed a compact DC magnetometer using a high-temperature superconductor (HTS) superconducting quantum interference device (SQUID) to measure very weak magnetic signals from samples such as paramagnetic and diamagnetic materials. The samples were rotated in the DC magnetic field that was detected by a normal conductive pick-up coil. The detected signal was transferred to an input coil that was inductively coupled to the SQUID. To clarify the basic characteristics of this system, the magnetic signal from a magnetic material was measured by varying the sample position and rotation speed. Then, the magnetic signal from pure water was measured under the optimized condition and a very weak magnetic signal from pure water was successfully detected. Therefore, the developed system could be applied to various non-destructive evaluation systems. © 2012 IOP Publishing Ltd.

    DOI: 10.1088/0953-2048/25/4/045005

    Web of Science

    Scopus

    researchmap

  • Electric characteristics of a loop in which two junctions between a catalytic metal and a noncatalytic metal are under different hydrogen gas concentrations 査読

    Keiji Tsukada, Kenji Sakai, Toshihiko Kiwa

    Applied Physics Express   5 ( 3 )   2012年3月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:IOP PUBLISHING LTD  

    To investigate the localized electrochemical properties of an electrode composed of platinum (Pt), a thin-film loop containing two junctions between the catalytic metal Pt and the noncatalytic metal titanium was fabricated. When the loop was open and only one junction was exposed to 10% hydrogen in nitrogen gas, an output voltage change of about 30 nV was generated between these two junctions. The electron density change due to the equilibrium reaction of hydrogen dissociation along the part exposed to hydrogen induced a balance between the diffusion and drift caused by the electric field at both ends of the Pt film. © 2012 The Japan Society of Applied Physics.

    DOI: 10.1143/APEX.5.034102

    Web of Science

    Scopus

    researchmap

  • Silver Gate Field Effect Transistor for Oxygen Gas Sensor 査読

    Keiji Tsukada, Daisuke Kiriake, Kenji Sakai, Toshihiko Kiwa

    PROCEEDINGS OF SENSORDEVICES 2011: THE SECOND INTERNATIONAL CONFERENCE ON SENSOR DEVICE TECHNOLOGIES AND APPLICATIONS   5 - 7   2011年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:IARIA XPS PRESS  

    A silver gate field effect transistor (FET) integrated thermal controller was developed for a new type of oxygen gas sensor. It showed a threshold voltage change at a temperature as low as 80 degrees C. Oxygen response characteristics of the FET prepared with different productions of silver materials using a vacuum-evaporated membrane, printed material using silver-nanoparticles and silver epoxy were compared. The FET with a gate of silver epoxy showed the largest sensitivity of 135 mV/decade in the oxygen concentration range from 5% to 40% at 120 degrees C.

    Web of Science

    researchmap

  • Detection of back-side pit on a ferrous plate by magnetic flux leakage method with analyzing magnetic field vector 査読

    Keiji Tsukada, Mitsuteru Yoshioka, Yoshihiko Kawasaki, Toshihiko Kiwa

    NDT and E International   43 ( 4 )   323 - 328   2010年6月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ELSEVIER SCI LTD  

    We have developed a magnetic flux leakage (MFL) system using magnetic resistive (MR) sensors for detecting two dimensional magnetic field components, and an induction coil that generates low magnetic field strengths and extremely low frequencies. The signal at each scanned measurement point (i) was divided by the signal strength Mmes,i and phase αi by a lock-in amplifier. Using the strength Mmes,i and phase αi, we calculated the imaginary part of the signal using the common phase β. By optimization of the common phase β to the imaginary part, the analyzed scanning data curve was shown to be effective in estimating the size (depth and diameter) of back-side pits on a ferrous plate. Comparing the two dimensional magnetic field components of leakage, the imaginary part of the y-component parallel to the induced magnetic field was found to be suitable for detecting the back-side pits. © 2010 Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.ndteint.2010.01.004

    Web of Science

    Scopus

    researchmap

  • Chemical imaging of μ-TAS using terahertz chemical microscope 査読

    Toshihiko Kiwa, Yuji Minami, Yusuke Kondo, Yohei Hashimoto, Iwao Kawayama, Masayoshi Tonouchi, Keiji Tsukada

    IRMMW-THz 2010 - 35th International Conference on Infrared, Millimeter, and Terahertz Waves, Conference Guide   2010年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:IEEE  

    A terahertz chemical microscope (TCM) has been carried out to visualize the chemical potential distribution in μ-TAS. Since the TCM can detect the chemical potential at exactly where the femtosecond laser was irradiated, the spatial resolution less than 1μm, which is limited by the wavelength of the femtosecond laser, can be achieved. The μ-TAS was fabricated on the sensing chip and the distribution of chemical potential was successfully visualized using TCM. © 2010 IEEE.

    DOI: 10.1109/ICIMW.2010.5613018

    Web of Science

    Scopus

    researchmap

  • EXTREME LOW FREQUENCY MAGNETIC IMAGING METHOD FOR DETECTION OF DEFECT INSIDE WELDING PARTS OF IRON PLATE 査読

    Keiji Tsukada, Teruki Hasegawa, Mituteru Yoshioka, Toshihiko Kiwa, Katsumi Inoue

    10TH EUROPEAN CONFERENCE ON NON-DESTRUCTIVE TESTING 2010 (ECNDT), VOLS 1-5   82 - 93   2010年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:INT COMMITTEE NON-DESTRUCTIVE TESTING  

    Web of Science

    researchmap

  • Hydrogen gas diffusion imaging using multiple FET type gas sensors 査読

    T. Kiwa, T. Yamaguchi, K. Tsubota, W. Naruyama, H. Yamada, K. Tsukada

    International Journal of Advanced Mechatronic Systems   2 ( 4 )   219 - 224   2010年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    Imaging of hydrogen gas concentrations were demonstrated using arrayed sensors system in the cylindrical diffusion tank-shaped simulator. The field effect transistor type hydrogen sensors with platinum gate electrode were used. The sensitivity of the sensors was around -34.1 mV/dec. and the response time was 1.2 sec. in average. By applying a sensor drive circuit to each sensor, the diffusion processes of the hydrogen gas were successfully obtained in time domain and two different processes were demonstrated using 100% hydrogen gas. These results indicate that real-time monitoring of the hydrogen gas distribution can be possible. Additionally, the calibration method of the acquired data was proposed. © 2010 Inderscience Enterprises Ltd.

    DOI: 10.1504/IJAMechS.2010.033594

    Scopus

    researchmap

  • Control of terahertz wave front using arrayed terahertz emission device 査読

    K. Beppu, T. Sugimoto, T. Kiwa, K. Tsukada

    IRMMW-THz 2010 - 35th International Conference on Infrared, Millimeter, and Terahertz Waves, Conference Guide   2010年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:IEEE  

    Arrayed THz emission device was proposed to control the wave front of THz. The simulation results indicated the THz wave front can be tilted by changing the emission pattern of the device. The 4×4 arrayed device was fabricated and the emission pattern was successfully controlled by the bias voltages.

    DOI: 10.1109/ICIMW.2010.5612739

    Web of Science

    Scopus

    researchmap

  • A Novel Ion Sensor Without a Reference Electrode 査読

    Keiji Tsukada, Fumiyuki Kobayashi, Toyotaka Inoue, Toshihiko Kiwa

    SENSOR LETTERS   7 ( 6 )   1163 - 1166   2009年12月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:AMER SCIENTIFIC PUBLISHERS  

    We developed an ion sensor with a novel structure that does not require a reference electrode. The structure consists of a double electrode comprising an outer electrode with a hole and an inner electrode, a polymeric ion-selective membrane, and the sensor body. The ion sensitivity of a potassium ion sensor, where the hole of the outer electrode was the same size as the inner electrode, was 55 mV/decade. The sensor exhibited increased sensitivity according to the increment of the hole size The sensitivity was also dependent on the thickness of the outer membrane covering the outer electrode These phenomena were examined using a membrane potential gradient simulation

    DOI: 10.1166/sl.2009.1240

    Web of Science

    researchmap

  • Dual gate FET hydrogen gas sensor 査読

    K. Tsukada, M. Kariya, T. Yamaguchi, T. Kiwa, H. Yamada, T. Maehara, T. Yamamoto, S. Kunitsugu

    Proceedings of IEEE Sensors   517 - 519   2009年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:IEEE  

    We developed a dual gate FET hydrogen gas sensor for application to hydrogen vehicles. The dual gate FET hydrogen sensor was integrated with Pt-gate FET to detect hydrogen and Ti-gate FET as the reference sensor in the same Si chip. Ti-gate FET has the same structure as Pt-FET except for the gate metal. The Pt-FET showed good response to hydrogen gas above 10 ppm in air, while the Ti-FET did not show any response to hydrogen gas. The differential output voltage between the Pt-FET and the Ti-FET was stable in the range of room temperature to 80° C because of the same temperature dependence of the I-V characteristic. ©2009 IEEE.

    DOI: 10.1109/ICSENS.2009.5398290

    Web of Science

    Scopus

    researchmap

  • Hydrogen gas diffusion imaging using multiple FET type gas sensors 査読

    T. Kiwa, T. Yamaguchi, K. Tsubota, W. Naruyama, H. Yamada, K. Tsukada

    Proceedings of the 2009 IEEE International Conference on Networking, Sensing and Control, ICNSC 2009   282 - 286   2009年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:IEEE  

    Imaging of hydrogen gas concentrations were demonstrated using arrayed sensors system in the cylindrical diffusion tank-shaped simulator. The field effect transistor type hydrogen sensors with platinum gate electrode were used. The sensitivity of the sensors was around -34.1 mV/dec. and the response time was 1.2 sec. in average. By applying a sensor drive circuit to each sensor, the diffusion processes of the hydrogen gas were successfully obtained in time domain and two different processes were demonstrated using 100% hydrogen gas. Theseresults indicate that real-time monitoring of the hydrogen gas distribution can be possible. Additionally, the calibration method of the acquired data was proposed. © 2009 IEEE.

    DOI: 10.1109/ICNSC.2009.4919287

    Web of Science

    Scopus

    researchmap

  • Evaluation of the catalytic metal for the hydrogen sensor using terahertz chemical microscope 査読

    Takeshi Sugimoto, Yosuke Kondo, Toshihiko Kiwa, Iwao Kawayama, Masayoshi Tonouchi, Keiji Tsukada

    34th International Conference on Infrared, Millimeter, and Terahertz Waves, IRMMW-THz 2009   411 - +   2009年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:IEEE  

    To develop the hydrogen sensor, the chemical potential due to the catalytic reaction of the metals are required to evaluate. The platinum and titanium layered electrode on the insulator/semiconductor layered device are fabricated as the test chip. The catalytic reaction of platinum and hydrogen gas were successfully visualized. © 2009 IEEE.

    DOI: 10.1109/ICIMW.2009.5325729

    Web of Science

    Scopus

    researchmap

  • Redox reaction imaging using THz chemical microscope 査読

    Y. Minami, T. Kiwa, I. Kawayama, M. Tonouchi, K. Tsukada

    34th International Conference on Infrared, Millimeter, and Terahertz Waves, IRMMW-THz 2009   272 - 274   2009年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:IEEE  

    Terahertz chemical microscope was carried out to visualize the distribution of the redox reaction of the immobilized-enzyme. The urease films with the spot size of 3, 2, 1 mm in diameter were immobilized on a SiO2/Si/ Sapphire layered device and the laser-excited terahertz radiation from the Si layer was observed, which can be related to the chemical potential shift of the SiO2 surface. The redox reaction between the urease and the urea solution was successfully measured. © 2009 IEEE.

    DOI: 10.1109/ICIMW.2009.5324691

    Web of Science

    Scopus

    researchmap

  • Laser terahertz emission microscope 査読

    Hironaru Murakami, Naotsugu Uchida, Ryotaro Inoue, Sunmi Kim, Toshihiko Kiwa, Masayoshi Tonouchi

    Proceedings of the IEEE   95 ( 8 )   1646 - 1657   2007年8月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC  

    Developments of laser terahertz (THz) emission microscope (LTEM) systems are reviewed. Femtosecond lasers can excite the THz wave emission from various electronic materials, such as semiconductors, high-temperature superconductors, manganites, multiferroic oxides, etc., due to ultrafast current modulation. Limiting the topic to semiconductors, the current modulation is realized by acceleration or deceleration of photoexcited carriers due to the local electric field extrinsically or intrinsically induced at the laser illumination spot. Thus, LTEM has a potential to visualize the local electric field distribution and photoresponse without any contacts or damages. We have ever constructed prototype free-space type and scanning fiber-probe (SFP) type LTEM systems with transmission or reflection mode. The system performance of the SFP-LTEM has been greatly improved compared with that for the prototype one. The spatial resolution of the SFP-LTEM system has a minimum spatial resolution less than 3 mum , which is defined by the laser beam diameter. The compact SFP-LTEM system, in particular the reflection system, has the potential to be utilized for wide applications as well as various materials. In this review paper, we introduce the details of the LTEM systems and example applications for the evaluation of electric field distribution in integrated circuits and supercurrent distribution in high-temperature superconductors. © 2006 IEEE.

    DOI: 10.1109/JPROC.2007.898829

    Web of Science

    Scopus

    researchmap

  • Terahertz emission from catalytic-metal/semiconductor interface of hydrogen sensors

    T. Kiwa, K. Tsukada, M. Suzuki, M. Tonouchi, S. Migitaka, K. Yokosawa

    Optics InfoBase Conference Papers   2005年

     詳細を見る

    掲載種別:研究論文(国際会議プロシーディングス)  

    Terahertz emission properties of catalytic-metal/semiconductor structures under hydrogen gas were investigated for non-contact and non-destructive test of hydrogen sensors. The peak amplitude of terahertz from the samples decreases with increasing the hydrogen concentration.©2005 Optical Society of America.

    DOI: 10.1364/otst.2005.tud7

    Scopus

    researchmap

  • Pulse current response of high-T <inf>c</inf> superconducting vortex flow transistors 査読

    Y. Doda, T. Kiwa, I. Kawayama, H. Murakamia, M. Tonouchi

    Chinese Journal of Physics   42 ( 4 II )   458 - 462   2004年8月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:PHYSICAL SOC REPUBLIC CHINA  

    The properties of superconducting vortex flow transistor (SVFT), which consist of a vortex flow channel and a control line for applying a magnetic field, are diagnosed by using a current pulses train method. The time-domain waveforms of the vortex flow voltage along the channel were measure using the current pulses train with the pulse width of 5 ms as input signals. The fast response of the flow voltage suggests that the heating effect is negligible and the effect of the magnetic field generated by the control line was dominant in our measurement. The vortex flow speed was estimated from the ratio of the flux flow voltage to the control current, and was found to be 8.6×10 4 m/s. We also estimated the pinning energy E p from the vortex flow speed, and found that the value of E p is around 8.6 meV for our device, which can be easily excited by a conventional Ti:sapphire femtosecond laser.

    Web of Science

    Scopus

    researchmap

  • Photomixer with superconductor detector for sub-THz generator 査読

    Toshihiko Kiwa, Masayoshi Tonouchi

    Proceedings of SPIE - The International Society for Optical Engineering   5354   121 - 128   2004年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:SPIE-INT SOC OPTICAL ENGINEERING  

    A new type of optical-microwave conversion system has been proposed as high-stabilized oscillators and optical interfaces for superconducing circuits. The photomixer with heterodyne mixing of two lasers was applied to generate the electromagnetic waves and high-TC grain boundary Josephson junction detector was used to monitor the frequency of electromagnetic waves in real time. The current-voltage properties of Josephson junction detector were examined and the system operation up to 50 GHz was demonstrated. We also described in detail the two types of optical-microwave conversion system.

    DOI: 10.1117/12.528892

    Web of Science

    Scopus

    researchmap

  • Non-contact measurement of MOSFET with zero bias voltage using the Laser-THz emission microscope 査読

    Masatsugu Yamashita, Toshihiko Kiwa, Masayoshi Tonouchi, Kiyoshi Nikawa, Chiko Otani, Kodo Kawase

    Conference Digest of the 2004 Joint 29th International Conference on Infrared and Millimeter Waves and 12th International Conference on Terahertz Electronics   515 - 516   2004年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:IEEE  

    For inspecting electrical failures in large-scale integration (LSI) circuits, we developed the laser-THz emission microscope (LTEM), which records the map of THz emission amplitude in a sample upon excitation with fs laser pulses. We successfully observed the THz emission image of MOSFETs embedded in a test element group under zero bias voltage. This result suggests that the LTEM can be used not only for the defect localization in LSI failure analysis but also as in-line inspection and monitoring. © 2004 IEEE.

    Web of Science

    Scopus

    researchmap

  • Evaluation of spatial resolution in Laser-Terahertz emission microscope for inspecting electric faults in integrated circuits 査読

    Masatsugu Yamashita, Toshihiko Kiwa, Masayoshi Tonouchi, Kodo Kawase

    Proceedings of SPIE - The International Society for Optical Engineering   5354   104 - 111   2004年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:SPIE-INT SOC OPTICAL ENGINEERING  

    We have proposed and demonstrated a nondestructive and non-contact inspection method for electrical faults using laser-Terahertz (THz) emission microscopy (LTEM). By measuring the position dependence of the amplitude of the THz emission from integrated circuits (IC) excited with femtosecond (fs) laser pulses, it is possible to investigate the electrical faults in IC. By improving the spatial resolution of the system, we successfully observed the THz emission image of a microprocessor on standby mode. The LTEM system has a spatial resolution about 3μm and it can localize electrically defective sites in the chip to within a ten square microns.

    DOI: 10.1117/12.528833

    Web of Science

    Scopus

    researchmap

  • Magnetic flux letters visualized by a laser-terahertz emission microscope 査読

    Masayoshi Tonouchi, Toshihiko Kiwa, Takashi Fukui, Hironaru Murakami

    Proceedings of SPIE - The International Society for Optical Engineering   5354   112 - 120   2004年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:SPIE-INT SOC OPTICAL ENGINEERING  

    Magnetic flux letters are visualized by a laser terahertz emission microscope (LTEM). LTEM excites terahertz (THz) radiation from electronics materials with a femtosecond laser and maps the amplitude of the THz waves while scanning laser beam on the sample. Magnetic flux letters written in high-Tc superconductors are successfully imaged without destroying them.

    DOI: 10.1117/12.529026

    Web of Science

    Scopus

    researchmap

  • “開拓”進むテラヘルツ領域 集積回路評価用レーザーテラヘルツ放射顕微鏡の開発 査読

    山下将嗣, 紀和利彦, 斗内政吉, 大谷知行, 川瀬晃道

    光学   34 ( 9 )   29 - 30   2004年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)  

    DOI: 10.1109/IMFEDK.2004.1566392

    Scopus

    J-GLOBAL

    researchmap

  • Optical-microwave converter: Superconductor/photomixer hybrid system 査読

    Toshihiko Kiwa, Masayoshi Tonouchi

    IEEE MTT-S International Microwave Symposium Digest   2   1363 - 1366   2003年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:IEEE  

    A new type of optical-microwave converter utilizing a photomixer and a high-Tc Josephson junction detector has been developed. The frequency difference of two laser beams has been observed in the characteristic of the high-Tc Josephson junction detector. The measured response of the detector for the microwave generated by photomixing two lasers suggests that the system can work as a highly sensitive wavelength meter with accuracy of ±3.5 pm. The system operation up to 20 GHz was also demonstrated by changing the wavelength of two laser beams.

    Web of Science

    Scopus

    researchmap

  • A new wavemeter for C-band using Josephson junction

    T. Kiwa, M. Tonouchi

    OSA Trends in Optics and Photonics Series   88   1603 - 1604   2003年

     詳細を見る

    掲載種別:研究論文(国際会議プロシーディングス)  

    A new system that utilized photomixer and Josephson junction microwave detector has been proposed and developed. The results suggested that our system can be used as one of high precision wavemeters. © 2002 Optical Society of America.

    Scopus

    researchmap

  • Terahertz radiation from amorphous GaAs thin film photoconductive switches 査読

    T. Kiwa, I. Kawashima, M. Morimoto, H. Saijyo, S. Nashima, M. Yamashita, M. Tonouchi, M. Hangyo

    CLEO/Pacific Rim 1999 - Pacific Rim Conference on Lasers and Electro-Optics   2   447 - 448   1999年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:Institute of Electrical and Electronics Engineers Inc.  

    © 1999 IEEE. Low-temperature grown GaAs (LT-GaAs) has been studied as a potential material for microwave-photonic devices such as a terahertz (THz) radiation emitter. Since the preparation of the LT-GaAs generally requires a post annealing process at around 600 °C, these has been limited to be a small number of the applications combined with other materials. In the present work, we study the photoresponse of amorphous (α-) GaAs prepared at between room temperature and 250 °C by femtosecond time-domain reflection pump-probe measurements and photo-induced THz emission measurements.

    DOI: 10.1109/CLEOPR.1999.811513

    Scopus

    researchmap

▼全件表示

書籍等出版物

  • テラヘルツ波新産業 (新材料・新素材シリーズ)

    シーエムシー出版  2011年 

     詳細を見る

MISC

  • 磁気計測における自動車の環境雑音の影響評価

    齊藤大介, 小嵐愛子, 林実, 若林俊輝, 堺健司, 紀和利彦, 塚田啓二

    電気学会全国大会講演論文集(CD-ROM)   2020   2020年

     詳細を見る

  • 光触媒のサブピコ秒電位変化の計測実現

    紀和利彦

    岡山工学振興会ニュース   ( 117 )   2020年

     詳細を見る

  • Pt超薄膜型水素センサの駆動電流の最適化による風の外乱影響低減

    合田悠斗, 小部寛斗, 堺健司, 紀和利彦, 近藤健二, 高橋琢哉, 上田尚宏, 塚田啓二

    電気学会論文誌 E   140 ( 4 )   92 - 96   2020年

  • グラジオメータ用いた不飽和漏洩磁束法によるロングレールの非破壊検査

    林実, 堺健司, 紀和利彦, 塚田啓二

    電気学会全国大会講演論文集(CD-ROM)   2020   2020年

     詳細を見る

  • 漏洩磁束探傷法を用いた異形鉄筋の腐食検出

    川上太聖, 林実, 堺健司, 紀和利彦, 塚田啓二

    電磁力関連のダイナミクスシンポジウム講演論文集   32nd   2020年

     詳細を見る

  • 渦電流探傷法による鋳造品の欠陥評価

    志垣一也, 紀和利彦, 塚田啓二, 堺健司

    電磁力関連のダイナミクスシンポジウム講演論文集   32nd   2020年

     詳細を見る

  • 磁気ナノ粒子の固相/液相変化による周波数磁場応答特性変化

    平松文太, 山下慶, 神野克也, 綱島健太, 藤元佳与, 堺健司, 紀和利彦, 塚田啓二

    電気学会全国大会講演論文集(CD-ROM)   2020   2020年

     詳細を見る

  • テラヘルツ波を用いた皮膚への化粧水浸透評価手法の開発

    紀和利彦

    コスメトロジー研究報告   28   2020年

     詳細を見る

  • 超伝導デバイスを用いた高感度磁気計測システムの開発と応用

    塚田啓二, 堺健司, 紀和利彦

    応用物理学会春季学術講演会講演予稿集(CD-ROM)   67th   2020年

     詳細を見る

  • アレルギー検査に向けたテラヘルツ波ケミカル顕微鏡のヒスタミン測定

    佐藤孝祐, 飯田将弘, 葭田勇一, 堺健司, 紀和利彦, 塚田啓二

    応用物理学会春季学術講演会講演予稿集(CD-ROM)   67th   2020年

     詳細を見る

  • 血清濃度変化による磁気ナノ粒子の磁気特性の影響

    山下慶, 平松文太, 神野克也, 綱島健太, 藤元佳与, 堺健司, 紀和利彦, 塚田啓二, SAARI Mohd Mawardi Bin

    電気学会全国大会講演論文集(CD-ROM)   2020   2020年

     詳細を見る

  • 渦電流探傷法を用いた鋼板端部における焼入れ状態の非破壊評価

    堺健司, 紀和利彦, 塚田啓二

    日本非破壊検査協会秋季講演大会講演概要集   2019   2019年

     詳細を見る

  • テラヘルツ波ケミカル顕微鏡を用いた生体関連物質評価法 査読

    紀和利彦, 神谷樹, 飯田将弘, 井上博文, 堺健司, 豊岡伸一, 塚田啓二

    日本レーザー医学会誌   39 ( 4 )   341 - 346   2019年

     詳細を見る

  • レーザー励起テラヘルツ波を用いた二次電池電極非破壊検査装置の開発

    紀和利彦, 寺西貴志

    山陽技術雑誌   67   2019年

     詳細を見る

  • テラヘルツ波ケミカル顕微鏡による微小量溶液中イオン濃度計測

    紀和利彦, 前野佑貴, 眞鼻敦也, AHMED Feroz, 堺健司, 塚田啓二

    分析化学討論会講演要旨集   79th   2019年

     詳細を見る

  • テラヘルツ波ケミカル顕微鏡を用いたin-situリチウムイオン電池評価法

    紀和利彦, 秋和佑季, 寺西貴志, 秋和佑季, 能勢秀俊, 小林正樹, 堺健司, 塚田啓二

    シンポジウムテラヘルツ科学の最先端講演要旨集   2019   2019年

     詳細を見る

  • 磁気免疫検査装置における溶媒による磁気ナノ粒子の磁気特性への影響

    平松文太, 神野克也, 綱島健太, 藤元佳与, 堺健司, 紀和利彦, SAARI Mohd Mawardi Bin, 塚田啓二

    電気・情報関連学会中国支部連合大会講演論文集(CD-ROM)   70th   2019年

     詳細を見る

  • 光触媒のサブピコ秒電位変化の計測実現

    紀和利彦

    岡山工学振興会ニュース   ( 115 )   2019年

     詳細を見る

  • 極低周波渦電流探傷法による地際腐食検出性能の向上

    若林俊輝, 富岡卓哉, 堺健司, 紀和利彦, 塚田啓二

    表面探傷シンポジウム講演論文集   22nd   2019年

     詳細を見る

  • 不飽和交流漏洩磁束法による鉄鋼構造物の溶接部欠陥信号の判別

    林実, 斉藤大介, 中村喜浩, 堺健司, 紀和利彦, 塚田啓二

    表面探傷シンポジウム講演論文集   22nd   2019年

     詳細を見る

  • 微小金属欠陥が検出可能な磁気センサプローブの開発

    小部寛斗, 合田悠斗, 神原匠, 堺健司, 紀和利彦, 塚田啓二

    電気・情報関連学会中国支部連合大会講演論文集(CD-ROM)   70th   2019年

     詳細を見る

  • 極低周波渦電流探傷法を用いた腐食度の高い鉄鋼構造物の減肉測定

    齊藤大介, 林実, 若林俊輝, 富岡卓哉, 堺健司, 紀和利彦, 塚田啓二

    日本非破壊検査協会秋季講演大会講演概要集   2019   2019年

     詳細を見る

  • SQUID磁気免疫検査における磁気を用いた抗原抗体反応の時間短縮

    平松文太, 神野克也, 綱島健太, 竹内駿, 藤元佳与, 堺健司, 紀和利彦, 塚田啓二

    電気学会全国大会講演論文集(CD-ROM)   2019   2019年

     詳細を見る

  • テラヘルツ波を用いた二次電池電極の非破壊検査

    紀和利彦, 藤原健太郎, 秋和佑希, 吉川祐未, 寺西貴志, 能勢秀俊, 小林正樹, 堺健司, 塚田啓二

    レーザー研究   47 ( 1 )   2019年

     詳細を見る

  • 極低周波渦電流探傷法による錆で覆われた鋼材の板厚評価

    富岡卓哉, 若林俊輝, 堺健司, 紀和利彦, 塚田啓二, 武藤秀人, 藤野陽三

    電気学会全国大会講演論文集(CD-ROM)   2019   2019年

     詳細を見る

  • 磁気計測によるアルミニウム合金と鋼の溶接接合の評価

    小部寛斗, 合田悠斗, 平田哲朗, 堺健司, 紀和利彦, 塚田啓二

    電気学会全国大会講演論文集(CD-ROM)   2019   2019年

     詳細を見る

  • 不飽和交流漏洩磁束法を用いた鉄鋼構造物の亀裂形状の推定

    齊藤大介, 林実, 中村喜浩, 堺健司, 紀和利彦, 塚田啓二

    電気学会全国大会講演論文集(CD-ROM)   2019   2019年

     詳細を見る

  • 超伝導コイルと磁気センサを用いた高リフトオフ非破壊検査システムの開発

    平田哲朗, 合田悠斗, 堺健司, 紀和利彦, 安達成司, 塚本晃, 田辺圭一, 塚田啓二

    MAGDAコンファレンス講演論文集   27th   2018年

     詳細を見る

  • 極低周波渦電流探傷法によるチタン下の鋼材の板厚評価

    富岡卓哉, 合田剛士, 堺健司, 紀和利彦, 塚田啓二

    電気学会全国大会講演論文集(CD-ROM)   2018   2018年

     詳細を見る

  • TMRセンサを用いた鉄鋼材の亀裂検出

    林実, 中村喜浩, 堺健司, 紀和利彦, 塚田啓二

    表面探傷シンポジウム講演論文集   21st   2018年

     詳細を見る

  • 極低周波渦電流探傷法による鉄鋼構造物の地際腐食検査

    若林俊輝, 富岡卓哉, 堺健司, 紀和利彦, 塚田啓二

    表面探傷シンポジウム講演論文集   21st   2018年

     詳細を見る

  • SQUID磁気免疫検査装置におけるC反応性タンパクの高感度検出

    綱島健太, 神野克也, 竹内駿, 福田行治郎, 藤元佳与, 柴倉美砂子, 堺健司, 紀和利彦, 圓福敬二, 塚田啓二

    電磁力関連のダイナミクスシンポジウム講演論文集   30th   2018年

     詳細を見る

  • エネルギー輸送の違いから見たカーボンナノチューブの通電加熱の効果

    中條大樹, 井上寛隆, 黒田泰平, 森本大我, 林拓磨, 徳永知春, 池田直, 横谷尚睦, 藤森和博, 羽田真毅, 西川亘, 山下善文, 紀和利彦, 林靖彦

    応用物理学会春季学術講演会講演予稿集(CD-ROM)   65th   2018年

     詳細を見る

  • テラヘルツ波飛行時間法を用いた皮膚組織への化粧水浸透評価

    黒田泰平, 森本大我, 堺健司, 紀和利彦, 塚田啓二

    応用物理学会春季学術講演会講演予稿集(CD-ROM)   65th   2018年

     詳細を見る

  • グラジオメータを用いた不飽和交流磁束漏洩法によるき裂検出性能

    中村喜浩, 林実, 堺健司, 紀和利彦, 塚田啓二

    電気学会全国大会講演論文集(CD-ROM)   2018   2018年

     詳細を見る

  • SQUID磁気免疫検査装置における磁気マーカを用いたアビジン-ビオチン結合反応の基礎評価

    神野克也, 綱島健太, 竹内駿, 藤元佳与, 堺健司, 紀和利彦, 圓福敬二, 塚田啓二

    電磁力関連のダイナミクスシンポジウム講演論文集   30th   2018年

     詳細を見る

  • 超電導薄膜フォーカス板を用いた交流駆動法による磁気抵抗素子の高感度化

    合田悠斗, 平田哲朗, 堺健司, 紀和利彦, 塚田啓二

    電磁力関連のダイナミクスシンポジウム講演論文集   30th   2018年

     詳細を見る

  • テラヘルツ技術の生体関連試料への応用

    紀和利彦

    オレオサイエンス   18 ( 9 )   2018年

     詳細を見る

  • 不飽和交流漏洩磁束法による鉄鋼構造物の亀裂検出と表示方法

    林実, 齊藤大介, 中村喜浩, 堺健司, 紀和利彦, 塚田啓二

    電気・情報関連学会中国支部連合大会講演論文集(CD-ROM)   69th   2018年

     詳細を見る

  • 2次微分検出コイルを用いた鉄鋼構造物の高リフトオフき裂検査法の開発

    合田悠斗, 平田哲朗, 堺健司, 紀和利彦, 塚本晃, 田辺圭一, 塚田啓二

    日本非破壊検査協会秋季講演大会講演概要集   2018   2018年

     詳細を見る

  • 磁気ナノ粒子を用いたCRPの磁気免疫分析方法

    竹内駿, 神野克也, 綱島健太, 藤元佳与, 堺健司, 紀和利彦, 塚田啓二, 圓福敬二

    低温工学・超電導学会講演概要集   96th   2018年

     詳細を見る

  • 超伝導コイルと磁気センサを用いた非破壊検査用広周波数帯域磁場検出器の開発

    平田哲朗, 合田悠斗, 堺健司, 紀和利彦, 安達成司, 塚本晃, 田辺圭一, 塚田啓二

    低温工学・超電導学会講演概要集   96th   2018年

     詳細を見る

  • トンネル磁気抵抗センサを用いた金属材の微小欠陥の検出

    神原匠, 堺健司, 紀和利彦, 塚田啓二, 鈴木雄太

    日本磁気学会学術講演概要集   42nd   2018年

     詳細を見る

  • マルチチャンネル磁気抵抗センサを用いた鉄鋼構造物の亀裂検出

    林実, 中村喜浩, 堺健司, 紀和利彦, 塚田啓二

    日本磁気学会学術講演概要集   42nd   2018年

     詳細を見る

  • HTS-SQUIDを用いた磁場計測装置による局所領域電気化学インピーダンスの評価

    堺健司, 紀和利彦, 塚田啓二

    応用物理学会秋季学術講演会講演予稿集(CD-ROM)   79th   2018年

     詳細を見る

  • Detection of inner cracks in thick steel plates using non-saturated AC magnetic flux leakage testing with a magnetic resistance gradiometer

    K. Tsukada, Y. Majima, Y. Nakamura, T. Yasugi, K. Sakai, T. Kiwa

    2017 IEEE International Magnetics Conference, INTERMAG 2017   53 ( 11 )   2553 - 2558   2017年8月

     詳細を見る

    記述言語:英語   出版者・発行元:IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC  

    © 2017 IEEE. In order to ensure the safety of social and industrial infrastructure, such as roads, bridges, dams, and chemical plants, accurate and easy inspection methods are in high demand.

    DOI: 10.1109/INTMAG.2017.8007857

    Web of Science

    Scopus

    researchmap

  • Magnetic AC Impedance Analysis Method Using High-Tc SQUID Based Magnetic Measurement System

    Kenji Sakai, Tsubasa Kizu, Toshihiko Kiwa, Keiji Tsukada

    IEEE Transactions on Applied Superconductivity   27 ( 4 )   274 - 282   2017年6月

     詳細を見る

    記述言語:英語   出版者・発行元:IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC  

    © 2016 IEEE. A new ac impedance analysis method that uses magnetic measurements was demonstrated. The magnetic field generated from the current flowing in the sample was detected by changing the frequency of the applied voltage. To detect the generated small magnetic field, a high-temperature superconductor superconducting quantum interference device (HTS-SQUID) based magnetic measurement system was developed. The developed system could detect the magnetic field without a change in the intensity and phase in the frequency range of 1 Hz to 10 kHz. In this frequency range, the spectrum correlated with the ac impedance of the electric circuit was obtained by measuring the magnetic field from the current in the circuit. Moreover, dye-sensitized solar cells with counter electrodes of different catalysis materials were prepared, and the magnetic field from the solar cell was measured. The Cole-Cole plot of the magnetic field correlated with the ac impedance measured by a conventional method, and the difference in the shape of Cole-Cole plot was explained using the equivalent circuit analysis of the dye-sensitized solar cell. Therefore, it was clarified that is possible to obtain the spectrum correlated with ac impedance using magnetic measurements.

    DOI: 10.1109/TASC.2016.2631426

    Web of Science

    Scopus

    researchmap

  • High-Resolution Laser-Assisted Magnetic Nanoparticle Imaging Using a High-T<inf>C</inf> SQUID Magnetometer

    Toshihiko Kiwa, Koji Morita, Yasuaki Matsunaga, Mohd Mawardi Saari, Kenji Sakai, Keiji Tsukada

    IEEE Transactions on Applied Superconductivity   27 ( 4 )   1108 - 1114   2017年6月

     詳細を見る

    記述言語:英語   出版者・発行元:IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC  

    © 2017 IEEE. A new type of magnetic nanoparticle imaging (MPI) system has been proposed and developed. The spatial resolution of MPI systems is generally determined and limited by the size of the magnetic sensors used and the magnetic properties of the nanoparticles detected. Here, high-resolution imaging of magnetic particles was realized by combining the MPI system with a high-TC SQUID magnetometer and laser scanning system. The spatial resolution of this system was not determined by the properties of the magnetic nanoparticles but was determined by the laser spot size focused on samples. Thus, the higher spatial resolution imparted by conventional MPI systems could be expected. As a demonstration of the imaging system, two cylindrical containers filled with magnetic particles solutions were fabricated and measured. Although the containers were spaced only 2 mm apart, they could be clearly distinguished by the obtained signals. A knife-edge analysis was also applied to the obtained signals, and the spatial resolution of our system was estimated to be approximately 0.9 mm.

    DOI: 10.1109/TASC.2017.2656118

    Web of Science

    Scopus

    researchmap

  • Magnetic characteristics measurements of ethanol-water mixtures using a hybrid-type high-temperature superconducting quantum-interference device magnetometer

    Keiji Tsukada, Yasuaki Matsunaga, Ryota Isshiki, Yuta Nakamura, Kenji Sakai, Toshihiko Kiwa

    AIP Advances   7 ( 5 )   158 - 162   2017年5月

     詳細を見る

    記述言語:英語   出版者・発行元:AMER INST PHYSICS  

    © 2017 Author(s). The magnetic characteristics of ethanol-water mixtures were investigated using our newly developed hybrid-type magnetometer based on a high-temperature superconducting quantum-interference device. The magnetization (M-H) curves of ethanol-water mixtures show good diamagnetic characteristics. The magnetic moments of the mixture show ethanol concentration dependence. However, the variation in magnetic moment differs from the characteristics expected by considering the magnetic moment ratio between water and ethanol, and volume-reduction rate. It showed two decrement regions separated at approximately 50-60% concentration values. It is also observed that the concentration dependence of the magnetic moment measured using the sample vibration method under a uniform magnetic field and that by the sample rotation method showed slightly different characteristics. These anomalies are attributed to the formation of clustered structures in the mixture.

    DOI: 10.1063/1.4973950

    Web of Science

    Scopus

    researchmap

  • Absolute-magnetic-field measurement using nanogranular in-gap magnetic sensor with second-harmonic and liquid-nitrogen-temperature operation

    Keiji Tsukada, Takuya Yasugi, Yatsuse Majima, Kenji Sakai, Toshihiko Kiwa

    AIP Advances   7 ( 5 )   1257 - 1264   2017年5月

     詳細を見る

    記述言語:英語   出版者・発行元:AMER INST PHYSICS  

    © 2017 Author(s). To detect the absolute magnetic field, such as the earth’s magnetic field, a linear magnetic response, a zero point, and thermal stability are required. We thus propose an operating method and sensor probe consisting of a nanogranular in-gap magnetic sensor (GIGS), an operational amplifier integrated circuit, and a modulation coil. The sensor probe was operated in second-harmonic mode at a liquid-nitrogen (Liq. N2) temperature. When an AC magnetic field was applied to GIGS, the second-harmonic signal was generated and modulated by the outer magnetic field to be measured. After lock-in detection, the modulated output signal showed good linearity and a zero point. Moreover, higher sensitivity and low noise with low thermal fluctuation was obtained by the cooling at Liq. N2 temperature.

    DOI: 10.1063/1.4978217

    Web of Science

    Scopus

    researchmap

  • Magnetic method for measuring moisture content using diamagnetic characteristics of water

    Tsukada Keiji, Matsunaga Yasuaki, Nakamura Yuta, Isshiki Ryota, Fujimoto Kayo, Sakai Kenji, Kiwa Toshihiko

    Measurement Science and Technology   28 ( 1 )   3477 - 3487   2017年1月

     詳細を見る

    記述言語:英語   出版者・発行元:IOP PUBLISHING LTD  

    © 2016 IOP Publishing Ltd. Moisture content measurements of rice kernels and soil are important for agriculture. Therefore, in this study, a new measurement method using the diamagnetic characteristics of water was developed for measurements of the moisture content of rice kernels and soil. The magnetic characteristics of the samples were determined using a magnetometer developed by us based on a superconducting quantum interference device. Because of the diamagnetic characteristics of water, the susceptibility of rice kernels became more negative with increasing moisture content. In the case of soil, which is a mixture of diamagnetic and ferromagnetic materials, a second-harmonic detection method using AC with DC bias magnetic field was applied to reduce the influence of the ferromagnetic signal. The intensity of the second-harmonic signal of a soil was determined to be proportional to its moisture content.

    DOI: 10.1088/1361-6501/28/1/014010

    Web of Science

    Scopus

    researchmap

  • 不飽和交流漏洩磁束探傷法の開発と鋼板のき裂検出応用

    馬島八世, 八杉拓也, 中村喜浩, 堺健司, 紀和利彦, 塚田啓二

    表面探傷シンポジウム講演論文集   20th   2017年

     詳細を見る

  • HTS-SQUID磁気測定装置を用いたエタノール水溶液の磁気特性評価

    中村勇太, 松永恭暁, 一色良太, 堺健司, 紀和利彦, 塚田啓二

    応用物理学会春季学術講演会講演予稿集(CD-ROM)   64th   2017年

     詳細を見る

  • 多重周波数印加磁場を用いた極低周波渦電流探傷検査法による鋼板裏面欠陥検出

    合田剛士, 芳賀勇太, 富岡卓哉, 堺健司, 紀和利彦, 塚田啓二

    電気学会全国大会講演論文集(CD-ROM)   2017   2017年

     詳細を見る

  • 交流変調を用いたTMRセンサの駆動法

    中村喜浩, 八杉拓也, 馬島八世, 堺健司, 紀和利彦, 塚田啓二

    電気学会全国大会講演論文集(CD-ROM)   2017   2017年

     詳細を見る

  • テラヘルツ波飛行時間測定法による鳥皮膚組織への化粧液浸透評価(II)

    森本大我, 有澤翼, 堺健司, 紀和利彦, 塚田啓二

    応用物理学会春季学術講演会講演予稿集(CD-ROM)   64th   2017年

     詳細を見る

  • テラヘルツ波ケミカル顕微鏡を用いた電極評価法の検討

    藤原健太郎, 川上祐輝, 日野佑次, 堺健司, 紀和利彦, 塚田啓二

    表面探傷シンポジウム講演論文集   20th   2017年

     詳細を見る

  • Pt超薄膜を用いたブリッジ型水素センサの開発

    天野薫, 古川遼, 井並祥太, 堺健司, 紀和利彦, 塚田啓二

    電気学会全国大会講演論文集(CD-ROM)   2017   2017年

     詳細を見る

  • HTS-SQUID磁気計測装置を用いた磁気ナノ粒子水溶液の溶媒粘度による磁気特性変化評価

    一色良太, 中村勇太, 松永恭暁, 堺健司, 紀和利彦, 塚田啓二

    応用物理学会春季学術講演会講演予稿集(CD-ROM)   64th   2017年

     詳細を見る

  • HTS-SQUIDを用いた電流が作る磁場の周波数特性測定と交流インピーダンスとの相関性

    木津翼, 堺健司, 紀和利彦, 塚田啓二

    応用物理学会春季学術講演会講演予稿集(CD-ROM)   64th   2017年

     詳細を見る

  • 高温超伝導SQUIDを用いた磁気計測による電気化学インピーダンスの推定

    堺健司, 木津翼, 紀和利彦, 塚田啓二

    電磁力関連のダイナミクスシンポジウム講演論文集   29th   2017年

     詳細を見る

  • 不飽和交流磁束漏洩法(USAC-MFL)による鉄板裏面き裂の検出

    中村喜浩, 富岡卓哉, 馬島八世, 合田剛士, 堺健司, 紀和利彦, 塚田啓二

    電磁力関連のダイナミクスシンポジウム講演論文集   29th   2017年

     詳細を見る

  • 極低周波渦電流探傷法の高速化

    富岡卓哉, 合田剛士, 堺健司, 紀和利彦, 塚田啓二

    電磁力関連のダイナミクスシンポジウム講演論文集   29th   2017年

     詳細を見る

  • 低周波磁場を用いた酸化膜付き鋼板の焼入れ状態評価

    堺健司, 伊藤嵩展, 紀和利彦, 塚田啓二

    表面探傷シンポジウム講演論文集   20th   2017年

     詳細を見る

  • 磁気スペクトル解析を用いた極低周波渦電流探傷法による腐食鋼構造物の板厚検査

    富岡卓哉, 合田剛士, 芳賀勇太, 堺健司, 紀和利彦, 塚田啓二

    表面探傷シンポジウム講演論文集   20th   2017年

     詳細を見る

  • 超伝導薄膜フォーカス板を用いた磁気抵抗素子の応答特性

    平田哲朗, 中村喜浩, 馬島八世, 天野薫, 堺健司, 紀和利彦, 塚田啓二

    低温工学・超電導学会講演概要集   94th   2017年

     詳細を見る

  • 磁気ナノ粒子の溶媒による磁気的挙動変化の高感度測定

    竹内駿, 平田哲朗, 一色良太, 中村勇太, 藤元佳与, 堺健司, 紀和利彦, 塚田啓二

    応用物理・物理系学会中国四国支部合同学術講演会講演予稿集   2017   2017年

     詳細を見る

  • 極低周波渦電流探傷法によるチタンライニング下の鋼材の板厚評価

    富岡卓哉, 合田剛士, 堺健司, 紀和利彦, 塚田啓二

    電気・情報関連学会中国支部連合大会講演論文集(CD-ROM)   68th   2017年

     詳細を見る

  • 不飽和交流磁束漏洩法によるき裂検出性能

    中村喜浩, 馬島八世, SONG NANNAN, 堺健司, 紀和利彦, 塚田啓二

    日本非破壊検査協会秋季講演大会講演概要集   2017   2017年

     詳細を見る

  • テラヘルツ波ケミカル顕微鏡を用いた電気化学イメージングシステムの開発

    藤原健太郎, 川上祐輝, 堺健司, 紀和利彦, 塚田啓二

    応用物理学会秋季学術講演会講演予稿集(CD-ROM)   78th   2017年

     詳細を見る

  • HTS-SQUIDを用いた磁気ナノ粒子水溶液の異なる溶媒による磁気特性変化の高感度解析

    一色良太, 中村勇太, 竹内駿, 平田哲朗, 藤元佳与, 堺健司, 紀和利彦, 塚田啓二

    応用物理学会秋季学術講演会講演予稿集(CD-ROM)   78th   2017年

     詳細を見る

  • 超伝導薄膜フォーカス板を用いた磁気抵抗素子の応答特性

    平田哲朗, 中村喜浩, 馬島八世, 天野薫, 堺健司, 紀和利彦, 塚田啓二

    応用物理学会秋季学術講演会講演予稿集(CD-ROM)   78th   2017年

     詳細を見る

  • 超薄膜白金を用いたブリッジ型水素センサ

    天野薫, 古川遼, 堺健司, 紀和利彦, 塚田啓二

    応用物理・物理系学会中国四国支部合同学術講演会講演予稿集   2017   2017年

     詳細を見る

  • HTS-SQUID磁気特性計測装置の反磁性サンプル回転計測法の高感度化

    中村勇太, 竹内駿, 平田哲郎, 一色良太, 堺健司, 紀和利彦, 塚田啓二

    電気・情報関連学会中国支部連合大会講演論文集(CD-ROM)   68th   2017年

     詳細を見る

  • HTS-SQUIDを用いたレーザーアシスト磁気ナノ粒子イメージングの基礎検討

    竹内駿, 平田哲朗, 一色良太, 中村勇太, 堺健司, 紀和利彦, 塚田啓二

    低温工学・超電導学会講演概要集   94th   2017年

     詳細を見る

  • Current distribution evaluation of dye-sensitized solar cell using HTS-SQUID-based magnetic measurement system

    Kenji Sakai, Kohei Tanaka, Toshihiko Kiwa, Keiji Tsukada

    Physica C: Superconductivity and its Applications   530   113 - 116   2016年11月

     詳細を見る

    記述言語:英語   出版者・発行元:ELSEVIER SCIENCE BV  

    © 2016 Elsevier B.V. The current flowing inside a dye-sensitized solar cell (DSSC) was measured using a high-temperature superconductor superconducting quantum interference device (HTS-SQUID)-based magnetic measurement system. Further, a new evaluation method of the DSSC, which is difficult to measure using the conventional method, was investigated to improve the characteristics of the DSSC. The tangential components of the magnetic field generated from the DSSC were measured using two HTS-SQUIDs, and the intensity and direction related to the electrical current were obtained by the measured magnetic field. The DSSCs prepared with different dyes and catalytic substances showed different current-intensity mapping. The current direction was different for the DSSC with low performance. In addition, the current flowing in the ITO layer of the ITO glass substrate was also measured and the results confirmed that it had uniform distribution. These results show that the current mapping and the direction of the electrical current depend on the internal factors of the DSSC, and the detection of the magnetic field distribution generated from it is expected to lead to its new evaluation method.

    DOI: 10.1016/j.physc.2016.04.002

    Web of Science

    Scopus

    researchmap

  • Detection of Inner Corrosion of Steel Construction Using Magnetic Resistance Sensor and Magnetic Spectroscopy Analysis

    Keiji Tsukada, Yuta Haga, Koji Morita, Nannan Song, Kenji Sakai, Toshihiko Kiwa, Weiying Cheng

    IEEE Transactions on Magnetics   52 ( 7 )   2016年7月

     詳細を見る

    記述言語:英語   出版者・発行元:IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC  

    © 2016 IEEE. The detection of the inner corrosion of steel construction, specifically backside corrosion of a steel plate, is highly demanded to maintain safety. Eddy-current testing (ECT) is widely used as a nondestructive testing and an evaluation method for detecting surface and subsurface flaws. However, the ECT is usually applied to non-ferromagnetic materials, but has difficulties when applied to ferromagnetic materials with high permeability, since the skin depth is smaller, and the signal-to-noise ratio (SNR) decreases due to magnetic flux fluctuation. In this paper, we developed a magnetic probe using an anisotropic magnetic resistance (AMR) sensor with the sensitivity of 1 nT/ Hz that can detect inner corrosion at extremely low frequency. We also developed an analysis method using magnetic spectroscopy to delete the magnetic flux fluctuation. To improve the SNR of the detected signal, a small cancellation coil around the AMR sensor canceled the applied magnetic field directly coupled to the sensor. The frequency of the applied magnetic field ranged from 1 Hz to 1 kHz. The sensor output at each frequency was lock-in detected. The weak ac magnetic field was applied to the initial permeability region of the magnetization curve. The obtained magnetic vector signal consisting of a real part and an imaginary part at each frequency was plotted as magnetic spectroscopy, and the magnetic component of the eddy current and the magnetic component of the magnetization of the steel were separated. By using the magnetic component of the eddy current, the thickness of an iron steel plate thinner than 16 mm could be measured. Moreover, the shape of the back-side corrosion was determined by scanning with the magnetic probe.

    DOI: 10.1109/TMAG.2016.2530851

    Web of Science

    Scopus

    researchmap

  • Hybrid Type HTS-SQUID Magnetometer with Vibrating and Rotating Sample

    Keiji Tsukada, Koji Morita, Yasuaki Matsunaga, Mohd Mawardi Saari, Kenji Sakai, Toshihiko Kiwa

    IEEE Transactions on Applied Superconductivity   26 ( 3 )   2016年4月

     詳細を見る

    記述言語:英語   出版者・発行元:IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC  

    © 2016 IEEE. Highly sensitive measurement of the very weak magnetic characteristics of magnetic particles in solution or of a solution itself is required for applications, such as biomedical examinations. In this paper, higher sensitivity and additional performance with relaxation measurement and harmonic signal detection were achieved by an improvement of the driving mechanism and the high-resolution electric magnet, and optimization of the superconducting quantum interference device (SQUID) detection unit. A servomotor was used for sample vibration and rotation with precise control and high speed. For detection of the M-H characteristics, the sample was vibrated under the magnetic field in the electromagnet. For measuring the relaxation of the magnetization, the sample was rotated. A first-order differential pickup coil with a normal conducting wire connected to the input coil of a higherature superconductor-SQUID was used to detect the magnetic signal from the sample. High-resolution measurement of the magnetic moment on the order of 10-11 A m2 was achieved with this system configuration. An ac magnetic field with a dc bias could then be applied to the sample for detection of the harmonic signal. The magnetic relaxation signal from the sample was measured by another of the same type of differential detection coil equipped outside of the electric magnet by rotating, instead of vibrating, the sample. The magnetization curve for a low concentration of iron nanoparticles with a superparamagnetic character in the solution was successfully measured using the developed magnetometer, and the relaxation phenomenon was also characterized.

    DOI: 10.1109/TASC.2016.2531632

    Web of Science

    Scopus

    researchmap

  • Label-free detection of low-molecular-weight samples using a terahertz chemical microscope

    Takuya Kuwana, Masahiro Ogawa, Kenji Sakai, Toshihiko Kiwa, Keiji Tsukada

    Applied Physics Express   9 ( 4 )   2016年4月

     詳細を見る

    記述言語:英語   出版者・発行元:IOP PUBLISHING LTD  

    © 2016 The Japan Society of Applied Physics. A terahertz chemical microscope (TCM) has been proposed and developed to visualize the distribution of biomolecular interactions on a sensing plate without any labels. In this study, the concanavalin A (Con A)-D-(+)-mannose (mannose) interaction was detected using the TCM with mannose applied as the analyte and Con A immobilized on the sensing plate. To demonstrate this interaction, the amplitude of terahertz pulses as a function of Con A-mannose interaction time, as well as the Con A-mannose coupling concentration, was evaluated. The results suggest that coupling kinetics may be evaluated using a TCM.

    DOI: 10.7567/APEX.9.042401

    Web of Science

    Scopus

    researchmap

  • Compact AC/DC Susceptometer Using a High-Temperature Superconducting Quantum Interference Device

    Ryuki Takagi, Mohd Mawardi Saari, Kenji Sakai, Toshihiko Kiwa, Keiji Tsukada

    Electronics and Communications in Japan   99 ( 3 )   369 - 374   2016年3月

     詳細を見る

    記述言語:英語   出版者・発行元:WILEY-BLACKWELL  

    © 2016 Wiley Periodicals, Inc. We developed a compact susceptometer employing a high-temperature superconductor (HTS) superconducting quantum interference device (SQUID) that can measure the M-H characteristics and the harmonic components induced in the ac magnetic field response from a sample. In the dc function for measuring M-H characteristics, the sample was vibrated in a dc magnetic field, and the secondary magnetic field generated from the sample was detected by a dc pickup coil. In the ac function for measuring harmonic components, the sample placed in an ac magnetic field, and the ac response was detected by an ac pickup coil. The pickup coil is connected in series with the input coil, which is inductively connected to the HTS-SQUID. A signal from the HTS-SQUID was transmitted to a lock-in amplifier and was analyzed as the intensity and phase of the measured magnetic field. In order to clarify the basic properties of the system, we measured the ac magnetic field response from a sample while varying the relative positions of the sample and the pickup coil, and the M-H characteristics while varying the dc bias magnetic field intensity. Furthermore, by analyzing the harmonic components of the ac/dc magnetic field response, the proposed system can measure magnetic field properties with high sensitivity and at high speed.

    DOI: 10.1002/ecj.11779

    Web of Science

    Scopus

    researchmap

  • Improvement of sensitivity of a compact magnetometer by using HTS-SQUID with rotating sample

    Daichi Hamasaki, Naohiro Okamoto, Mohd Mawardi Saari, Kenji Sakai, Toshihiko Kiwa, Keiji Tsukada

    Electrical Engineering in Japan (English translation of Denki Gakkai Ronbunshi)   194 ( 2 )   9 - 14   2016年1月

     詳細を見る

    記述言語:英語   出版者・発行元:WILEY  

    © 2015 Wiley Periodicals, Inc. We have improved a previously developed compact magnetometer using HTS-SQUID with a rotating sample. In the previous system, attenuation of the rotational speed had resulted in deformation of the averaged waveform signal, reducing the reproducibility of measurements. In this paper, we have used a better motor in order to decrease the attenuation of the rotational speed for precise averaging of the output signal and improvement of the signal-to-noise ratio. To improve sensitivity, we also optimized the pickup coil and compared the signal-to-noise ratio of circular and elliptical pickup coils having the same number of turns, resistance, and inductance. As a result, the signal-to-noise ratio was improved with high accuracy and the magnetometer showed a susceptibility sensitivity of 3.8× 10-9 emu.

    DOI: 10.1002/eej.22732

    Web of Science

    Scopus

    researchmap

  • Development of a Magnetic Phase Map for Analysis of the Internal Structure of a Spot Weld

    Nannan Song, Keisyu Shiga, Kenji Sakai, Toshihiko Kiwa, Keiji Tsukada

    Studies in Applied Electromagnetics and Mechanics   41 ( 41 )   302 - 311   2016年

     詳細を見る

    記述言語:英語   出版者・発行元:IOS PRESS  

    © 2016 The authors and IOS Press. All rights reserved. Resistance spot welding technologies are widely used in industry. We previously reported an analysis method for examining the strength of spot-welded parts with the eddy current test (ECT) by using a wide range of frequencies from high to low. However, liftoff has a non-negligible effect. Increasing the liftoff significantly decreases the magnetic field intensity for mapping. The magnetic field phase is not affected by changes in liftoff. The measured phase map of the magnetic field showed a good correlation with the results of the destructive shear test. In this paper, we report an analysis and imaging method for examining spot-welded parts based on the phase of a magnetic field by using a wide range of frequencies from high to low. With the magnetic phase map, the internal structure of a spot weld was visualized for easy understanding of the results of this method. Thus, this method can easily be applied to industrial production. This new method was validated through both experimental and simulation results.

    DOI: 10.3233/978-1-61499-639-2-302

    Web of Science

    Scopus

    researchmap

  • 電気化学インピーダンス法を用いた塩素イオンセンサ

    菅井良祐, 堺健司, 紀和利彦, 塚田啓二

    電気学会ケミカルセンサ研究会資料   136 ( 4 )   102 - 107   2016年

     詳細を見る

  • テラヘルツ波ケミカル顕微鏡の開発とケミカルセンサへの応用

    紀和利彦

    Chemical Sensors   32 ( 1 )   2016年

     詳細を見る

  • 特性が異なる色素増感型太陽電池のHTS-SQUIDを用いた磁場計測による電流特性分布評価

    堺健司, 木津翼, 紀和利彦, 塚田啓二

    応用物理学会秋季学術講演会講演予稿集(CD-ROM)   77th   2016年

     詳細を見る

  • 電気化学インピーダンス法を用いた塩素イオンセンサ

    菅井良祐, 堺健司, 紀和利彦, 塚田啓二

    電気学会論文誌 E   136 ( 4 )   2016年

     詳細を見る

  • 低周波磁場を用いた漏洩磁束探傷検査法による鋼板裏面の欠陥検出

    合田剛士, 芳賀勇太, SONG Nannan, 堺健司, 紀和利彦, 塚田啓二

    電気・情報関連学会中国支部連合大会講演論文集(CD-ROM)   67th   2016年

     詳細を見る

  • 焼入れによる鋼板の材料特性変化と磁気的非破壊検査法による部分非焼入れ部の判別

    堺健司, 伊藤嵩展, 紀和利彦, 塚田啓二

    日本非破壊検査協会秋季講演大会講演概要集   2016   2016年

     詳細を見る

  • 磁気ナノ粒子水溶液の磁化特性計測による粒径分布解析

    一色良太, 中村勇太, 松永恭暁, 堺健司, 紀和利彦, 塚田啓二

    応用物理・物理系学会中国四国支部合同学術講演会講演予稿集   2016   2016年

     詳細を見る

  • 白金薄膜の水素応答特性評価と水素センサへの応用

    天野薫, 古川遼, 井並祥太, 堺健司, 紀和利彦, 塚田啓二

    応用物理・物理系学会中国四国支部合同学術講演会講演予稿集   2016   2016年

     詳細を見る

  • 交流変調駆動によるTMRセンサの磁気応答特性

    八杉拓也, 馬島八世, 堺健司, 紀和利彦, 塚田啓二

    電気・情報関連学会中国支部連合大会講演論文集(CD-ROM)   67th   2016年

     詳細を見る

  • 交流変調法を用いた磁気センサ駆動の非破壊検査システムへの応用

    馬島八世, 八杉拓也, 堺健司, 紀和利彦, 塚田啓二

    電気・情報関連学会中国支部連合大会講演論文集(CD-ROM)   67th   2016年

     詳細を見る

  • 低周波磁場ベクトルスペクトルを用いた鋼板の板厚検査

    芳賀勇太, 合田剛士, 堺健司, 紀和利彦, 塚田啓二

    電気・情報関連学会中国支部連合大会講演論文集(CD-ROM)   67th   2016年

     詳細を見る

  • 条件が異なる焼入れ部の判別に向けた鋼板の焼入れ温度と磁場応答の関係

    伊藤嵩展, 堺健司, 紀和利彦, 塚田啓二

    電気・情報関連学会中国支部連合大会講演論文集(CD-ROM)   67th   2016年

     詳細を見る

  • インピーダンス法を用いた塩素センサ用Ag/AgCl電極の評価

    天野薫, 菅井良祐, 堺健司, 紀和利彦, 塚田啓二

    電気学会全国大会講演論文集(CD-ROM)   2016   2016年

     詳細を見る

  • 渦電流分布の可視化による表面下欠陥位置及び形状の推定

    馬島八世, 八杉拓也, 堺健司, 紀和利彦, 塚田啓二

    表面探傷シンポジウム講演論文集   19th   2016年

     詳細を見る

  • 地方創生,中国地方を元気に!4.[岡山発]テラヘルツ計測システム開発プロジェクト

    紀和利彦

    電子情報通信学会誌   99 ( 10 )   2016年

     詳細を見る

  • 低周波渦電流探傷法を用いた金属内部欠陥検出法の開発

    SONG Nannan, 馬島八世, 八杉拓也, 堺健司, 紀和利彦, 塚田啓二

    日本磁気学会学術講演概要集   40th   2016年

     詳細を見る

  • 交流変調を用いたTMR磁気センサの駆動

    馬島八世, 八杉拓也, 堺健司, 紀和利彦, 塚田啓二

    日本磁気学会学術講演概要集   40th   2016年

     詳細を見る

  • テラヘルツ波飛行時間測定法による鳥皮膚組織への化粧液浸透評価

    有澤翼, 森本大我, 堺健司, 紀和利彦, 塚田啓二

    応用物理学会秋季学術講演会講演予稿集(CD-ROM)   77th   2016年

     詳細を見る

  • 磁気検査法による鋼材の疲労度評価に向けた材料特性評価と漏洩磁束分布との相関性

    堺健司, 紀和利彦, 塚田啓二

    表面探傷シンポジウム講演論文集   19th   2016年

     詳細を見る

  • 低周波磁場スペクトルを用いた渦電流探傷検査法による鋼板の板厚評価

    合田剛士, 芳賀勇太, 堺健司, 紀和利彦, 塚田啓二

    表面探傷シンポジウム講演論文集   19th   2016年

     詳細を見る

  • テラヘルツ波ケミカル顕微鏡を用いた電池電極反応分布計測

    紀和利彦, 堺健司, 塚田啓二

    光アライアンス   27 ( 8 )   2016年

     詳細を見る

  • テラヘルツ波ケミカル顕微鏡を用いた微少量溶液pH計測

    濱田輝, 秋宗広祐, ZHOU Y., 紀和利彦, 堺健二, 塚田啓二

    応用物理学会春季学術講演会講演予稿集(CD-ROM)   63rd   2016年

     詳細を見る

  • 超薄膜水素センサの安定性の改善

    古川遼, 井並祥太, 菅井良祐, 堺健司, 紀和利彦, 塚田啓二

    電気学会全国大会講演論文集(CD-ROM)   2016   2016年

     詳細を見る

  • 交流変調によるMRセンサの駆動法

    八杉拓也, 志賀啓秀, 馬島八世, 堺健司, 紀和利彦, 塚田啓二

    電気学会全国大会講演論文集(CD-ROM)   2016   2016年

     詳細を見る

  • TiNを用いたPt超薄膜水素センサの熱的安定性改善

    井並祥太, 古川遼, 堺健司, 紀和利彦, 塚田啓二

    応用物理学会春季学術講演会講演予稿集(CD-ROM)   63rd   2016年

     詳細を見る

  • 高温超伝導コイルと一体化した磁気センサの非破壊検査応用

    松永恭暁, 森田洪爾, 堺健司, 紀和利彦, 塚田啓二

    応用物理学会春季学術講演会講演予稿集(CD-ROM)   63rd   2016年

     詳細を見る

  • HTS-SQUIDと近赤外光を用いたMPIシステムによる皮膚下MNP検出の検討

    森田洪爾, 松永恭暁, 堺健司, 紀和利彦, 塚田啓二

    応用物理学会春季学術講演会講演予稿集(CD-ROM)   63rd   2016年

     詳細を見る

  • 低周波磁場ベクトルスペクトルによる腐食鋼板の厚み測定

    芳賀勇太, 森田洪爾, 合田剛士, 伊藤嵩展, 堺健司, 紀和利彦, 塚田啓二

    電気学会全国大会講演論文集(CD-ROM)   2016   2016年

     詳細を見る

  • HTS-SQUIDを用いた高調波による砂の水分量計測

    中村勇太, 松永恭暁, 一色良太, 堺健司, 紀和利彦, 塚田啓二

    低温工学・超電導学会講演概要集   93rd   2016年

     詳細を見る

  • 磁気を用いた高感度アルコール濃度計測に向けたSN比の向上

    中村勇太, 松永恭暁, 一色良太, 堺健司, 紀和利彦, 塚田啓二

    応用物理・物理系学会中国四国支部合同学術講演会講演予稿集   2016   2016年

     詳細を見る

  • テラヘルツ波ケミカル顕微鏡を用いたレクチン糖相互作用のリアルタイム計測

    花岡侑樹, 桑名卓也, 堺健司, 紀和利彦, 塚田啓二

    応用物理・物理系学会中国四国支部合同学術講演会講演予稿集   2016   2016年

     詳細を見る

  • 超伝導コイルの磁場遮蔽特性を用いた非破壊検査

    松永恭暁, 一色良太, 中村勇太, 堺健司, 紀和利彦, 塚田啓二

    応用物理・物理系学会中国四国支部合同学術講演会講演予稿集   2016   2016年

     詳細を見る

  • 超薄膜Pt水素センサの熱的安定性の向上と水素に対する温度特性

    古川遼, 天野薫, 井並祥太, 堺健司, 紀和利彦, 塚田啓二

    応用物理・物理系学会中国四国支部合同学術講演会講演予稿集   2016   2016年

     詳細を見る

  • HTS-SQUIDを用いた磁気ナノ粒子の基礎特性評価

    一色良太, 中村勇太, 松永恭暁, 堺健司, 紀和利彦, 塚田啓二

    低温工学・超電導学会講演概要集   93rd   2016年

     詳細を見る

  • テラヘルツ波ケミカル顕微鏡を用いた電気化学反応計測法の開発

    川上祐輝, 日野佑次, 堺健司, 紀和利彦, 塚田啓二

    応用物理・物理系学会中国四国支部合同学術講演会講演予稿集   2016   2016年

     詳細を見る

  • 超高感度磁気センサを用いた電流分布計測によるモジュール型色素増感型太陽電池の評価

    木津翼, 堺健司, 紀和利彦, 塚田啓二

    応用物理・物理系学会中国四国支部合同学術講演会講演予稿集   2016   2016年

     詳細を見る

  • テラヘルツ波ケミカル顕微鏡を用いた微少量溶液pHセンサの開発

    ZHOU Y., 秋宗広祐, 濱田輝, 紀和利彦, 塚田啓二, 堺健司

    応用物理・物理系学会中国四国支部合同学術講演会講演予稿集   2016   2016年

     詳細を見る

  • Automatic scanning system for back-side defect of steel structure using magnetic flux leakage method

    K. Sakai, K. Morita, Y. Haga, T. Kiwa, K. Inoue, K. Tsukada

    2015 IEEE International Magnetics Conference, INTERMAG 2015   2015年7月

     詳細を見る

    記述言語:英語   出版者・発行元:IEEE  

    © 2015 IEEE. Non-destructive evaluation (NDE) of steel structures, such as bridge and heavy machine, is important issue to ensure their safety and reliability. However, the conventional NDE methods for these structures require long inspection time and high cost because inspections are generally performed manually. Moreover, the measurement in high-place work is also required for the inspection of huge steel structure. Therefore, the measurement system should be compact and an automatically controllable measurement system is desirable. Considering these requirement, NDE using magnetic method is suitable because the measurement system is simple and non-contact measurement are possible [1]. In this study, an automatic scanning system which can move on a wall and ceiling of steel structure was developed. In addition, to demonstrate the developed system for practical measurement, back-side defect caused by corrosions generated in steel structures of cargo crane was measured.

    DOI: 10.1109/INTMAG.2015.7157125

    Web of Science

    Scopus

    researchmap

  • Impedance Evaluation of Hydrogen Sensor Using Ultrathin Platinum Film

    Transactions of the Materials Research Society of Japan   40 ( 1 )   62 - 72   2015年

     詳細を見る

  • 低周波磁場を用いた漏洩磁束探傷検査法による強磁性体材料の板厚評価

    芳賀勇太, 森田洪爾, 堺健司, 紀和利彦, 塚田啓二

    日本非破壊検査協会秋季講演大会講演概要集   2015   2015年

     詳細を見る

  • 鋼板における部分非焼入れ部の磁気的手法を用いた非破壊検査の検討

    堺健司, 紀和利彦, 塚田啓二

    日本非破壊検査協会秋季講演大会講演概要集   2015   2015年

     詳細を見る

  • 非破壊検査に向けた高温超伝導コイルの磁場応答評価

    松永恭暁, SAARI Mohd Mawardi, 森田洪爾, 堺健司, 紀和利彦, 塚田啓二

    応用物理・物理系学会中国四国支部合同学術講演会講演予稿集   2015   2015年

     詳細を見る

  • MPIの高空間分解能化へ向けた高調波比の応用

    森田洪爾, SAARI Mohd Mawardi, 松永恭暁, 堺健司, 紀和利彦, 塚田啓二

    応用物理学会秋季学術講演会講演予稿集(CD-ROM)   76th   2015年

     詳細を見る

  • HTS-SQUIDと複数の検出コイルを用いた試料回転型磁気応答計測システムの開発

    渡部裕太, SAARI Mohd Mawardi, 堺健司, 紀和利彦, 塚田啓二

    応用物理学会秋季学術講演会講演予稿集(CD-ROM)   76th   2015年

     詳細を見る

  • HTS-SQUIDグラジオメーターを用いた磁気計測システムによる色素増感型太陽電池の評価

    堺健司, 田中洸平, SAARI Mohd Mawardi, 紀和利彦, 塚田啓二

    応用物理学会秋季学術講演会講演予稿集(CD-ROM)   76th   2015年

     詳細を見る

  • HTS-SQUIDを用いたMPIシステムの赤外光による空間分解能向上の検討

    森田洪爾, SAARI Mohd Mawardi, 松永恭暁, 堺健司, 紀和利彦, 塚田啓二

    応用物理学会秋季学術講演会講演予稿集(CD-ROM)   76th   2015年

     詳細を見る

  • テラヘルツ波ケミカル顕微鏡を用いた液中イオンの同時検出

    秋宗広祐, 大川裕貴, 紀和利彦, 堺健二, 塚田啓二

    応用物理学会春季学術講演会講演予稿集(CD-ROM)   62nd   2015年

     詳細を見る

  • テラヘルツ技術の最前線-光源と応用の最新動向-テラヘルツ波ケミカル顕微鏡の開発

    紀和利彦, 堺健司, 塚田啓二

    Optronics   ( 405 )   2015年

     詳細を見る

  • テラヘルツ波ケミカル顕微鏡による生体関連物質相互作用検出

    紀和利彦, 秋宗広祐, 周益, 堺健司, 塚田啓二

    日本分析化学会年会講演要旨集   64th   2015年

     詳細を見る

  • 低周波磁場を用いた鋼板の厚み測定システムの開発

    森田洪爾, 芳賀勇太, 堺健司, 紀和利彦, 塚田啓二

    電気・情報関連学会中国支部連合大会講演論文集(CD-ROM)   66th   2015年

     詳細を見る

  • HTS-SQUIDを用いた電流分布測定による各種太陽電池の評価

    田中洸平, SAARI Mohd Mawardi, 堺健司, 紀和利彦, 塚田啓二

    電気・情報関連学会中国支部連合大会講演論文集(CD-ROM)   66th   2015年

     詳細を見る

  • 接線2成分磁場合成による電流分布の可視化と欠陥推定への利用

    八杉拓也, 志賀啓秀, SONG Nannan, 堺健司, 紀和利彦, 塚田啓二

    日本非破壊検査協会秋季講演大会講演概要集   2015   2015年

     詳細を見る

  • TMRセンサ高調波信号を用いた非破壊検査システムの開発と画像化

    八杉拓也, 志賀啓秀, 塚本有哉, 堺健司, 紀和利彦, 塚田啓二

    表面探傷シンポジウム講演論文集   18th   2015年

     詳細を見る

  • 自動走行システムを用いたコンテナクレーン鋼構造部の漏洩磁束探傷法による非破壊検査

    堺健司, 森田洪爾, 芳賀勇太, 紀和利彦, 塚田啓二, 井上勝美

    表面探傷シンポジウム講演論文集   18th   2015年

     詳細を見る

  • AMRセンサアレイを用いた漏洩磁束探傷試験による鋼板の裏面欠陥検出

    森田洪爾, 塚本有哉, 志賀啓秀, 芳賀勇太, 堺健司, 紀和利彦, 塚田啓二

    電気学会全国大会講演論文集(CD-ROM)   2015   2015年

     詳細を見る

  • 超薄膜Pt/Tiを用いたブリッジ型水素センサの開発

    井並祥太, 牛田祐貴, 武市修蔵, 菅井良祐, 堺健司, 紀和利彦, 塚田啓二

    応用物理学会春季学術講演会講演予稿集(CD-ROM)   62nd   2015年

     詳細を見る

  • 磁気センサアレイを用いた漏洩磁束法による裏面腐食欠陥検査

    芳賀勇太, 森田洪爾, 堺健司, 紀和利彦, 塚田啓二

    表面探傷シンポジウム講演論文集   18th   2015年

     詳細を見る

  • テラヘルツ波ケミカル顕微鏡によるD-(+)-マンノースの非標識検出

    小川真寛, 中村彰宏, 紀和利彦, 堺健司, 塚田啓二

    応用物理学会春季学術講演会講演予稿集(CD-ROM)   62nd   2015年

     詳細を見る

  • 高温超伝導SQUIDを用いた磁化率計開発

    紀和利彦, 堺健司, SAARI Mohd Mawardi, 塚田啓二

    電子情報通信学会大会講演論文集(CD-ROM)   2015   2015年

     詳細を見る

  • TMRセンサを用いた欠陥の渦電流探傷検査

    志賀啓秀, 八杉拓也, 塚本有哉, 堺健司, 紀和利彦, 塚田啓二

    電気学会全国大会講演論文集(CD-ROM)   2015   2015年

     詳細を見る

  • HTS-SQUIDを用いた高機能サンプル振動型磁化率計の開発

    松永恭暁, SAARI Mohd Mawardi, 日下瞬, 森田洪爾, 堺健司, 紀和利彦, 塚田啓二

    応用物理学会春季学術講演会講演予稿集(CD-ROM)   62nd   2015年

     詳細を見る

  • SQUIDグラジオメータを用いた2ch.磁気計測システムの開発

    田中洸平, 糟谷尚平, 石原優一, SAARI Mohd Mawardi, 堺健司, 紀和利彦, 塚田啓二

    電気学会全国大会講演論文集(CD-ROM)   2015   2015年

     詳細を見る

  • テラヘルツ波の新時代 テラヘルツ波ケミカル顕微鏡=新しい非標識バイオイセンシングツールの開発=

    紀和利彦

    光アライアンス   26 ( 1 )   2015年

     詳細を見る

  • 超薄膜水素センサの安定性改善

    井並祥太, 菅井良祐, 堺健司, 紀和利彦, 塚田啓二

    応用物理・物理系学会中国四国支部合同学術講演会講演予稿集   2015   2015年

     詳細を見る

  • Stabilization method for signal drifts in terahertz chemical microscopy. 国際誌

    Toshihiko Kiwa, Kenji Sakai, Keiji Tsukada

    Optics express   22 ( 2 )   1330 - 5   2014年1月

     詳細を見る

    記述言語:英語   出版者・発行元:OPTICAL SOC AMER  

    A stabilization method for signal drifts in terahertz chemical microscopy (TCM) due to unexpected chemical potential changes in sample solutions was proposed and developed. The sensing plate was separated into two areas: a detection area and a control area. The detection area radiated a THz pulse whose amplitude was related to both the chemical reactions in the sample solutions and unexpected potential changes. The THz pulse from the control area was related only to unexpected potential changes. In the proposed system, the THz pulse from each area was interfered and detected. By adjusting the timing of the positive peak of the THz pulse from the detection area and the negative peak of the THz pulse from the control area, we detected the difference in both peaks as the interference signal. Thus, the signal deviation of 390 when the environmental condition changes in the temperature range of 38 °C and the pH range of 8.33 was stabilized to be the signal deviation of 31. As the result, the TCM with stabilization method could detect the signal shift of 121 when the 275-nmol/L immunoglobulin G was immobilized on the sensing plate.

    DOI: 10.1364/OE.22.001330

    Web of Science

    Scopus

    PubMed

    researchmap

  • HTS-SQUIDを用いた電解質中イオン輸送の可視化

    紀和利彦, 糟谷尚平, 宮崎真吾, 堺健司, 塚田啓二

    応用物理学会春季学術講演会講演予稿集(CD-ROM)   61st   2014年

     詳細を見る

  • 渦電流探傷検査法を用いたスポット溶接の検査法の開発

    志賀啓秀, 塚本有哉, SONG Nannan, 堺健司, 紀和利彦, 塚田啓二

    電磁力関連のダイナミクスシンポジウム講演論文集   26th   2014年

     詳細を見る

  • HTS-SQUIDを用いた小型AC/DC磁化率計の研究開発

    森田洪爾, MOHD Mawardi, 高木竜輝, 石原優一, 日下瞬, 塚本有哉, 堺健司, 紀和利彦, 塚田啓二

    電気学会全国大会講演論文集(CD-ROM)   2014   2014年

     詳細を見る

  • HTS-SQUIDグラジオメータを用いた太陽電池評価システムの開発

    田中洸平, 宮崎真伍, 糟谷尚平, SAARI Mohd Mawardi, 堺健司, 紀和利彦, 塚田啓二

    電気学会全国大会講演論文集(CD-ROM)   2014   2014年

     詳細を見る

  • 高温超伝導SQUIDを用いた磁気計測システムの高精度化と水分量計測への応用

    堺健司, 渡部裕太, 岡本直大, SAARI Mohd Mawardi, 紀和利彦, 塚田啓二

    MAGDAコンファレンス講演論文集   23rd   2014年

     詳細を見る

  • スポット溶接内部構造解析用3Dマップの開発

    SONG Nannan, 塚本有哉, 志賀啓秀, 原田大地, 堺健司, 紀和利彦, CHENG Weiying, 塚田啓二

    日本非破壊検査協会講演大会講演概要集   2014   2014年

     詳細を見る

  • 磁場分布自動計測システムを用いた鋼材の疲労度評価の検討

    堺健司, 秋山貴俊, 紀和利彦, 井上勝美, 塚田啓二

    日本非破壊検査協会講演大会講演概要集   2014   2014年

     詳細を見る

  • 漏洩磁束探傷法を用いた鋼構造部内部腐食の検出

    堺健司, 秋山貴俊, 紀和利彦, 塚田啓二

    日本非破壊検査協会講演大会講演概要集   2014   2014年

     詳細を見る

  • HTS-SQUIDを用いた電解質中イオン輸送の可視化(II)

    紀和利彦, 田中洸平, 糟谷尚平, 堺健司, 塚田啓二

    応用物理学会秋季学術講演会講演予稿集(CD-ROM)   75th   2014年

     詳細を見る

  • 白金超薄膜を用いたブリッジ型水素センサ

    牛田祐貴, 武市修蔵, 菅井良祐, 井波祥太, 堺健司, 紀和利彦, 塚田啓二

    電気・情報関連学会中国支部連合大会講演論文集(CD-ROM)   65th   2014年

     詳細を見る

  • テラヘルツ波ケミカル顕微鏡による燃料電池の触媒反応解析

    古礒和樹, 日下鉄也, 紀和利彦, 堺健司, 塚田啓二

    応用物理学会秋季学術講演会講演予稿集(CD-ROM)   75th   2014年

     詳細を見る

  • 超伝導エレクトロニクス(その1)HTS-SQUIDを用いた試料回転式小型磁化率計の開発と応用展開

    堺健司, SAARI Mohd Mawardi, 紀和利彦, 塚田啓二

    低温工学   49 ( 7 )   2014年

     詳細を見る

  • HTS-SQUID回転型磁化率計の高感度化の研究

    渡部裕太, 岡本直大, SAARI Mohd Mawardi, 堺健司, 紀和利彦, 塚田啓二

    応用物理・物理系学会中国四国支部合同学術講演会講演予稿集   2014   2014年

     詳細を見る

  • 直冷式HTS-SQUIDを用いた太陽電池の光応答特性評価システムの開発

    田中洸平, 糟谷尚平, SAARI Mohd Mawardi, 堺健司, 紀和利彦, 塚田啓二

    応用物理・物理系学会中国四国支部合同学術講演会講演予稿集   2014   2014年

     詳細を見る

  • HTS-SQUIDを用いた高精度磁化率計の開発と水溶液中の磁気ナノ粒子への応用

    森田洪爾, SAARI Mohd Mawardi, 石原優一, 日下瞬, 塚本有哉, 堺健司, 紀和利彦, 塚田啓二

    応用物理・物理系学会中国四国支部合同学術講演会講演予稿集   2014   2014年

     詳細を見る

  • 高温超伝導SQUIDを用いた磁化率計の複合型AC/DC検出ユニットの最適化

    SAARI Mohd Mawardi, 森田洪爾, 石原優一, 日下瞬, 堺健司, 紀和利彦, 塚田啓二

    応用物理学会秋季学術講演会講演予稿集(CD-ROM)   75th   2014年

     詳細を見る

  • 高感度磁気センサの非破壊検査への応用 磁気抵抗効果センサを用いた非破壊検査

    紀和利彦, 堺健司, 塚田啓二

    非破壊検査   63 ( 11 )   2014年

     詳細を見る

  • HTS-SQUIDを用いた試料回転式磁化率計の試料形状最適化による高感度計測法の検討

    堺健司, 岡本直大, 渡部裕太, SAARI Mohd Mawardi, 紀和利彦, 塚田啓二

    電子情報通信学会大会講演論文集(CD-ROM)   2014   2014年

     詳細を見る

  • 超薄膜Pt/Tiを用いたブリッジ型水素センサの開発

    菅井良祐, 武市修蔵, 牛田祐貴, 井並祥太, 堺健司, 紀和利彦, 塚田啓二

    センサ・マイクロマシンと応用システムシンポジウム(CD-ROM)   31st   2014年

     詳細を見る

  • AC/DC高温超伝導SQUID磁化率計による水溶液中の酸化鉄ナノ粒子の磁気特性計測

    SAARI Mohd Mawardi, 塚本有哉, 石原優一, 日下瞬, 堺健司, 紀和利彦, 塚田啓二

    応用物理学会春季学術講演会講演予稿集(CD-ROM)   61st   2014年

     詳細を見る

  • 保温材下配管外面欠陥の磁気的検査装置の開発

    原拓也, 春日基志, 堺健司, 紀和利彦, 塚田啓二

    日本磁気学会学術講演概要集   38th   2014年

     詳細を見る

  • TMRセンサを用いた裏面欠陥の漏洩磁束探傷検査

    志賀啓秀, 塚本有哉, 堺健司, 紀和利彦, 西川卓男, 塚田啓二

    日本磁気学会学術講演概要集   38th   2014年

     詳細を見る

  • 三層鋼板スポット溶接の磁気を用いた非破壊検査

    原田大地, 堺健司, 紀和利彦, 塚田啓二

    非破壊検査   63 ( 9 )   2014年

     詳細を見る

  • THz-TDSによるPEフィルム含水量の非破壊検査法

    松岡泰正, 紀和利彦, 堺健司, 塚田啓二

    応用物理学会秋季学術講演会講演予稿集(CD-ROM)   75th   2014年

     詳細を見る

  • 磁場を用いた保温材下配管の外面欠陥検出と位置特定の検討

    堺健司, 春日基志, 橋本源基, 紀和利彦, 塚田啓二, 河部俊英

    表面探傷シンポジウム講演論文集   17th   2014年

     詳細を見る

  • 産業応用に向けたテラヘルツ波ケミカル顕微鏡の開発

    紀和利彦, 堺健司, 塚田啓二

    農業食料工学会誌   76 ( 3 )   2014年

     詳細を見る

  • トンネル型磁気抵抗素子を用いた裏面欠陥非破壊検査

    塚本有哉, 志賀啓秀, 堺健司, 紀和利彦, 西川卓男, 塚田啓二

    電磁力関連のダイナミクスシンポジウム講演論文集   26th   2014年

     詳細を見る

  • HTS-SQUIDを用いた試料回転式磁化率計の高感度化と磁気緩和信号の測定

    堺健司, 岡本直大, 浜崎大地, SAARI Mohd Mawardi, 紀和利彦, 塚田啓二

    電子情報通信学会技術研究報告   113 ( 401(SCE2013 35-57) )   2014年

     詳細を見る

  • HTS-SQUIDを用いた磁気応答計測システムの高感度化による水分量評価への応用

    堺健司, 日下瞬, 岡本直大, 浜崎大地, SAARI Mohd Mawardi, 紀和利彦, 塚田啓二

    電子情報通信学会大会講演論文集(CD-ROM)   2014   2014年

     詳細を見る

  • Optimization of the Detection Technique for a Vibrating-Sample Magnetometer Using High-T-c SQUID

    Mohd Mawardi Saari, Kenji Sakai, Toshihiko Kiwa, Keiji Tsukada

    IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY   23 ( 3 )   1600204   2013年6月

     詳細を見る

    記述言語:英語   出版者・発行元:IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC  

    We have developed a compact vibrating-sample magnetometer that uses a high-temperature superconductor superconducting quantum interference device (high-T-c SQUID) and a normal conductive pickup coil. To further increase the sensitivity of the developed system, we consider a technique to detect harmonic components induced at the pickup coil. We optimized the geometry of the pickup coil and sample to maximize the harmonic signals and compared the harmonic signals induced from different shapes of coils using simulation and experimental methods. The simulation and the experimental results agreed well, indicating that the optimized geometry of the pickup coil improves the induced harmonic components. Improvement in sensitivity with reduced mechanical noise can be attained using this detection technique.

    DOI: 10.1109/TASC.2012.2227919

    Web of Science

    researchmap

  • テラヘルツケミカル顕微鏡と応用開拓

    紀和 利彦

    O plus E   35 ( 2 )   147 - 151   2013年

     詳細を見る

    担当区分:筆頭著者, 責任著者  

    researchmap

  • Compact rotating-sample magnetometer for relaxation phenomenon measurement using HTS-SQUID

    Kenji Sakai, Mohd Mawardi Saari, Toshihiko Kiwa, Keiji Tsukada

    IEEE Transactions on Applied Superconductivity   23 ( 3 )   1601904   2013年

     詳細を見る

    記述言語:英語   出版者・発行元:IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC  

    A compact magnetometer that uses a high-temperature superconductor superconducting quantum interference device (HTS-SQUID) that can measure relaxation phenomena was developed, and its characteristics were evaluated. For measuring magnetic relaxation, a pick-up coil was designed to be fixed at any position in the circle described by a rotating-sample. The pick-up coil was directly connected to an input coil, which is inductively connected to the HTS-SQUID, and the secondary induced magnetic field from the sample was detected with time delay after magnetization. Using the developed system, magnetic signals with time delay from pure water were detected, and the magnetic signal intensity decreased with increasing time delay. This magnetic signal with time delay was not caused by the sample case and the magnetization due to the leaked magnetic field distribution of the permanent magnet used for sample magnetization. Thus, the developed system could detect magnetic signals during the magnetic relaxation process. © 2012 IEEE.

    DOI: 10.1109/TASC.2012.2234324

    Web of Science

    Scopus

    researchmap

  • Magnetic detection of currents in an electrolytic cell using high-T <inf>C</inf> SQUID

    Toshihiko Kiwa, Yohei Fukudome, Shingo Miyazaki, Mohd Mawardi Saari, Kenji Sakai, Akira Tsukamoto, Seiji Adachi, Keiichi Tanabe, Akihiko Kandori, Keiji Tsukada

    IEEE Transactions on Applied Superconductivity   23 ( 3 )   1600804   2013年

     詳細を見る

    記述言語:英語   出版者・発行元:IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC  

    A magneto-electrical cyclic voltammetry has been proposed and developed. This measurement method utilized three electrodes: a counter, a working, and a reference electrode, as the conventional voltammetry uses and the magnetic field by the currents were detected. Thus, the current distribution in the electrolyte cells during the voltammetry measurements could be visualized. In this work, the current in the cell was observed during the pulse voltammetry using the high-TC SQUID with the normal pick-up coils. The pick-up coil was aligned parallel to the surface of the cell. Obtained magnetic signals could be related to the current measured by the conventional method. © 2002-2011 IEEE.

    DOI: 10.1109/TASC.2012.2228736

    Web of Science

    Scopus

    researchmap

  • Magnetic evaluation of a solar panel using HTS-SQUID

    Toshihiko Kiwa, Yohei Fukudome, Shingo Miyazaki, Mohd Mawardi Saari, Kenji Sakai, Keiji Tsukada

    Physica C: Superconductivity and its Applications   494 ( 15 )   195 - 198   2013年

     詳細を見る

    記述言語:英語   出版者・発行元:ELSEVIER SCIENCE BV  

    The magnetic evaluation system of a solar panel using HTS-SQUID has been proposed and developed. A normal pick-up coil was applied to detect the tangential magnetic field to the panel surface. Since the detected field could be related to the currents of the solar panels, the electric properties of the solar panels could be evaluated. In this work, the evaluation of the electric properties of the commercial solar panels as well as the electric circuits made by the discrete devices on the circuit board was visualized. © 2013 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.physc.2013.04.080

    Web of Science

    Scopus

    researchmap

  • 高温超伝導SQUIDを用いたDC/AC複合小型磁化率計の開発

    高木竜輝, MOHD Mawardi Saari, 石原優一, 堺健司, 紀和利彦, 塚田啓二

    低温工学・超電導学会講演概要集   87th   2013年

     詳細を見る

  • HTS-SQUIDを用いた磁気緩和測定システムの高精度化

    堺健司, 岡本直大, 浜崎大地, SAARI Mohd Mawardi, 紀和利彦, 塚田啓二

    電子情報通信学会大会講演論文集(CD-ROM)   2013   2013年

     詳細を見る

  • HTS-SQUIDを用いた試料回転型磁化率計の最適化と水分量計測への応用

    堺健司, 日下瞬, 岡本直大, 浜崎大地, SAARI Mohd Mawardi, 紀和利彦, 塚田啓二

    電子情報通信学会技術研究報告   113 ( 232(SCE2013 19-34) )   2013年

     詳細を見る

  • HTS-SQUIDグラジオメータを用いた太陽電池直流電流計測システムの開発

    宮崎真伍, 糟谷尚平, SAARI Mohd Mawardi, 堺健司, 紀和利彦, 塚本晃, 安達誠司, 田辺圭一, 塚田啓二

    応用物理学会秋季学術講演会講演予稿集(CD-ROM)   74th   2013年

     詳細を見る

  • 高温超伝導SQUIDを用いたDC・AC複合小型磁化率計の開発

    石原優一, SAARI Mohd Mawardi, 高木竜輝, 堺健司, 紀和利彦, 塚田啓二

    日本磁気学会学術講演概要集   37th   2013年

     詳細を見る

  • 高温超伝導SQUIDを用いた小型磁化率計による水分量測定

    日下瞬, SAARI Mohd Mawardi, 堺健司, 紀和利彦, 塚田啓二

    日本磁気学会学術講演概要集   37th   2013年

     詳細を見る

  • HTS-SQUIDを用いた交流磁化率計の開発とシステムの最適化

    堺健司, 浜崎大地, SAARI Mohd Mawardi, 紀和利彦, 塚田啓二

    電子情報通信学会技術研究報告   113 ( 149(SCE2013 10-18) )   2013年

     詳細を見る

  • THz波ケミカル顕微鏡による燃料電池の触媒反応解析システムの開発

    日下鉄也, 萩原隆文, 堺健司, 紀和利彦, 塚田啓二

    応用物理学会秋季学術講演会講演予稿集(CD-ROM)   74th   2013年

     詳細を見る

  • HTS-SQUID磁気計測による太陽電池電気特性評価

    宮崎真伍, 福留陽平, SAARI Mohd Mawardi, 堺健司, 紀和利彦, 塚田啓二

    電子情報通信学会大会講演論文集   2013   2013年

     詳細を見る

  • HTS-SQUIDを用いたサンプル回転方式小型磁気計測計による磁気緩和測定

    浜崎大地, SAARI Mohd Mawardi, 堺健司, 紀和利彦, 塚田啓二

    電気学会全国大会講演論文集   2013 ( 2 )   2013年

     詳細を見る

  • HTS-SQUIDを用いた電気磁気化学計測システムの開発(II)

    紀和利彦, 福留陽平, 宮崎真伍, 高木竜輝, 堺健司, 塚田啓二

    応用物理学会春季学術講演会講演予稿集(CD-ROM)   60th   2013年

     詳細を見る

  • 白金メタマテリアル構造の水素応答評価

    園拓也, 篠宮光博, 堺健司, 紀和利彦, 塚田啓二

    応用物理学会春季学術講演会講演予稿集(CD-ROM)   60th   2013年

     詳細を見る

  • HTS-SQUIDを用いたサンプル回転式小型磁化率計の高感度計測手法の検討

    堺健司, 浜崎大地, SAARI Mohd Mawardi, 紀和利彦, 塚田啓二

    電子情報通信学会技術研究報告   112 ( 408(SCE2012 25-38) )   2013年

     詳細を見る

  • 漏洩磁束探傷法を用いた鋼板の疲労度検出システムの開発

    堺健司, 紀和利彦, 塚田啓二, 井上勝美

    表面探傷シンポジウム講演論文集   16th   2013年

     詳細を見る

  • HTS-SQUIDを用いた試料回転式小型磁化率計のシステム改善による高感度化

    堺健司, 浜崎大地, SAARI Mohd Mawardi, 紀和利彦, 塚田啓二

    電子情報通信学会大会講演論文集   2013   2013年

     詳細を見る

  • HTS-SQUIDによる試料回転式小型磁化率計を用いた水分量計測

    堺健司, 浜崎大地, SAARI Mohd Mawardi, 紀和利彦, 塚田啓二

    応用物理学会春季学術講演会講演予稿集(CD-ROM)   60th   2013年

     詳細を見る

  • 高感度計測法を用いた高温超伝導SQUID磁化率計

    SAARI Mohd Mawardi, 高木竜輝, 堺健司, 紀和利彦, 塚田啓二

    応用物理学会春季学術講演会講演予稿集(CD-ROM)   60th   2013年

     詳細を見る

  • HTS-SQUIDを用いたサンプル回転型小型磁化率計の開発

    岡本直大, 浜崎大地, SAARI M. M., 堺健司, 紀和利彦, 塚田啓二

    日本磁気学会学術講演概要集   37th   2013年

     詳細を見る

  • 三層鋼板スポット溶接の磁気を用いた非破壊検査

    原田大地, 堺健司, 紀和利彦, 塚田啓二

    日本非破壊検査協会講演大会講演概要集   2013   2013年

     詳細を見る

  • スポット溶接内部構造解析用磁気位相マップの開発

    SONG Nannan, 塚本有哉, 志賀啓秀, 原田大地, 堺健司, 紀和利彦, CHENG Weiying, 塚田啓二

    日本非破壊検査協会講演大会講演概要集   2013   2013年

     詳細を見る

  • HTS-SQUID磁気特性評価装置におけるAC磁場検出方法の最適化

    石原優一, SAARI Mohd Mawardi, 高木竜輝, 堺健司, 紀和利彦, 塚田啓二

    応用物理・物理系学会中国四国支部合同学術講演会講演予稿集   2013   2013年

     詳細を見る

  • テラヘルツ波ケミカル顕微鏡によるイオン計測システムの開発

    大川裕貴, 萩原隆文, 堺健司, 紀和利彦, 塚田啓二

    応用物理学会秋季学術講演会講演予稿集(CD-ROM)   74th   2013年

     詳細を見る

  • テラヘルツ波光源と応用 テラヘルツ波ケミカル顕微鏡と応用開拓

    紀和利彦

    O plus E   ( 399 )   2013年

     詳細を見る

  • テラヘルツ波による生体関連物質化学反応センシング

    紀和利彦, 萩原隆文, 大村健, 高橋慎治, 堺健司, 塚田啓二

    応用物理学会秋季学術講演会講演予稿集(CD-ROM)   74th   2013年

     詳細を見る

  • HTS-SQUID磁気特性評価装置における高調波検波方式の研究

    塚本有哉, SAARI Mohd Mawardi, 高木竜輝, 堺健司, 紀和利彦, 塚田啓二

    応用物理・物理系学会中国四国支部合同学術講演会講演予稿集   2013   2013年

     詳細を見る

  • 高速スキャン型テラヘルツ分光ユニットの雑音特性

    難波勇馬, 園拓也, 堺健司, 紀和利彦, 塚田啓二

    応用物理・物理系学会中国四国支部合同学術講演会講演予稿集   2013   2013年

     詳細を見る

  • テラヘルツ電磁波を用いたSiGe薄膜評価システムの開発

    中村彰宏, 大村健, 堺健司, 紀和利彦, 塚田啓二

    応用物理・物理系学会中国四国支部合同学術講演会講演予稿集   2013   2013年

     詳細を見る

  • 回転型HTS-SQUID磁化率計の高感度検出法の研究

    岡本直大, 浜崎大地, SAARI Mohd Mawardi, 堺健司, 紀和利彦, 塚田啓二

    応用物理・物理系学会中国四国支部合同学術講演会講演予稿集   2013   2013年

     詳細を見る

  • HTS-SQUIDを用いたサンプル回転方式小型磁化率計の高感度化

    浜崎大地, 岡本直大, SAARI Mohd Mawardi, 堺健司, 紀和利彦, 塚田啓二

    応用物理学会秋季学術講演会講演予稿集(CD-ROM)   74th   2013年

     詳細を見る

  • 保温材下配管外面欠陥の磁気的検査装置の開発

    春日基志, 橋本源基, 堺健司, 紀和利彦, 塚田啓二

    電気・情報関連学会中国支部連合大会講演論文集(CD-ROM)   64th   2013年

     詳細を見る

  • 白金薄膜抵抗の構造変化による水素応答評価とブリッジ型水素センサの開発

    牛田祐貴, 奥井貴博, 武市修蔵, 堺健司, 紀和利彦, 塚田啓二

    電気・情報関連学会中国支部連合大会講演論文集(CD-ROM)   64th   2013年

     詳細を見る

  • HTS-SQUIDを用いた太陽電池の光応答特性分布解析

    糟谷尚平, 宮崎真伍, SAARI Mohd Mawardi, 堺健司, 紀和利彦, 塚田啓二

    応用物理・物理系学会中国四国支部合同学術講演会講演予稿集   2013   2013年

     詳細を見る

  • 高温超伝導SQUIDを用いた磁気特性評価装置によるモルタル水分量測定

    日下瞬, SAARI Mohd Mawardi, 堺健司, 紀和利彦, 塚田啓二

    応用物理・物理系学会中国四国支部合同学術講演会講演予稿集   2013   2013年

     詳細を見る

  • 白金薄膜の表面構造による水素応答評価

    武市修蔵, 奥井貴博, 牛田祐貴, 堺健司, 紀和利彦, 塚田啓二

    センサ・マイクロマシンと応用システムシンポジウム(CD-ROM)   30th   2013年

     詳細を見る

  • HTS-SQUIDを用いたAC/DC複合小型磁化率計の開発

    高木竜輝, 石原優一, SAARI Mohd Mawardi, 堺健司, 紀和利彦, 塚田啓二

    応用物理学会秋季学術講演会講演予稿集(CD-ROM)   74th   2013年

     詳細を見る

  • 白金薄膜抵抗を用いたブリッジ回路型水素センサの開発

    牛田祐貴, 奥井貴博, 武市修蔵, 堺健司, 紀和利彦, 塚田啓二

    センサ・マイクロマシンと応用システムシンポジウム(CD-ROM)   30th   2013年

     詳細を見る

  • 低周波磁場を用いた金属疲労画像化装置

    秋山貴俊, 堺健司, 紀和利彦, 塚田啓二

    電気・情報関連学会中国支部連合大会講演論文集(CD-ROM)   64th   2013年

     詳細を見る

  • 保温材下配管外面欠陥の磁気的検査装置の開発-その3

    橋本源基, 堺健司, 紀和利彦, 塚田啓二

    日本非破壊検査協会講演大会講演概要集   2013   2013年

     詳細を見る

  • テラヘルツ波を用いた生体関連イオン計測手法の開発

    大川裕貴, 萩原隆文, 堺健司, 紀和利彦, 塚田啓二

    応用物理・物理系学会中国四国支部合同学術講演会講演予稿集   2013   2013年

     詳細を見る

  • テラヘルツ波ケミカル顕微鏡を用いた寒天ゲル膜の評価

    中村彰宏, 大村健, 堺健司, 紀和利彦, 塚田啓二

    日本分光学会テラヘルツ分光部会シンポジウム講演要旨集   2013   2013年

     詳細を見る

  • THz波ケミカル顕微鏡による発電中の燃料電池触媒反応解析

    日下鉄也, 萩原隆文, 堺健司, 紀和利彦, 塚田啓二

    応用物理・物理系学会中国四国支部合同学術講演会講演予稿集   2013   2013年

     詳細を見る

  • テラヘルツ波バイオ検査装置の開発と現状

    紀和利彦

    日本分光学会テラヘルツ分光部会シンポジウム講演要旨集   2013   2013年

     詳細を見る

  • 白金ナノ薄膜の水素応答評価

    武市修蔵, 奥井貴博, 牛田祐貴, 堺健司, 紀和利彦, 塚田啓二

    電気・情報関連学会中国支部連合大会講演論文集(CD-ROM)   64th   2013年

     詳細を見る

  • 高温超伝導SQUIDを用いた小型サンプル振動方式磁化率計とサンプル形状の依存性

    モハマド マワルディ サーリ, 高木 竜輝, 堺 健司, 紀和 利彦, 塚本 晃, 安達 成司, 田辺 圭一, 神鳥 明彦, 塚田 啓二

    電子情報通信学会技術研究報告. SCE, 超伝導エレクトロニクス   112 ( 138 )   31 - 36   2012年7月

     詳細を見る

    記述言語:英語   出版者・発行元:一般社団法人電子情報通信学会  

    本研究では,高温超伝導SQUIDを用いた小型磁化率計の開発を行った.開発した計測システムの基礎特性を評価し実験とシミュレーションの解析方法を用いてサンプル形状とピックアップコイルの配置等の最適値を調べた.システムの最適化によって本計測システムは1×10^<-7>emuの感度を得られた.その応用として水の弱い反磁性を測定することに成功した.

    CiNii Article

    CiNii Books

    researchmap

  • Work function shifts of catalytic metals under hydrogen gas visualized by terahertz chemical microscopy. 国際誌

    Toshihiko Kiwa, Takafumi Hagiwara, Mitsuhiro Shinomiya, Kenji Sakai, Keiji Tsukada

    Optics express   20 ( 11 )   11637 - 42   2012年5月

     詳細を見る

    記述言語:英語   出版者・発行元:OPTICAL SOC AMER  

    Terahertz chemical microscopy (TCM) was applied to visualize the distribution of the work function shift of catalytic metals under hydrogen gas. TCM measures the chemical potential on the surface of a SiO(2)/Si/sapphire sensing plate without any contact with the plate. By controlling the bias voltage between an electrode on the SiO(2)/ surface and the Si layer, the relationship between the voltage and the THz amplitude from the sensing plate can be obtained. As a demonstration, two types of structures were fabricated on the sensing plate, and the work function shifts due to catalytic reactions were visualized.

    DOI: 10.1364/OE.20.011637

    Web of Science

    Scopus

    PubMed

    researchmap

  • Development of a compact moving-sample magnetometer using high-Tc superconducting quantum interference device

    Mohd Mawardi Saari, Kenji Sakai, Toshihiko Kiwa, Akira Tsukamoto, Seiji Adachi, Keiichi Tanabe, Akihiko Kandori, Keiji Tsukada

    Japanese Journal of Applied Physics   51 ( 4 PART 1 )   046601   2012年4月

     詳細を見る

    記述言語:英語   出版者・発行元:IOP PUBLISHING LTD  

    We developed a compact moving-sample magnetometer that uses a high-temperature superconductor-superconducting quantum interference device (high-T c SQUID) to directly measure the flux coupled to a normal detection coil from a sample's magnetic moment in the presence of an external DC magnetic field. The moving-sample method is employed by inserting the sample between the poles of a DC electromagnet and vibrating the sample along the axis perpendicular to the external field axis using an actuator at a frequency of 2.693 Hz. First, the magnetic field of the sample is transferred by a first-order differential normal Cu coil to a SQUID for detection. Then, the SQUID output is fed to a lock-in amplifier for detection. The critical feature of the system design is the use of high-T c SQUID, which enables the realization of a compact system. The basic characteristics of the developed system are presented, and the current system exhibited a detection limit of 1 x 10 -7 emu. © 2012 The Japan Society of Applied Physics.

    DOI: 10.1143/JJAP.51.046601

    Web of Science

    Scopus

    researchmap

  • Electric Characteristics of a Loop in Which Two Junctions between a Catalytic Metal and a Noncatalytic Metal Are under Different Hydrogen Gas Concentrations

    Keiji Tsukada, Kenji Sakai, Toshihiko Kiwa

    APPLIED PHYSICS EXPRESS   5 ( 3 )   034102   2012年3月

     詳細を見る

    記述言語:英語   出版者・発行元:JAPAN SOC APPLIED PHYSICS  

    To investigate the localized electrochemical properties of an electrode composed of platinum (Pt), a thin-film loop containing two junctions between the catalytic metal Pt and the noncatalytic metal titanium was fabricated. When the loop was open and only one junction was exposed to 10% hydrogen in nitrogen gas, an output voltage change of about 30 nV was generated between these two junctions. The electron density change due to the equilibrium reaction of hydrogen dissociation along the part exposed to hydrogen induced a balance between the diffusion and drift caused by the electric field at both ends of the Pt film. (c) 2012 The Japan Society of Applied Physics

    DOI: 10.1143/APEX.5.034102

    Web of Science

    researchmap

  • Changes in work function and electrical resistance of Pt thin films in the presence of hydrogen gas

    Keiji Tsukada, Hirotsugu Inoue, Fumiya Katayama, Kenji Sakai, Toshihiko Kiwa

    Japanese Journal of Applied Physics   51 ( 1 )   015701   2012年1月

     詳細を見る

    記述言語:英語   出版者・発行元:JAPAN SOC APPLIED PHYSICS  

    The changes in the electrical properties, such as work function and resistance, of Pt thin films in the presence of hydrogen gas were studied. They were simultaneously measured with a flow-through cell at different concentrations of hydrogen gas in atmosphere containing gaseous nitrogen and that containing air. The resistance was measured by a four-terminal sensing method and the relative work function changes were measured using a field effect transistor. In both atmospheres, the resistance decreased as the concentration of hydrogen gas increased. This result was repeatable only in air because of the differences in the dynamic mechanism of increased density of electrical carriers inside the Pt film as a result of diffused H atoms. In the nitrogen atmosphere, the diffused H atoms were not easily released because of the surface barrier. On the other hand, oxygen gas reacted with H atoms at the surface and this reaction accelerated atom release into air. The work function showed repeatable responses in both atmospheres, but the response characteristics were different. The equilibrium reaction between the adsorption and desorption of hydrogen occurred at the surface in the nitrogen atmosphere, whereas the equilibrium reaction of hydrogen and oxygen to form water molecules occurred in air. The changes in work function and resistance in the presence of hydrogen were due to changes in dissociated hydrogen intensity in the bulk, as well as to the surface reactions. © 2012 The Japan Society of Applied Physics.

    DOI: 10.1143/JJAP.51.015701

    Web of Science

    Scopus

    researchmap

  • 高温超伝導SQUIDによる太陽電池検査システムの開発

    紀和利彦, 福留陽平, 堺健司, 塚本晃, 安達成司, 田辺圭一, 神鳥昭彦, 塚田啓二

    電子情報通信学会技術研究報告   111 ( 418(SCE2011 19-26) )   11 - 16   2012年

     詳細を見る

  • テラヘルツ波ケミカル顕微鏡を用いたバイオ計測

    紀和利彦

    応用物理   81 ( 4 )   298 - 303   2012年

     詳細を見る

    担当区分:筆頭著者, 責任著者  

    J-GLOBAL

    researchmap

  • テラヘルツ波ケミカル顕微鏡による抗原非標識定量計測

    高橋慎治, 天満陽, 紀和利彦, 堺健司, 塚田啓二

    応用物理学会中国四国支部・日本物理学会中国支部・四国支部・日本物理教育学会中国四国支部支部学術講演会講演予稿集   2012   2012年

     詳細を見る

  • 高温超伝導SQUIDを用いた交流磁気特性計測システムの開発

    山口嘉竜, 前田敏志, 浜崎大地, 堺健司, 紀和利彦, 塚本晃, 安達成司, 田辺圭一, 神鳥明彦, 塚田啓二

    応用物理学関係連合講演会講演予稿集(CD-ROM)   59th   2012年

     詳細を見る

  • 薄膜抵抗型水素センサの開発

    奥井貴博, 片山文哉, 堺健司, 紀和利彦, 塚田啓二

    電気学会全国大会講演論文集   2012 ( 3 )   2012年

     詳細を見る

  • 参照電極が不要なイオンセンサの応答機構解析

    山本貴文, 小森達也, 小田和代, 堺健司, 紀和利彦, 塚田啓二

    電気学会全国大会講演論文集   2012 ( 3 )   2012年

     詳細を見る

  • 電気化学インピーダンス法を用いた新型構造ナトリウムイオンセンサの応答解析

    小森達也, 山本貴文, 堺健司, 紀和利彦, 塚田啓二

    電気学会ケミカルセンサ研究会資料   CHS-12 ( 1-16 )   2012年

     詳細を見る

  • 異なる白金薄膜構造をもつ抵抗変化式水素センサの応答解析

    奥井貴博, 堺健司, 紀和利彦, 塚田啓二

    センサ・マイクロマシンと応用システムシンポジウム(CD-ROM)   29th   2012年

     詳細を見る

  • 保温材下配管外面欠陥の磁気的検査装置の開発-その2

    橋本源基, 堺健司, 紀和利彦, 塚田啓二

    日本非破壊検査協会講演大会講演概要集   2012   2012年

     詳細を見る

  • HTS-SQUIDを用いた磁気緩和測定用小型磁化率計の開発

    堺健司, SAARI Mohd Mawardi, 浜崎大地, 紀和利彦, 円福敬二, 塚田啓二

    応用物理学会学術講演会講演予稿集(CD-ROM)   73rd   2012年

     詳細を見る

  • 高温超伝導SQUIDを用いた直流磁化率計の高感度計測法

    SAARI Mohd Mawardi, 高木竜輝, 堺健司, 紀和利彦, 塚田啓二

    応用物理学会学術講演会講演予稿集(CD-ROM)   73rd   2012年

     詳細を見る

  • HTS-SQUIDを用いた電気磁気化学計測システムの開発

    紀和利彦, 宮崎真伍, 高木竜輝, 堺健司, 塚田啓二

    応用物理学会学術講演会講演予稿集(CD-ROM)   73rd   2012年

     詳細を見る

  • 完全個体型イオンセンサの応答解析とマルチイオンセンサの集積化および性能評価

    山本貴文, 小森達也, 小田和代, 堺健司, 紀和利彦, 塚田啓二

    センサ・マイクロマシンと応用システムシンポジウム(CD-ROM)   29th   2012年

     詳細を見る

  • レーザー励起THz顕微鏡によるSiGeウェハの非破壊検査

    大村健, 紀和利彦, 山下善文, 堺健司, 斗内政吉, 塚田啓二

    応用物理学関係連合講演会講演予稿集(CD-ROM)   59th   2012年

     詳細を見る

  • テラヘルツ波ケミカル顕微鏡によるタンパク質結合検出

    紀和利彦

    分光研究   61 ( 1 )   2012年

     詳細を見る

  • HTS-SQUIDを用いた太陽電池の電気特性分布計測システムの自動化

    福留陽平, SAARI Mohd Mawardi, 堺健司, 紀和利彦, 塚本晃, 安達誠司, 田辺圭一, 神鳥明彦, 塚田啓二

    応用物理学関係連合講演会講演予稿集(CD-ROM)   59th   2012年

     詳細を見る

  • 気密THz-TDSユニットの開発

    能勢秀俊, 篠宮光博, 門脇信傑, 児島孝則, 小林正樹, 奥野雅史, 紀和利彦

    応用物理学関係連合講演会講演予稿集(CD-ROM)   59th   2012年

     詳細を見る

  • 小型ピックアップコイル結合型HTS-SQUIDを用いた太陽電池特性評価システムの開発

    紀和利彦, 福留陽平, 宮崎真伍, 高木竜輝, 堺健司, 塚田啓二

    低温工学・超電導学会講演概要集   86th   2012年

     詳細を見る

  • 保温材下配管外面欠陥の磁気的検査装置の開発

    橋本源基, 堺健司, 紀和利彦, 塚田啓二

    日本非破壊検査協会講演大会講演概要集   2012   2012年

     詳細を見る

  • 磁束透過法によるスポット溶接欠陥検査

    原田大地, 塚田啓二, 紀和利彦, 堺健司

    日本非破壊検査協会講演大会講演概要集   2012   2012年

     詳細を見る

  • 高温超伝導SQUIDを用いた振動型小型磁化率計の開発

    高木竜輝, SAARI Mohd Mawardi, 堺健司, 紀和利彦, 塚田啓二

    応用物理学会中国四国支部・日本物理学会中国支部・四国支部・日本物理教育学会中国四国支部支部学術講演会講演予稿集   2012   2012年

     詳細を見る

  • HTS-SQUIDを用いたサンプル回転型直流磁化率計の開発

    浜崎大地, SAARI Mohd Mawardi, 堺健司, 紀和利彦, 塚田啓二

    応用物理学会中国四国支部・日本物理学会中国支部・四国支部・日本物理教育学会中国四国支部支部学術講演会講演予稿集   2012   2012年

     詳細を見る

  • ECTを用いたスポット溶接欠陥の内部構造解析

    原田大地, 堺健司, 紀和利彦, 塚田啓二

    日本非破壊検査協会講演大会講演概要集   2012   2012年

     詳細を見る

  • テラヘルツ波ケミカル顕微鏡によるイオン反応の可視化

    萩原隆文, 篠宮光博, 紀和利彦, 堺健司, 塚田啓二

    電気・情報関連学会中国支部連合大会講演論文集(CD-ROM)   63rd   2012年

     詳細を見る

  • HTS-SQUID磁気計測による太陽電池電気特性評価

    宮崎真伍, 福留陽平, SAARI Mohd Mawardi, 堺健司, 紀和利彦, 塚田啓二

    応用物理学会中国四国支部・日本物理学会中国支部・四国支部・日本物理教育学会中国四国支部支部学術講演会講演予稿集   2012   2012年

     詳細を見る

  • テラヘルツ波ケミカル顕微鏡を用いた触媒反応解析システムの開発

    萩原隆文, 篠宮光博, 紀和利彦, 堺健司, 塚田啓二

    電気学会ケミカルセンサ研究会資料   CHS-12 ( 1-16 )   2012年

     詳細を見る

  • テラヘルツ波ケミカル顕微鏡による化学反応分布検出システムの開発

    紀和利彦, 高橋慎司, 堺健司, 塚田啓二

    電気学会ケミカルセンサ研究会資料   CHS-12 ( 1-16 )   2012年

     詳細を見る

  • Differential conductivity mapping of solar panels using a high-T <inf>C</inf> superconductor SQUID

    T. Kiwa, S. Maeda, K. Miyake, N. Kataoka, A. Tsukamoto, S. Adachi, K. Tanabe, A. Kandori, K. Tsukada

    Physica C: Superconductivity and its Applications   471 ( 21-22 )   1238 - 1241   2011年11月

     詳細を見る

    記述言語:英語   出版者・発行元:ELSEVIER SCIENCE BV  

    To visualise the distribution of the electric property of solar cells, we developed a differential conductivity mapping system using high-TC (HTS-) superconductor SQUID with a normal conducting pick-up coil. The bias ac voltage with an offset voltage was applied to a solar panel made from amorphous silicon, and the normal component of the generated magnetic field was lock-in-detected. Thus the measured signal was converted to dB/dV properties, which are inverse-proportional to the differential resistivity, as the function of the offset voltage. By scanning the pick-up coil across the panel surface, we obtained the distribution of dB/dV properties across the solar panel was obtained by scanning the pick-up coil across the panel surface. The distribution of dB/dV on the panel differed between when the light source was on and when it was off. This result suggests that the proposed system is a potential tool for diagnosing the electric properties of solar cells. © 2011 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.physc.2011.05.168

    Web of Science

    Scopus

    researchmap

  • A magnetic flux leakage method using a magnetoresistive sensor for nondestructive evaluation of spot welds

    Keiji Tsukada, Mitsuteru Yoshioka, Toshihiko Kiwa, Yoshinobu Hirano

    NDT and E International   44 ( 1 )   101 - 105   2011年1月

     詳細を見る

    記述言語:英語   出版者・発行元:ELSEVIER SCI LTD  

    Spot welding is widely used for joining metal plates. However, a highly reliable monitoring method is needed to weld a robust structure. For this purpose, we developed a magnetic flux leakage (MFL) system using a magnetoresistive (MR) sensor for nondestructive spot-weld inspection. The magnetic flux is induced between two joined plates, and the magnetic flux leakage with a tangential component parallel to the plate surface is measured. A magnetic image at the spot-welding part is obtained by two-dimensional scanning. The connected diameter of the nugget and the maximum shear load are measured after the magnetic measurement to investigate their interrelationship. The results show that the nondestructive magnetic flux leakage test shows a good correlation with the destructive shear test. © 2010 Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.ndteint.2010.09.012

    Web of Science

    Scopus

    researchmap

  • テラヘルツを用いたバイオセンシング

    紀和利彦, 天満陽, 橋本陽平, 堺健司, 塚田啓二

    日本分光学会赤外ラマン分光部会シンポジウム   6th   2011年

     詳細を見る

  • 透過磁場検出によるスポット溶接検査法の開発

    澤井勇人, 三宅康介, 堺健司, 紀和利彦, 塚田啓二, 平野佳伸

    電気・情報関連学会中国支部連合大会講演論文集(CD-ROM)   62nd   2011年

     詳細を見る

  • 低周波磁場を用いたスポット溶接の非破壊検査

    堺健司, 三宅康介, 紀和利彦, 平野佳伸, 松元光明, 塚田啓二

    日本非破壊検査協会講演大会講演概要集   2011   2011年

     詳細を見る

  • テラヘルツ波ケミカル顕微鏡とバイオセンシング

    紀和利彦

    日本分光学会テラヘルツ分光部会シンポジウム講演要旨集   2011   2011年

     詳細を見る

  • テラヘルツ波放射制御デバイス磁気特性評価

    篠宮光博, 岡田啓太, 堺健司, 紀和利彦, 塚田啓二

    応用物理学会中国四国支部・日本物理学会中国支部・四国支部・日本物理教育学会中国四国支部支部学術講演会講演予稿集   2011   2011年

     詳細を見る

  • テラヘルツ波ケミカル顕微鏡を用いた層流イメージング

    橋本陽平, 近藤洋輔, 紀和利彦, 塚田啓二

    応用物理学関係連合講演会講演予稿集(CD-ROM)   58th   2011年

     詳細を見る

  • ダブルパルス検出法によるテラヘルツ波ケミカル顕微鏡の高感度計測

    天満陽, 近藤洋輔, 紀和利彦, 門脇信傑, 小林正樹, 塚田啓二

    応用物理学関係連合講演会講演予稿集(CD-ROM)   58th   2011年

     詳細を見る

  • 交流インピーダンス法を用いた新型イオンセンサの特性評価

    小森達也, 小田和代, 堺健司, 紀和利彦, 塚田啓二

    電気・情報関連学会中国支部連合大会講演論文集(CD-ROM)   62nd   2011年

     詳細を見る

  • High-T<sub>C</sub>SQUIDを用いた太陽電池パネル非破壊検査

    紀和利彦, 前田敏志, 三宅康介, 片岡伸夫, 堺健司, 塚本晃, 安達成司, 田辺圭一, 神鳥明彦, 塚田啓二

    応用物理学関係連合講演会講演予稿集(CD-ROM)   58th   2011年

     詳細を見る

  • HTS-SQUIDを用いた小型磁化率計の開発

    堺健司, MOHAMADO Mawarudei, 紀和利彦, 塚本晃, 安達成司, 田辺圭一, 神鳥明彦, 塚田啓二

    応用物理学関係連合講演会講演予稿集(CD-ROM)   58th   2011年

     詳細を見る

  • 参照電極不要な完全固体型マルチイオンセンサの開発

    小田和代, 小森達也, 堺健司, 紀和利彦, 塚田啓二

    電気学会ケミカルセンサ研究会資料   CHS-11 ( 1-24 )   2011年

     詳細を見る

  • 薄膜抵抗型水素センサの開発

    片山文哉, 堺健司, 紀和利彦, 塚田啓二

    電気学会マイクロマシン・センサシステム研究会資料   MSS-11 ( 1-7.9-12.14-21 )   2011年

     詳細を見る

  • 漏洩磁束探傷検査法を用いたスポット溶接欠陥検査用画像化装置の開発

    三宅康介, 吉岡光輝, 紀和利彦, 塚田啓二, 平野佳伸, 松元光明

    電気学会全国大会講演論文集   2011 ( 2 )   2011年

     詳細を見る

  • High-T<sub>c</sub>SQUIDを用いた太陽電池パネル接合容量分布計測

    紀和利彦, 福留陽平, 前田敏志, 堺健司, 塚本晃, 安達成司, 田辺圭一, 神鳥明彦, 塚田啓二

    応用物理学会学術講演会講演予稿集(CD-ROM)   72nd   2011年

     詳細を見る

  • 高温超電導SQUIDを用いた小型磁化率計の開発

    MAWARDI Mohd, 前田敏志, 堺健司, 紀和利彦, 塚本晃, 安達成司, 田辺圭一, 神鳥明彦, 塚田啓二

    応用物理学会学術講演会講演予稿集(CD-ROM)   72nd   2011年

     詳細を見る

  • ダブルパルス検出法によるテラヘルツ波ケミカル顕微鏡のノイズキャンセル

    天満陽, 紀和利彦, 門脇信傑, 小林正樹, 堺健司, 塚田啓二

    応用物理学会学術講演会講演予稿集(CD-ROM)   72nd   2011年

     詳細を見る

  • 保温断熱配管の磁気的非破壊検査方法の開発

    土井貴範, 三宅康介, 紀和利彦, 塚田啓二

    日本非破壊検査協会講演大会講演概要集   2011   2011年

     詳細を見る

  • テラヘルツ波面制御素子の放射パターン制御評価

    篠宮光博, 岡田啓太, 堺健司, 紀和利彦, 塚田啓二

    日本分光学会テラヘルツ分光部会シンポジウム講演要旨集   2011   2011年

     詳細を見る

  • High-T<sub>c</sub>SQUIDを用いた太陽電池パネル電気特性分布計測

    紀和利彦, 前田敏志, 三宅康介, 堺健司, 塚田啓二, 塚本晃, 安達成司, 田辺圭一, 神鳥明彦

    低温工学・超電導学会講演概要集   84th   2011年

     詳細を見る

  • HTS-SQUIDを用いた試料回転式小型磁化率計の開発

    堺建司, MOHD Mawardi, 紀和利彦, 塚田啓二, 塚本晃, 安達成司, 田辺圭一, 神鳥明彦

    低温工学・超電導学会講演概要集   85th   2011年

     詳細を見る

  • HTS-SQUIDを用いた交流磁化率計の開発

    前田敏志, 山口嘉竜, 堺健司, 紀和利彦, 塚田啓二, 塚本晃, 安達成司, 田辺圭一, 神鳥明彦

    低温工学・超電導学会講演概要集   84th   2011年

     詳細を見る

  • 高温超伝導SQUIDを用いた太陽電池の電気特性分布計測

    福留陽平, 前田敏志, 紀和利彦, 堺健司, 塚本晃, 安達誠司, 田辺圭一, 神鳥明彦, 塚田啓二

    応用物理学会中国四国支部・日本物理学会中国支部・四国支部・日本物理教育学会中国四国支部支部学術講演会講演予稿集   2011   2011年

     詳細を見る

  • HTS-SQUIDを用いたヘルムホルツ型交流磁化率計の開発

    山口嘉竜, 前田敏志, 堺健司, 紀和利彦, 塚本晃, 安達成司, 田辺圭一, 神鳥明彦, 塚田啓二

    応用物理学会中国四国支部・日本物理学会中国支部・四国支部・日本物理教育学会中国四国支部支部学術講演会講演予稿集   2011   2011年

     詳細を見る

  • Terahertz chemical microscope for label-free detection of protein complex

    Toshihiko Kiwa, Yousuke Kondo, Yuji Minami, Iwao Kawayama, Masayoshi Tonouchi, Keiji Tsukada

    Applied Physics Letters   96 ( 21 )   2010年5月

     詳細を見る

    記述言語:英語   出版者・発行元:AMER INST PHYSICS  

    A terahertz (THz) chemical microscope (TCM) has been proposed and developed for label-free analysis of the interactions of proteins, including immune reactions. A SiO2/Si/sapphire plate was fabricated and emitted THz pulses from the sapphire side using a femtosecond laser. The amplitude of a THz pulse depends on the chemical potential of the SiO2 surface. As an initial demonstration, a biotin-avidin complex was analyzed using TCM. Results indicate that biotin concentrations of up to 10-12 mol/l could be detected, suggesting that a high sensitivity immunoassay system can be realized using this method. The distribution of the THz peak amplitude was measured, reflecting the distribution of the biotin-avidin complex on the plate. © 2010 American Institute of Physics.

    DOI: 10.1063/1.3441408

    Web of Science

    Scopus

    researchmap

  • Dual-Gate field-effect transistor hydrogen gas sensor with thermal compensation

    Keiji Tsukada, Masatoshi Kariya, Tomiharu Yamaguchi, Toshihiko Kiwa, Hironobu Yamada, Tsuneyoshi Maehara, Tadayoshi Yamamoto, Shinsuke Kunitsugu

    Japanese Journal of Applied Physics   49 ( 2 Part 1 )   2010年2月

     詳細を見る

    記述言語:英語   出版者・発行元:IOP PUBLISHING LTD  

    We developed a dual-gate field-effect transistor (FET) hydrogen gas sensor for application to hydrogen vehicles. The dual-gate FET hydrogen sensor was integrated with a Pt-gate FET to detect hydrogen and a Ti-gate FET as the reference sensor in the same Si chip. The Ti-FET had the same structure as the Pt-FET except for the gate metal. The Pt-FET showed a good response to hydrogen gas above 10ppm in air, while the Ti-FET did not show any response to hydrogen gas. The differential output voltage between the Pt-FET and the Ti-FET was stable in the temperature range from room temperature to 80 °C because of the same temperature dependence of the current-voltage (I-V) characteristics. In addition, the temperature of the integrated hydrogen sensor was controlled by an integrated system consisting of a heater and a thermometer at any given temperature under severe weather conditions. © 2010 The Japan Society of Applied Physics.

    DOI: 10.1143/JJAP.49.024206

    Web of Science

    Scopus

    researchmap

  • Evaluation of the sensitivity of hydrogen sensors covered with polytetrafluoroethylene as a protective membrane for humidity

    Koji Fujii, Hirotsugu Inoue, Tomiharu Yamaguchi, Toshihiko Kiwa, Keiji Tsukada

    IEEJ Transactions on Sensors and Micromachines   130 ( 8 )   401 - 406   2010年

     詳細を見る

    記述言語:英語  

    Environmental factors such as dust adsorption effects and humidity generally result in drifts of the sensor output signal and lead tomalfunctions of the sensor and/or reduction in sensitivity. So a sensor package is necessary to protect hydrogen sensors in order to operate the sensors in an actual use environment. In this study, a Pt-FET hydrogen sensor covered with a polytetrafluoroethylene (PTFE) porous membrane was developed. The PTFE porous membrane with different pore sizes of 5 μm, 20 μm A and 30 μm was applied and the effects of humidity on sensor sensitivity were evaluated. The results indicate the effects of humidity on the sensitivity were reduced in the relative humidity range between 20% and 80% for the sensor with the 5-μm porous membrane. © 2010 The Institute of Electrical Engineers of Japan.

    DOI: 10.1541/ieejsmas.130.401

    Scopus

    researchmap

  • Development and evaluation of a Pt/Ti-FET-type hydrogen sensor

    Masatoshi Kariya, Kouhei Mizuhara, Tomiharu Yamaguchi, Toshihiko Kiwa, Shinsuke Kunitsugu, Keiji Tsukada

    IEEJ Transactions on Sensors and Micromachines   130 ( 8 )   407 - 411   2010年

     詳細を見る

    記述言語:英語  

    A novel gate-structure FET-type hydrogen sensor (Pt/Ti-FET) thathas an adhesion layer (Ti) between the catalytic metal (Pt) and the gate insulator was fabricated. The dependence of the response characteristics of the sensitivity and selectivity on the Ti thickness was investigated. The sensitivity showed dependence on Ti thickness, and higher sensitivity was obtained with a decrement in Ti thickness. In addition, the Pt/Ti-FET showed good selectivity against other gases (02, C2H6) compared with the Pt-FET. After annealing at 260°C for 30 min under 5 Pa in a vacuum, the Pt/Ti-FET showed different response characteristics from an as-depositedPt/Ti- FET. The annealed Pt/Ti-FETs with a thin Ti adhesion layer (below 10 nm) showed improved hydrogen sensitivity. In particular, the Ti5-nm sample of the Pt/Ti-FET sensor showed a higher hydrogen responsewhen exposed to 0.8% hydrogen gas (526.2 mV) compared to that of the Pt-FET sensor (415.7 mV). However, improvement in hydrogen sensitivity was not obtained in thick Ti samples. Additionally the annealed Pt/Ti-FET showed better selectivity against 0 2 than as-deposited Pt/Ti-FET. © 2010 The Institute of Electrical Engineers of Japan.

    DOI: 10.1541/ieejsmas.130.407

    Scopus

    researchmap

  • セキュアライフを支えるテラヘルツ波技術 テラヘルツ波ケミカル顕微鏡による非標識バイオセンシング

    紀和利彦

    Bio Industry   27 ( 10 )   14 - 19   2010年

     詳細を見る

  • Detectionofback-sidepitonaferrousplatebymagneticfluxleakagemethod with analyzingmagneticfieldvector

    Keiji Tsukada, Mitsuteru Yoshioka, Yoshihiko Kawasaki, Toshihiko Kiwa

    NDT & E International   43 ( 4 )   323 - 328   2010年

     詳細を見る

  • テラヘルツ波センシングプレート封入型検査セルの開発

    紀和利彦

    村田学術振興財団年報   ( 24 )   2010年

     詳細を見る

  • 低周波磁場を用いた金属疲労検査法の開発

    三宅康介, 吉岡光輝, 紀和利彦, 櫻本昌宏, 井上勝美, 塚田啓二

    日本磁気学会学術講演概要集   34th   2010年

     詳細を見る

  • スポット溶接評価用漏洩磁束探傷検査法

    吉岡光輝, 三宅康介, 紀和利彦, 平野佳伸, 松本光明, 塚田啓二

    日本非破壊検査協会講演大会講演概要集   2010   2010年

     詳細を見る

  • テラヘルツ波ケミカル顕微鏡によるpH分布評価応用

    近藤洋輔, 橋本陽平, 天満陽, 紀和利彦, 塚田啓二

    応用物理学会中国四国支部・日本物理学会中国支部・四国支部・日本物理教育学会中国四国支部支部学術講演会講演予稿集   2010   2010年

     詳細を見る

  • テラヘルツ波ケミカル顕微鏡のμ-TAS測定

    橋本陽平, 近藤洋輔, 紀和利彦, 川山巌, 斗内政吉, 塚田啓二

    応用物理学会学術講演会講演予稿集(CD-ROM)   71st   2010年

     詳細を見る

  • テラヘルツ波面制御デバイスの開発と評価

    別府慶治, 杉本武史, 紀和利彦, 塚田啓二

    応用物理学関係連合講演会講演予稿集(CD-ROM)   57th   2010年

     詳細を見る

  • テラヘルツ波面制御デバイスの開発

    別府慶治, 紀和利彦, 塚田啓二

    電気・情報関連学会中国支部連合大会講演論文集(CD-ROM)   61st   2010年

     詳細を見る

  • 触媒金属ゲートFETにおける応答メカニズムの解析

    井上大嗣, 片山文哉, 水原宏平, 紀和利彦, 塚田啓二

    センサ・マイクロマシンと応用システムシンポジウム(CD-ROM)   27th   2010年

     詳細を見る

  • FET型センサを用いた新型酸素センサの開発

    切明大輔, 片山文哉, 紀和利彦, 塚田啓二

    センサ・マイクロマシンと応用システムシンポジウム(CD-ROM)   27th   2010年

     詳細を見る

  • 保温断熱配管の磁気的非破壊検査方法の開発

    三宅康介, 吉岡光輝, 土井貴範, 紀和利彦, 塚田啓二, 河部俊英, 藤田理絵, 花口正典

    日本非破壊検査協会講演大会講演概要集   2010   2010年

     詳細を見る

  • テラヘルツ波ケミカル顕微鏡を用いた植物断面のpH分布イメージング

    近藤洋輔, 南祐治, 紀和利彦, 川山巌, 斗内政吉, 塚田啓二

    応用物理学関係連合講演会講演予稿集(CD-ROM)   57th   2010年

     詳細を見る

  • テラヘルツ波ケミカル顕微鏡の高感度化に向けたダブルパルス検出法の開発

    天満陽, 近藤洋輔, 紀和利彦, 塚田啓二

    応用物理学会中国四国支部・日本物理学会中国支部・四国支部・日本物理教育学会中国四国支部支部学術講演会講演予稿集   2010   2010年

     詳細を見る

  • HTS-SQUIDを用いた太陽電池の微分抵抗特性分布測定

    紀和利彦, 前田敏志, 三宅康介, 片岡伸夫, 塚本晃, 安達成司, 田辺圭一, 塚田啓二

    応用物理学会学術講演会講演予稿集(CD-ROM)   71st   2010年

     詳細を見る

  • 参照電極が不要な新型マイクロイオンセンサの開発

    小田和代, 井上豊崇, 紀和利彦, 塚田啓二

    電気学会全国大会講演論文集   2010 ( 3 )   2010年

     詳細を見る

  • 溶接部内部欠陥検出用磁気センサアレイプローブの開発

    三宅康介, 萬治寧大, 紀和利彦, 塚田啓二, 櫻本昌宏, 井上勝美

    電気学会全国大会講演論文集   2010 ( 2 )   2010年

     詳細を見る

  • プロトンポンピングゲート構造による電界効果トランジスタ型水素センサの高機能化

    山口富治, 假谷正敏, 紀和利彦, 塚田啓二

    Chemical Sensors   26 ( Supplement A )   2010年

     詳細を見る

  • プロトンポンピングゲート構造による電界効果トランジスタ型水素センサの高機能化

    山口富治, 假谷正敏, 紀和利彦, 塚田啓二

    電気化学会大会講演要旨集   77th   2010年

     詳細を見る

  • 白金薄膜の水素応答特性

    水原宏平, 片山文哉, 紀和利彦, 塚田啓二

    電気学会ケミカルセンサ研究会資料   CHS-10 ( 1-6.8-14 )   2010年

     詳細を見る

  • HTS-SQUIDを用いた磁気特性計測システムの開発

    前田敏志, 片岡伸夫, 紀和利彦, 塚本晃, 安達成司, 田辺圭一, 神鳥明彦, 塚田啓二

    応用物理学会学術講演会講演予稿集(CD-ROM)   71st   2010年

     詳細を見る

  • A novel ion sensor without a reference electrode

    Keiji Tsukada, Fumiyuki Kobayashi, Toyotaka Inoue, Toshihiko Kiwa

    Sensor Letters   7 ( 6 )   1163 - 1166   2009年12月

     詳細を見る

    記述言語:英語   出版者・発行元:AMER SCIENTIFIC PUBLISHERS  

    We developed an ion sensor with a novel structure that does not require a reference electrode. The structure consists of a double electrode comprising an outer electrode with a hole and an inner electrode, a polymeric ion-selective membrane, and the sensor body. The ion sensitivity of a potassium ion sensor, where the hole of the outer electrode was the same size as the inner electrode, was 55 mV/decade. The sensor exhibited increased sensitivity according to the increment of the hole size. The sensitivity was also dependent on the thickness of the outer membrane covering the outer electrode. These phenomena were examined using a membrane potential gradient simulation. Copyright © 2009 American Scientific Publishers All rights reserved Printed in the United States of America.

    DOI: 10.1166/sl.2009.1240

    Web of Science

    Scopus

    researchmap

  • Magnetic thickness gauge using a Fourier transformed eddy current technique

    Toshihiko Kiwa, Takayuki Hayashi, Yoshihiko Kawasaki, Hironobu Yamada, Keiji Tsukada

    NDT and E International   42 ( 7 )   606 - 609   2009年10月

     詳細を見る

    記述言語:英語   出版者・発行元:ELSEVIER SCI LTD  

    A Fourier-transformed eddy current (FTEC) technique has been proposed and developed. This technique employs Fourier transformation analysis to analyze pulsed eddy current signals measured by magnetoresistive sensors. The advantage of this technique is that the intrinsic response, Gamp (f), of a sample material can be extracted without it being affected by the characteristics of the measurement systems. Aluminum plates with an area of 100 mm × 100 mm and various thicknesses were used as test samples. We examined the relationship between the thickness of the sample and the frequency, when Gamp (f)'s reached 90% of the maximum magnitude. The results indicate that FTEC can be used for non-contact measurements of conductive materials. We also evaluated lift-off effects for Gamp (f) for 1- and 5-mm-thick samples. The deviations of the frequencies for the 90% response were 453.386 ± 14.37 and 99.789 ± 4.13 Hz for the 1- and 5-mm-thick samples, respectively. This result indicates that the lift-off effect was reduced by the FTEC analysis. © 2009 Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.ndteint.2009.04.003

    Web of Science

    Scopus

    researchmap

  • Non-contact thickness gauge for conductive aterials using HTS SQUID system

    Toshihiko Kiwa, Hideaki Tahara, Etsuro Miyake, Hironobu Yamada, Keiji Tsukada

    IEEE Transactions on Applied Superconductivity   19 ( 3 )   801 - 803   2009年6月

     詳細を見る

    記述言語:英語   出版者・発行元:IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC  

    Eddy current testing using high-Tc superconductive (HTS) superconducting quantum interference devices (SQUID), was developed to realize non-contact thickness gauge measurement of conductive materials, due to their high-sensitivity to magnetic fields generated by eddy currents. A HTS SQUID pulsed eddy current system with Fourier transform analysis is proposed and demonstrated. Aluminum plates (10 × 10 mm) with thicknesses in the range of 1 to 10 mm were used as test samples. The intrinsic responses Ga(f) of the samples were successfully extracted. The slopes of these responses were estimated by linear fitting, and plotted as a function of sample thickness. The Ga(f) slopes decrease with increasing thickness of the test samples. The analysed data suggests that this system can be used as a non-contact thickness gauge for conductive materials. © 2009 IEEE.

    DOI: 10.1109/TASC.2009.2019196

    Web of Science

    Scopus

    researchmap

  • Magnetic image detection of the stainless-steel welding part inside a multi-layered tube structure

    Takayuki Hayashi, Yoshihiko Kawasaki, Hironobu Yamada, Toshihiko Kiwa, Masaji Tamazumi, Keiji Tsukada

    NDT and E International   42 ( 4 )   308 - 315   2009年6月

     詳細を見る

    記述言語:英語   出版者・発行元:ELSEVIER SCI LTD  

    The stainless-steel welding part inside a multi-layered tube was successfully detected using low-frequency magnetic imaging. The magnetic images were obtained by the developed measurement system, consisting of an exposure coil, magnetoresistive (MR) sensor, lock-in amplifier, x-y stage, revolving stage with a horizontal level stage and personal computer. To expose the magnetic field to a wide area of the stainless-steel sample, the radius of the exposure coil was made comparable to the sample size. The MR sensor measured the vector components of the magnetic field generated from the sample within the range of low frequencies between 50 Hz and 1 kHz. A cylindrical stainless-steel sample was fabricated as a tube by rolling a stainless-steel sheet and welding each edge using arc welding with argon as shielding gas. The normal components (Bz) and tangential components (Bx and By) to the sample surface were measured by scanning the MR sensor on the sample surface and the magnetic characteristics of each of the component images were documented. As a result, the difference in permeability between the weld area and the base material was successfully visualized as magnetic images. © 2008 Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.ndteint.2008.12.006

    Web of Science

    Scopus

    researchmap

  • Highly sensitive measurement of moisture content using HTS-SQUID

    Keiji Tsukada, Toshihiko Kiwa, Hideaki Tahara, Etsuro Miyake, Hironobu Yamada, Akira Tsukamoto, Akihiko Kandori

    IEEE Transactions on Applied Superconductivity   19 ( 3 )   878 - 881   2009年6月

     詳細を見る

    記述言語:英語   出版者・発行元:IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC  

    We developed a highly sensitive magnetic system for measuring moisture content using an HTS-SQUID sensor. The system consists mainly of an exposure coil, a Dewar flask containing HTS-SQUID immersed in liquid nitrogen, a cancellation coil, a lock-in amplifier, magnetically shielded box, and FLL circuit. The cancellation coil was used to eliminate the applied magnetic field at the sensor position, and then a cancellation ratio of more than -40 dB was obtained. By the high performance, the subject can be exposed to a powerful magnetic field strength in the order of μT, and a weak magnetic signal of less than tens of pT from the subject can be detected. Using a magnetic vector analysis technique, more precise measurement of moisture content is realized. © 2009 IEEE.

    DOI: 10.1109/TASC.2009.2019659

    Web of Science

    Scopus

    researchmap

  • Measurement of pH in fluidic chip using a terahertz chemical microscope

    Toshihiko Kiwa, Shohei Oka, Yuji Minami, Iwao Kawayama, Masayoshi Tonouchi, Keiji Tsukada

    IEEJ Transactions on Sensors and Micromachines   129 ( 7 )   221 - 224   2009年

     詳細を見る

    記述言語:英語  

    A terahertz chemical microscope (TCM) has been developed to visualize the chemical concentration of solutions in fluidic chips. Chemical potential-terahertz transducers were newly developed and applied to the bottom surfaces of the flow channels. When femtosecond laser pulses hit the transducers, terahertz waves are radiated from them. Since the amplitude of terahertz waves can be related to the chemical potential on the surface of the device, the distribution of chemical reactions on the surface can be visualized by scanning the laser on the device. Here, we report the demonstration of mapping of pH values using TCM with a spatial resolution of less than 1 mm. The pH distribution of the flow channels filled with 0.01 M NaOH and HC1 was successfully visualized. In addition, the neutralization process was monitored. © 2009 The Institute of Electrical Engineers of Japan.

    DOI: 10.1541/ieejsmas.129.221

    Scopus

    researchmap

  • Temperature control and packaging optimization of the integrated hydrogen sensor

    Kousuke Tsubota, Toshihiko Kiwa, Hironobu Yamada, Tomiharu Yamaguchi, Yohei Kondo, Hirofumi Imajo, Tsutomu Hondo, Tunetoshi Maehara, Tadayoshi Yamamoto, Keiji Tsukada

    IEEJ Transactions on Sensors and Micromachines   129 ( 9 )   2 - 282   2009年

     詳細を見る

    記述言語:英語  

    An integrated sensor chip combining a heater for temperature control and a diode for temperature monitoring was fabricated and its characteristics evaluated. Furthermore, a new packaging structure with a gas permeable film and sensor chip attached to the glass to improve the heat efficiency were developed. Using this packaging structure, the optimum working conditions and protection for the sensor chip were realized. The features of the diode were suffïcient to verify the sensor temperature. In terms of the value of heat efficiency per power consumption, we succeeded in advancing its values by about 15% compared to the glassless type. Furthermore, the time response curves for the sensor temperature and power consumption of the heater were measured. The thermal control System consists of a heater and the diode was successfully utilized to maintain the intended temperature. The heat efficiency was improved by attaching a glass and this System was found to be useful for the PPG-FET type hydrogen sensor. ©; 2009 The Institute of Electrical Engineers of Japan.

    DOI: 10.1541/ieejsmas.129.278

    Scopus

    researchmap

  • Hydrogen selectivity of a proton-pumping gate FET hydrogen sensor in an AC modulation mode

    Tomiharu Yamaguchi, Masanori Takisawa, Toshihiko Kiwa, Hironobu Yamada, Keiji Tsukada

    IEEJ Transactions on Sensors and Micromachines   129 ( 4 )   110 - 114   2009年

     詳細を見る

    記述言語:英語  

    The response characteristics of a proton pumping gate FET (PPG-FET) with a triple layer gate structure (Pd/proton conducting polymer/Pt) to various gases were investigated. Two kinds of hydrogen response signals (DC and AC) were obtained from the PPG-FET when the AC bias voltage was applied between the gate electrodes of the PPG-FET. The DC signals showed high hydrogen sensitivities and the sensitivities were about -30 mV/decade. Additionally, the AC signal decreased by 10 mV with increase in the hydrogen concentration from 100 ppm to 10%. Whereas the DC signals decreased slightly with increasing oxygen concentration, the oxygen response was much smaller than the DC hydrogen sensitivities. In contrast, the AC signal hardly responded to oxygen. This is because a proton conducting polymer layer prevents the movement of oxygen ions. Additionally, the proton pumping gate FET showed good selectivity against other gases (methane, ethane, ammonia, and methanol). These results clarify the high hydrogen sensitivity of the PPG-FET in an AC modulation mode. © 2009 The Institute of Electrical Engineers of Japan.

    DOI: 10.1541/ieejsmas.129.110

    Scopus

    researchmap

  • テラヘルツ波ケミカル顕微鏡を用いたアビジン-ビオチン結合の検出

    近藤洋輔, 南祐治, 紀和利彦, 川山巌, 斗内政吉, 塚田啓二

    応用物理学会学術講演会講演予稿集   70th ( 3 )   2009年

     詳細を見る

  • プロトンポンピングゲートFETをベースとした集積化水素ガスセンサの開発

    山口富治, 坪田公輔, 山田博信, 紀和利彦, 塚田啓二, 近藤洋平, 今城啓文, 本藤勉, 前原経利, 山本忠義

    電気学会全国大会講演論文集   2009 ( 3 )   2009年

     詳細を見る

  • 低周波磁気ベクトル解析による鉄鋼板厚みの非破壊検出方法

    林孝之, 林孝之, 川崎喜彦, 山田博信, 紀和利彦, 井上勝美, 塚田啓二

    日本非破壊検査協会大会講演概要集   2009   2009年

     詳細を見る

  • 印加磁場直交配置型HTS-SQUID非破壊検査装置の開発

    紀和利彦, 三宅悦朗, 山田博信, 塚本晃, 塚田敬二

    応用物理学会学術講演会講演予稿集   70th ( 1 )   2009年

     詳細を見る

  • 低周波磁場を用いた漏洩磁束探傷試験

    吉岡光輝, 川崎喜彦, 紀和利彦, 塚出啓二

    電気・情報関連学会中国支部連合大会講演論文集(CD-ROM)   60th   2009年

     詳細を見る

  • 高温超伝導SQUIDを用いたフーリエ型パルス渦流探傷法による金属板の欠陥検出

    三宅悦朗, 田原秀哲, 山田博信, 紀和利彦, 塚田啓二

    応用物理学関係連合講演会講演予稿集   56th ( 1 )   2009年

     詳細を見る

  • Pt/Ti二層ゲートFET型水素センサの空気雰囲気での水素応答特性

    假谷正敏, 山口富治, 紀和利彦, 山田博信, 塚田啓二, 國次真輔

    電気学会全国大会講演論文集   2009 ( 3 )   2009年

     詳細を見る

  • ガス透過膜の水素センサへの適用

    藤井浩二, 山口富治, 紀和利彦, 山田博信, 塚田啓二

    電気学会全国大会講演論文集   2009 ( 3 )   2009年

     詳細を見る

  • テラヘルツ波ケミカル顕微鏡を用いた固定化酵素反応イメージング

    南祐治, 岡昇平, 紀和利彦, 川山巌, 斗内政吉, 塚田啓二

    応用物理学関係連合講演会講演予稿集   56th ( 3 )   2009年

     詳細を見る

  • HTS-SQUIDを用いた直交磁場印加型非破壊検査システムの開発

    三宅悦朗, 紀和利彦, 塚田啓二, 塚本晃

    低温工学・超電導学会講演概要集   81st   2009年

     詳細を見る

  • 参照電極が不要な新型マイクロイオンセンサの開発

    井上豊崇, 小田和代, 山田博信, 紀和利彦, 塚田啓二

    Chemical Sensors   25 ( Supplement B )   2009年

     詳細を見る

  • フーリエ変換過流探傷法による鉄鋼板厚の非破壊検出

    林孝之, 林孝之, 川崎喜彦, 吉岡光輝, 山田博信, 紀和利彦, 井上勝美, 塚田啓二

    日本磁気学会学術講演概要集   33rd   2009年

     詳細を見る

  • 磁気を用いたモルタルの水分含有量の測定方法

    片岡伸夫, 増田康孝, 山田博信, 紀和利彦, 尾藤良孝, 塚田啓二

    日本磁気学会学術講演概要集   33rd   2009年

     詳細を見る

  • Analysis of response mechanism of a proton-pumping gate FET hydrogen gas sensor in air

    T. Yamaguchi, M. Takisawa, T. Kiwa, H. Yamada, K. Tsukada

    Sensors and Actuators, B: Chemical   133 ( 2 )   538 - 542   2008年8月

     詳細を見る

    記述言語:英語   出版者・発行元:ELSEVIER SCIENCE SA  

    Two different types of hydrogen response signals (DC and AC) of a proton-pumping gate FET with triple layer gate structure (Pd/proton conducting polymer/Pt) were obtained. The proton-pumping gate FET showed good selectivity against other gases (CH4, C2H6, NH3, and O2). For practical use, the hydrogen response characteristics of the proton-pumping gate FET were investigated in air (a gaseous mixture of oxygen and nitrogen). The proton-pumping gate FET showed different hydrogen response characteristics in nitrogen as well as in air, despite the lack of oxygen interference independently. To clarify the response mechanism of the proton-pumping gate FET, a hydrogen response measurement was performed, using a gas flow system and electrochemical impedance spectroscopy. Consequently, the difference in response between nitrogen and air was found to be due to the hydrogen dissociation reaction and the interference with the proton transfer caused by the adsorbed oxygen on the upper Pd gate electrode. © 2008 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.snb.2008.03.021

    Web of Science

    Scopus

    researchmap

  • Chemical sensing plate with a laser-terahertz monitoring system. 国際誌

    Toshihiko Kiwa, Junichi Kondo, Shohei Oka, Iwao Kawayama, Hironobu Yamada, Masayoshi Tonouchi, Keiji Tsukada

    Applied optics   47 ( 18 )   3324 - 7   2008年6月

     詳細を見る

    記述言語:英語   出版者・発行元:OPTICAL SOC AMER  

    A new type of laser-terahertz emission system for noncontact investigations of chemical solutions has been developed. The system monitors terahertz emission from a sensing plate, which consists of silicon oxide and silicon thin film layers on a sapphire substrate. Sensing of chemical solutions with pH values between 1.68 and 10.01 was demonstrated. The amplitude of the terahertz emission from the sensing plate increased with increasing pH value. This change in the amplitude was caused by a change in the depletion layers of the silicon thin film when protons were adsorbed on the surface of the sensing plate. This study demonstrates that full noncontact monitoring of chemical solutions is possible using the laser-terahertz emission system.

    DOI: 10.1364/AO.47.003324

    Web of Science

    Scopus

    PubMed

    researchmap

  • Magnetic measurement of the moisture content in soil: Diamagnetic measurement with the presence of ferromagnetic material

    Keiji Tsukada, Yasutaka Masuda, Yudai Ishihara, Toshihiko Kiwa

    Applied Physics Express   1 ( 6 )   0670081 - 0670083   2008年6月

     詳細を見る

    記述言語:英語   出版者・発行元:JAPAN SOC APPLIED PHYSICS  

    To measure the moisture content of soil, we developed a method that measures the magnetic field generated when the primary magnetic field Is exposed. Soil contains two different types of materials: water as a diamagnetic material and Iron sand as a ferromagnetic material. Water shows a constant phase shift from the primary magnetic field as well as a frequency dependence of the magnetic field strength, and iron sand showed the opposite characteristics. Using these magnetic properties, a moisture content signal was extracted, even with Interference of the iron sand. © 2008 The Japan Society of Applied Physics.

    DOI: 10.1143/APEX.1.067008

    Web of Science

    Scopus

    researchmap

  • Magneto-electrical cyclic voltammetry for visualization of current distribution in the electrolyte

    K. Tsukada, F. Kobayashi, H. Arai, T. Kiwa

    Electrochemistry Communications   10 ( 6 )   938 - 942   2008年6月

     詳細を見る

    記述言語:英語   出版者・発行元:ELSEVIER SCIENCE INC  

    Cyclic voltammetry is widely used in electrochemistry. To visualize the current distribution in the electrolyte, we developed a two-dimensional magnetic imaging system, combining the electric measurement component used in conventional cyclic voltammetry with a pair of MR (magnetic resistive) sensors to detect the x- and y-magnetic components. The resulting system allows simultaneous measurement of the electronic current of the working electrode and the magnetic field resulting from the transport of ions by migration in the bulk electrolyte. The current distribution in the electrolyte was reconstructed using the magnetic field strength data obtained at multiple points. Consequently, we could observe the change in current distribution when changing the length of the working electrode immersed in the electrolyte. © 2008 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.elecom.2008.04.020

    Web of Science

    Scopus

    researchmap

  • Difference in the detection limits of flaws in the depths of multi-layered and continuous aluminum plates using low-frequency eddy current testing

    Hironobu Yamada, Teruki Hasegawa, Yudai Ishihara, Toshihiko Kiwa, Keiji Tsukada

    NDT and E International   41 ( 2 )   108 - 111   2008年3月

     詳細を見る

    記述言語:英語   出版者・発行元:ELSEVIER SCI LTD  

    We examined the difference in the detection limits of flaws in the depths of multi-layered and continuous aluminum plates using low-frequency eddy current testing. The detection limits were measured by using a magneto-resistive sensor. Comparing the frequency of an applied magnetic field, the detection limit at 50 Hz is deeper than that at 1 kHz. Comparing the sample structure, the detection limit in the multi-layered samples is deeper than that in the continuous samples. These results are likely due to the differences in the skin depth and conductivity of the sample. © 2007 Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.ndteint.2007.08.004

    Web of Science

    Scopus

    researchmap

  • Detection of the weak magnetic properties change of stainless-steel welding parts by low frequency magnetic imaging

    Takayuki Hayashi, Hironobu Yamada, Toshihiko Kiwa, Keiji Tsukada, Masaji Tamazumi

    Journal of Applied Physics   103 ( 7 )   07E923   2008年

     詳細を見る

    記述言語:英語   出版者・発行元:AMER INST PHYSICS  

    Differences in weld quality resulting from variations in welding conditions were detected via low frequency magnetic imaging. This magnetic imaging was obtained using a recently developed measurement system, consisting of an exposure coil, a magnetoresistive (MR) sensor, and a lock-in amplifier. A wide area of stainless-steel sample was exposed to the magnetic field via an induction coil, and the MR sensor measured the generated magnetic field from the sample. The frequency of the magnetic field ranged from 20 Hz to 1 kHz. A cylindrical stainless-steel sample was fabricated by rolling a stainless-steel sheet and welding each edge by an arc welder with argon gas, while the welding condition was changed by controlling the argon gas flow. The magnitude and phase shift of the generated magnetic field from the sample was measured by scanning the MR sensor on the sample surface. The change in magnetic properties caused by the welding condition change was successfully imaged. © 2008 American Institute of Physics.

    DOI: 10.1063/1.2837628

    Web of Science

    Scopus

    researchmap

  • Redox reactions of enzymes measured by terahertz chemical microscope

    Toshihiko Kiwa, Jyunichi Kondo, Iwo Kawayama, Masayoshi Tonouchi, Keiji Tsukada

    33rd International Conference on Infrared and Millimeter Waves and the 16th International Conference on Terahertz Electronics, 2008, IRMMW-THz 2008   594 - +   2008年

     詳細を見る

    記述言語:英語   出版者・発行元:IEEE  

    A terahertz chemical microscope (TCM) was proposed and developed to measure redox reaction of enzymes. TCM utilize the sensing plate which can measure the surface potential changes at the laser illuminated area by detecting the terahertz waves generated from the plate. An immobilized urease was applied to the plate and the redox reaction with the urea in the buffer solution was demonstrated. @IEEE.

    DOI: 10.1109/ICIMW.2008.4665724

    Web of Science

    Scopus

    researchmap

  • テラヘルツ波ケミカル顕微鏡による流路内化学濃度分布イメージング

    岡昇平, 近藤純一, 紀和利彦, 川山巌, 斗内政吉, 塚田啓二

    応用物理学関係連合講演会講演予稿集   55th ( 3 )   2008年

     詳細を見る

  • 磁場計測による電解質溶液中の電流評価

    小林史幸, 新井裕之, 萬治寧大, 紀和利彦, 塚田啓二

    電気学会全国大会講演論文集   2008 ( 2 )   2008年

     詳細を見る

  • 低周波磁気を用いたステンレス多層配管内の溶接部の新しい非破壊検出方法

    林孝之, 林孝之, 川崎喜彦, 山田博信, 紀和利彦, 玉積正司, 塚田啓二

    日本非破壊検査協会大会講演概要集   2008   2008年

     詳細を見る

  • 極低周波磁気を用いた鉄板溶接部の内部欠陥検査法

    長谷川照起, 山田博信, 紀和利彦, 井上勝美, 玉積正司, 塚田啓二

    日本非破壊検査協会大会講演概要集   2008   2008年

     詳細を見る

  • パルス渦流探傷を用いたリフトオフの影響を受けない金属板厚み検査法の開発

    川崎喜彦, 林孝之, 山田博信, 紀和利彦, 塚田啓二

    日本磁気学会学術講演概要集   32nd   2008年

     詳細を見る

  • 低周波磁気検査によるステンレス多層配管中の溶接部の検出

    林孝之, 林孝之, 川崎喜彦, 山田博信, 紀和利彦, 玉積正司, 塚田啓二

    日本磁気学会学術講演概要集   32nd   2008年

     詳細を見る

  • HTS-SQUID渦流探傷法による金属厚み検査装置の開発

    紀和利彦, 田原秀哲, 山田博信, 塚田啓二

    応用物理学会学術講演会講演予稿集   69th ( 1 )   2008年

     詳細を見る

  • 各種ガスによるプロトンポンピングゲート水素センサのゲート部のインピーダンス変化

    滝澤正教, 山口富治, 紀和利彦, 山田博信, 塚田啓二

    電気学会全国大会講演論文集   2008 ( 3 )   2008年

     詳細を見る

  • 低周波磁気イメージングシステムによるステンレス溶接欠陥の非破壊検査

    林孝之, 林孝之, 山田博信, 紀和利彦, 玉積正司, 塚田啓二

    電気学会全国大会講演論文集   2008 ( 2 )   2008年

     詳細を見る

  • フーリエ型パルス渦流探傷法による金属板厚検査法の開発

    紀和利彦, 川崎喜彦, 林孝之, 山田博信, 塚田啓二

    日本非破壊検査協会大会講演概要集   2008   2008年

     詳細を見る

  • 磁気による砂の水分含有量の測定方法

    増田康孝, 紀和利彦, 塚田啓二

    日本磁気学会学術講演概要集   32nd   2008年

     詳細を見る

  • 砂の水分量の新しい磁気計測方法

    塚田啓二, 増田康孝, 石原雄大, 紀和利彦

    応用物理学関係連合講演会講演予稿集   55th ( 1 )   2008年

     詳細を見る

  • 交流変調時におけるプロトンポンピングゲートFET型水素センサの応答特性評価

    山口富治, 滝澤正教, 紀和利彦, 山田博信, 塚田啓二

    電気学会全国大会講演論文集   2008 ( 3 )   2008年

     詳細を見る

  • 高温超伝導SQUIDを用いた高感度水分含有量測定システムの開発

    田原秀哲, 三宅悦朗, 窪田篤, 紀和利彦, 山田博信, 塚田啓二

    応用物理学関係連合講演会講演予稿集   55th ( 1 )   2008年

     詳細を見る

  • 低周波渦流探傷検査システムの鉄板溶接部評価への適用

    長谷川照起, 石原雄大, 林孝之, 紀和利彦, 山田博信, 塚田啓二

    電気学会全国大会講演論文集   2008 ( 2 )   2008年

     詳細を見る

  • テラヘルツ波ケミカル顕微鏡によるガス選択検出手法の開発

    小野坂宏之, 紀和利彦, 塚田啓二, 川山巌, 斗内政吉

    電気学会全国大会講演論文集   2008 ( 3 )   2008年

     詳細を見る

  • THz波ケミカル顕微鏡を用いた酵素反応検出

    紀和利彦, 川山巌, 斗内政吉, 塚田啓二

    応用物理学会学術講演会講演予稿集   69th ( 3 )   2008年

     詳細を見る

  • THz波ケミカル顕微鏡を用いたガス触媒評価手法の開発

    紀和利彦, 小野坂宏之, 川山巌, 山田博信, 斗内政吉, 塚田啓二

    応用物理学関係連合講演会講演予稿集   55th ( 3 )   2008年

     詳細を見る

  • A terahertz chemical microscope to visualize chemical concentrations in microfluidic chips

    Toshihiko Kiwa, Shohei Oka, Junichi Kondo, Iwao Kawayama, Hironobu Yamada, Masayoshi Tonouchi, Keiji Tsukada

    Japanese Journal of Applied Physics, Part 2: Letters   46 ( 41-44 )   L1052 - L1054   2007年11月

     詳細を見る

    記述言語:英語   出版者・発行元:JAPAN SOC APPLIED PHYSICS  

    Here, a new type of terahertz chemical microscope (TCM) is proposed and developed, and the first demonstration of imaging the chemical concentration in fluid channels is reported. Fluid samples flow through channels possessing a semiconductor sensing plate as a bottom wall. Terahertz (THz) waves are radiated from the sensing plate as a result of femtosecond laser illumination. Because the amplitude of the THz radiation depends on the concentration of ions adsorbed on the surface of the plate, the ion distribution in the fluid channels can be visualized by scanning the laser across the plate. An image showing separated solutions with two different proton concentrations is successfully observed as the first demonstration of this instrument. © 2007 The Japan Society of Applied Physics.

    DOI: 10.1143/JJAP.46.L1052

    Web of Science

    Scopus

    researchmap

  • A proton pumping gate field-effect transistor for a hydrogen gas sensor

    Keiji Tsukada, Tomiharu Yamaguchi, Toshihiko Kiwa

    IEEE Sensors Journal   7 ( 9 )   1268 - 1269   2007年9月

     詳細を見る

    記述言語:英語   出版者・発行元:IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC  

    A proton pumping field-effect transistor (FET), consisting of a triple layer gate structure of a Pd/proton conducting polymer/Pt, has been developed. The hydrogen sensitivity was controlled by the bias change between Pt and Pd. Furthermore, two kinds of methods for the readout of DC and AC modulation can be achieved. According to the decrement of the bias frequency, the modulated output was increased. This characteristic realizes a gas sensor with a self-check function. © 2007 IEEE.

    DOI: 10.1109/JSEN.2007.901268

    Web of Science

    Scopus

    researchmap

  • Fourier-transformed eddy current technique to visualize cross-sections of conductive materials

    Toshihiko Kiwa, Tomoaki Kawata, Hironobu Yamada, Keiji Tsukada

    NDT and E International   40 ( 5 )   363 - 367   2007年7月

     詳細を見る

    記述言語:英語   出版者・発行元:ELSEVIER SCI LTD  

    A pulsed eddy current NDE system is useful for detecting deep flaws in conductive materials. We have developed a pulsed eddy current NDE system using a magneto-resistive sensor. The induction coil generates a pulsed magnetic field which has a frequency component between 0 and 3 kHz, and a maximum amplitude of about 4 μ T. Aluminum plates with flaws at depths of 1 and 2 mm were measured, and the intrinsic frequency responses of the plates were obtained using a proposed Fourier transformation method. Cross-sectional images of the samples could then be directly constructed from the intrinsic responses. We also demonstrated estimation of quantitative values for the depths of flaws. The estimated depth was well defined for a sample with a flaw at a depth of 2 mm. The estimated value was slightly different for a sample with a flaw at a depth of 1 mm due to lack of frequency components above 3 kHz. These results indicate that the proposed system is a very promising tool for NDE tomography. © 2007 Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.ndteint.2007.01.006

    Web of Science

    Scopus

    researchmap

  • Magnetic measurement of moisture content of grain

    Keiji Tsukada, Toshihiko Kiwa

    IEEE Transactions on Magnetics   43 ( 6 )   2683 - 2685   2007年6月

     詳細を見る

    記述言語:英語   出版者・発行元:IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC  

    We developed a technique to magnetically measure the moisture content of grain. The measurement method developed consists of an exposure magnetic coil, and a magnetic resistance sensor. When the grain is exposed to alternating magnetic fields of low frequency, a secondary magnetic field generated from the grain is observed. Two kinds of grain with different water absorption abilities (nonglutinous rice and glutinous rice) were measured. The secondary magnetic field strength of the grain increased incrementally with the moisture content. The experimental result indicated the applicability of the developed magnetic measurement method for nondestructive moisture measurement. © 2007 IEEE.

    DOI: 10.1109/TMAG.2007.892853

    Web of Science

    Scopus

    researchmap

  • Detection of photomixing signals with a YBCO Josephson junction coupled to a coplanar waveguide

    Iwao Kawayama, Ryuhei Kinjo, Toshihiko Kiwa, Hironaru Murakami, Masayoshi Tonouchi

    IEEE Transactions on Applied Superconductivity   17 ( 2 )   321 - 323   2007年6月

     詳細を見る

    記述言語:英語   出版者・発行元:IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC  

    We have fabricated a generation and detection system of photomixing signals using a photomixing technique and a Josephson junction detector. Up to now, an electromagnetic wave generated by a heterodyne mixing of two lasers was emitted from an antenna, and irradiated to a Josephson junction. In this study, we have developed the system, and the photomixing signal was introduced into a coaxial cable and a coplanar wave guide coupled to a Josephson junction. This structure is more suitable for device application since it can easily be integrated into electronic devices. With this system we can clearly observed photomixing signals from 16 GHz to 95 GHz using a uni-traveling-carrier photodiode as a photomlxer as well as signals in the range of 14 GHz to 50 GHz using an InGaAs PIN photodiode. © 2007 IEEE.

    DOI: 10.1109/TASC.2007.898106

    Web of Science

    Scopus

    researchmap

  • Oxygen interference mechanism of platinum-FET hydrogen gas sensor

    T. Yamaguchi, T. Kiwa, K. Tsukada, K. Yokosawa

    Sensors and Actuators, A: Physical   136 ( 1 )   244 - 248   2007年5月

     詳細を見る

    記述言語:英語   出版者・発行元:ELSEVIER SCIENCE SA  

    This paper reports the effect of oxygen in air on a Pt-FET hydrogen sensor. The output voltage change of the Pt-FET had good linearity to the logarithm of hydrogen concentration in nitrogen. The slope of the linear curve is -26.4 mV/decade, which is close to the calculated value of the Nernstian slope. This indicates the response mechanism of the Pt-FET sensor is based on the catalytic reaction on the Pt surface. However, the output voltage change of the Pt-FET was not proportional to the logarithm of hydrogen concentration in air due to adsorbed oxygen on the Pt surface. This indicates the water formation for the reaction of hydrogen and oxygen on the Pt surface is the main hydrogen response mechanism in air. © 2006 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.sna.2006.11.026

    Web of Science

    Scopus

    researchmap

  • Study on sub-THz signal input for superconducting electronic devices

    Iwao Kawayama, Yasushi Doda, Ryuhei Kinjo, Toshihiko Kiwa, Hironaru Murakami, Masayoshi Tonouchi

    IEICE Transactions on Electronics   E90-C ( 3 )   588 - 594   2007年3月

     詳細を見る

    記述言語:英語   出版者・発行元:IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG  

    Development of ultrafast optical interfaces that can operate in sub-terahertz region is important to apply superconducting electronic devices to the high-end systems. We have performed several fundamental researches to realize the ultrafast optical input interface for superconducting electronic devices. Firstly, we observed optical response of amorphous Ge thin films, and the results indicated that an amorphous Ge photoconductive switch could stably operate in a terahertz frequency range as an optical-to-electrical signal converter in the low-temperature region below Tc of YBCO. Next, we have fabricated optical-to-electrical signal conversion system with photomixing technique, and we have demonstrated the generation and the detection of high frequency signals over 50 GHz. Finally, we have observed optical responses of a Josephson vortex flow transistor under irradiation of femtosecond laser pulses, and the results suggeste that the device has high potential as an optical interface. Copyright © 2007 The Institute of Electronics, Information and Communication Engineers.

    DOI: 10.1093/ietele/e90-c.3.588

    Web of Science

    Scopus

    researchmap

  • Laser-terahertz emission from the chemical sensing plate

    Toshihiko Kiwa, Junichi Kondo, Shohei Oka, Iwao Kawayama, Hironobu Yamada, Masayoshi Tonouchi, Keiji Tsukada

    2007 JOINT 32ND INTERNATIONAL CONFERENCE ON INFRARED AND MILLIMETER WAVES AND 15TH INTERNATIONAL CONFERENCE ON TERAHERTZ ELECTRONICS, VOLS 1 AND 2   Vol. 1 pp. 285-286   280 - +   2007年

     詳細を見る

    記述言語:英語   出版者・発行元:IEEE  

    A new type of sensing system to measure the concentration of the protons in the solutions by means of the laser-terahertz emission and detection was proposed and developed. The simple layered structures of SiO2/Si thin films on a sapphire substrate were prepared as a chemical sensing plate. The system measure the amplitude of the terahertz emission from the depletion layer of SiO2/Si interface by irradiating the femtosecond laser pulses with the center wavelength of 790 nm. The solution was contacted with the SiO2 surface and the Si thin film layer was electrically grounded. An Ag/AgCl reference electrode was used to control the potential of the solution. When the proton was adsorbed on the surface of the plate, the surface electric dipole was formed at the surface, which changes the local field of the depletion layer. Thus the peak amplitude of terahertz emission was changed depending on the number of the proton adsorbed on the surface of the plate. Actually, we demonstrated that the peak amplitude of terahertz; emission from the sensing plate increased by increasing the pH values of the test solution when the bias voltage of the solution was 0 V. (pH values indicate the concentration of the proton in the solution) and the sensitivity was about 31 mu V/pH.

    Web of Science

    researchmap

  • Low-frequency magnetic field detection for metal sensing

    Toshihiko Kiwa, Tomoaki Kawata, Keiji Tsukada

    International Journal of Applied Electromagnetics and Mechanics   25 ( 1-4 )   447 - 451   2007年

     詳細を見る

    記述言語:英語   出版者・発行元:IOS PRESS  

    A new type of magnetic field detection system, which can operate at a frequency below 1 kHz, is proposed and developed. The system consists of a 40-turn-coil to generate the magnetic field and a magneto resistive sensor to detect both the amplitude and the phase signal of the magnetic field induced by eddy-current and magnetization of the samples. The magnetic field detection of ferro- and non-magnetic samples using the system is demonstrated and discussed. © 2007 - IOS Press and the authors. All rights reserved.

    DOI: 10.3233/jae-2007-745

    Web of Science

    Scopus

    researchmap

  • Hydrogen response mechanism of a proton pumping gate FET gas sensor

    Keiji Tsukada, Tomiharu Yamaguchi, Toshihiko Kiwa, Hironobu Yamada

    Proceedings of IEEE Sensors   1326 - 1329   2007年

     詳細を見る

    記述言語:英語   出版者・発行元:IEEE  

    We developed a new type hydrogen sensor for a proton pumping gate FET with a triple layer of Pd / proton conducting polymer / Pt. Compared with conventional type FET with a single catalytic metal gate, the selectivity was improved. Furthermore, two different output signals of DC and AC modulation were obtained. According to increments of the upper gate voltage to a lower gate, the sensitivity was increased. When modulation voltage was added to the upper gate voltage, AC modulation output was obtained. The response mechanism of the new type FET was investigated using several hydrogen gases and with modulation conditions. Consequently, the hydrogen response mechanism can be explained by a hydrogen dissociation reaction occurring at the upper gate, and the hydrogen gas and generated proton can pass through the proton conducting polymer, and finally an equilibrium hydrogen reaction occurs at the lower gate. These complex mechanisms can be controlled by the gate bias and modulation voltage. © 2007 IEEE.

    DOI: 10.1109/ICSENS.2007.4388655

    Web of Science

    Scopus

    researchmap

  • Laser-terahertz emission from the chemical sensing plate

    Toshihiko Kiwa, Junichi Kondo, Shohei Oka, Iwao Kawayama, Hironobu Yamada, Masayoshi Tonouchi, Keiji Tsukada

    IRMMW-THz2007 - Conference Digest of the Joint 32nd International Conference on Infrared and Millimetre Waves, and 15th International Conference on Terahertz Electronics   285 - 286   2007年

     詳細を見る

    記述言語:英語   出版者・発行元:IEEE  

    A new type of sensing system to measure the concentration of the protons in the solutions by means of the laser-terahertz emission and detection was proposed and developed. The simple layered structures of SiO2/Si thin films on a sapphire substrate were prepared as a chemical sensing plate. The system measure the amplitude of the terahertz emission from the depletion layer of SiO2/Si interface by irradiating the femtosecond laser pulses with the center wavelength of 790 nm. The solution was contacted with the SiO 2 surface and the Si thin film layer was electrically grounded. An Ag/AgCl reference electrode was used to control the potential of the solution. When the proton was adsorbed on the surface of the plate, the surface electric dipole was formed at the surface, which changes the local field of the depletion layer. Thus the peak amplitude of terahertz emission was changed depending on the number of the proton adsorbed on the surface of the plate. Actually, we demonstrated that the peak amplitude of terahertz emission from the sensing plate increased by increasing the pH values of the test solution when the bias voltage of the solution was 0 V. (pH values indicate the concentration of the proton in the solution) and the sensitivity was about 31 μV/pH.

    DOI: 10.1109/icimw.2007.4516500

    Web of Science

    Scopus

    researchmap

  • Laser-terahertz emission readout of chemical sensors

    T. Kiwa, J. Kondo, S. Oka, I. Kawayama, H. Yamada, M. Tonouchi, K. Tsukada

    TRANSDUCERS and EUROSENSORS '07 - 4th International Conference on Solid-State Sensors, Actuators and Microsystems   Vol. 2, p.1915-1918, 2007   1915 - 1918   2007年

     詳細を見る

    記述言語:英語   出版者・発行元:IEEE  

    A new type of laser-terahertz emission system for the non-contact investigation of the chemical solutions has been developed. This system monitors the terahertz emission from a sensing plate, which consists of a silicon oxide and a silicon thin film layers on the sapphire substrate. The sensing of chemical solutions with the pH value between 1.68 and 10.01 was demonstrated. The amplitude of terahertz emission from the sensing plate increased with increasing the pH value. This change in the amplitude was caused by the change of the depletion layers of the silicon thin film when protons adsorbed at the surface of the sensing plate. This result indicates that fully non-contact monitoring of chemical solutions can be possible using the laser-terahertz emission system. ©2007 IEEE.

    DOI: 10.1109/SENSOR.2007.4300533

    Web of Science

    Scopus

    researchmap

  • 低周波渦流探傷検査システムの金属溶接部評価への適用

    長谷川照起, 石原雄大, 林孝之, 山田博信, 紀和利彦, 塚田啓二

    電気学会基礎・材料・共通部門大会講演論文集(CD-ROM)   2007   2007年

     詳細を見る

  • FET型水素センサのガス選択性改善

    山口富治, 滝澤正教, 紀和利彦, 山田博信, 塚田啓二

    電気学会全国大会講演論文集   2007 ( 3 )   2007年

     詳細を見る

  • パルス渦流探傷によるフーリエ解析手法の開発

    紀和利彦, 河田知明, 山田博信, 塚田啓二

    電気学会全国大会講演論文集   2007 ( 2 )   2007年

     詳細を見る

  • プロトンポンピングゲート構造をもったFET型水素センサ

    塚田啓二, 山口富治, 紀和利彦, 山田博信

    電気学会全国大会講演論文集   2007 ( 3 )   2007年

     詳細を見る

  • プロトンポンピングゲートFET型水素ガスセンサの感応膜特性評価

    山口富治, 滝澤正教, 紀和利彦, 山口博信, 塚田啓二

    電気学会ケミカルセンサ研究会資料   CHS-07 ( 23-48 )   2007年

     詳細を見る

  • 電解質溶液中のイオン輸送現象の磁気的解析

    小林史幸, 新井裕之, 紀和利彦, 塚田啓二

    日本応用磁気学会学術講演概要集   31st   2007年

     詳細を見る

  • Pt-FET型水素センサの選択性評価

    中田章太, 山口富治, 紀和利彦, 山田博信, 塚田啓二

    電気学会全国大会講演論文集   2007 ( 3 )   2007年

     詳細を見る

  • 低周波磁気検査によるステンレス溶接の欠陥評価

    林孝之, 林孝之, 山田博信, 紀和利彦, 玉積正司, 塚田啓二

    日本応用磁気学会学術講演概要集   31st   2007年

     詳細を見る

  • テラヘルツ波を用いた非接触化学センサープレートの開発

    紀和利彦, 近藤純一, 岡昇平, 川山巌, 山田博信, 斗内政吉, 塚田啓二

    応用物理学関係連合講演会講演予稿集   54th ( 3 )   2007年

     詳細を見る

  • テラヘルツ波pHセンサーシステムの開発

    近藤純一, 岡昇平, 紀和利彦, 山田博信, 塚田啓二, 川山巌, 斗内政吉

    電気学会全国大会講演論文集   2007 ( 3 )   2007年

     詳細を見る

  • 電界効果型水素センサを用いた多点同時計測水素ガス拡散モニタ

    吉武剣, 坪井公輔, 山口富治, 山田博信, 紀和利彦, 塚田啓二

    電気学会ケミカルセンサ研究会資料   CHS-07 ( 23-48 )   2007年

     詳細を見る

  • 穀物水分量の新しい磁気計測方法

    塚田啓二, 紀和利彦

    応用物理学関係連合講演会講演予稿集   54th ( 1 )   2007年

     詳細を見る

  • 磁場計測を用いた新しい電気化学測定システムの開発

    新井裕之, 小林史幸, 紀和利彦, 塚田啓二

    電気学会基礎・材料・共通部門大会講演論文集(CD-ROM)   2007   2007年

     詳細を見る

  • 低周波磁気検査システムを用いた積層構造内部の欠陥評価

    山田博信, 石原雄大, 紀和利彦, 塚田啓二, 玉積正司

    電気学会全国大会講演論文集   2007 ( 1 )   2007年

     詳細を見る

  • 低周波磁場照射による水の磁気応答特性

    塚田啓二, 増田祐生, 紀和利彦

    応用物理学関係連合講演会講演予稿集   54th ( 1 )   2007年

     詳細を見る

  • AC magnetic properties of large volume of water - Susceptibility measurement in unshielded environment

    Keiji Tsukada, Toshihiko Kiwa, Yuuki Masuda

    Japanese Journal of Applied Physics, Part 2: Letters   45 ( 37-41 )   L1097 - L1099   2006年10月

     詳細を見る

    記述言語:英語   出版者・発行元:JAPAN SOC APPLIED PHYSICS  

    To investigate the effect of low-frequency magnetic-field exposure of a human body, the low-frequency AC magnetic property of a large volume of water was measured by low-frequency magnetic field exposure (from 50 Hz to 1.2 kHz). The results indicate that the AC magnetic property of water is due to diamagnetism in the low-frequency range. The phase between the main magnetic field and the generated magnetic field remained constant at about 180°. Results were not affected by conductivity or pH. Moreover, the magnetic-field strength from water showed a susceptibility frequency dependence proportional to the frequency above approximately 400 Hz. Because of the incremental effects of susceptibility, the magnetic field from water was measured using a conventional magnetic sensor (magnetic resistive; MR) in an unshielded environment. ©2006 The Japan Society of Applied Physics.

    DOI: 10.1143/JJAP.45.L1097

    Web of Science

    Scopus

    researchmap

  • Low-frequency eddy current imaging using mr sensor detecting tangential magnetic field components for nondestructive evaluation

    Keiji Tsukada, Toshihiko Kiwa, Tomoaki Kawata, Yudai Ishihara

    IEEE Transactions on Magnetics   42 ( 10 )   3315 - 3317   2006年10月

     詳細を見る

    記述言語:英語   出版者・発行元:IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC  

    An eddy-current distribution imaging system using a wide-area magnetic field exposure has been developed. This system can be employed to detect deep metal cracks using a magnetic resistive (MR) sensor. The measuring system consists of the exposure coil, MR sensors, measuring circuits, lock-in amplifier, xy stage, and a personal computer. To detect the eddy current distribution, the imaging system uses a pair of MR sensors that detect the x and y magnetic field components parallel to the metal surface. The system operates at a low-frequency range in order to obtain depth of penetration. An artificial defect consisting of a multilayer A1 substrate sample with a bottom half slit was measured to test the system. The change in the eddy current distribution image due to the presence of the flaw was obtained. In particular, it was determined that the detection of the slit depth was improved by this lower exposure frequency. © 2006, IEEE. All rights reserved.

    DOI: 10.1109/TMAG.2006.879754

    Web of Science

    Scopus

    researchmap

  • A study of fast response characteristics for hydrogen sensing with platinum FET sensor

    K. Tsukada, T. Kiwa, T. Yamaguchi, S. Migitaka, Y. Goto, K. Yokosawa

    Sensors and Actuators, B: Chemical   114 ( 1 )   158 - 163   2006年3月

     詳細を見る

    記述言語:英語   出版者・発行元:ELSEVIER SCIENCE SA  

    The fast response characteristics of a Pt-FET hydrogen sensor have been investigated using a hydrogen gas flow system and a flow-through cell for the sensor. The Pt-FET hydrogen sensor showed good linear response, detecting hydrogen concentrations from 10 ppm to 10%, and had a sensitivity of -25.1 mV/decade at room temperature, which is close to the value for the Nernstian slope. The transient response characteristic shows that the equivalent catalytic reaction on the platinum surface is dominant in the response time. © 2005 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.snb.2005.04.026

    Web of Science

    Scopus

    researchmap

  • Multipoint measurements of hydrogen gas using FET type hydrogen sensors

    T. Kiwa, T. Yamaguchi, K. Yokosawa, K. Tsukada

    Proc. the 11the Int'l Meeting on Chemical Sensors (IMCS11, 16-19 July 2006)   2006年

     詳細を見る

  • Magnetic property mapping system for analyzing three-dimensional magnetic components

    Keiji Tsukada, Toshihiko Kiwa

    Review of Scientific Instruments   77 ( 6 )   2006年

     詳細を見る

    記述言語:英語   出版者・発行元:AMER INST PHYSICS  

    A magnetic measurement system utilizing a vector magnetic sensor for analyzing and mapping low frequency magnetic properties of metals has been developed for nondestructive evaluation. The measurement system consists mainly of an induction coil which can expose a large sample area, a vector magnetic sensor for detecting magnetic fields emanating from a sample, a lock-in amplifier, and a two-dimensional scanning stage. The system was determined to have a high magnetic sensitivity corresponding to less than 1 nT in the locked-in state. The magnetic field strength change was detected in a sample that contained a slit of width greater than 1 mm. Time sequential vector component (normal and tangential) maps were developed. An iron plate as an example of a ferromagnetic metal and an aluminum plate as an example of a good conducting and nonferromagnetic material were compared using this system. Analyzing the vector component maps could differentiate differences in the magnetic properties, such as permeability, eddy current distribution, and residual magnetism. © 2006 American Institute of Physics.

    DOI: 10.1063/1.2209949

    Web of Science

    Scopus

    researchmap

  • Hydrogen reaction characteristics of FET sensors with catalytic metal gate inhigy hydrogen concentration

    K. Tsukada, T. Kiwa, T. Yamaguchi, K. Yokosawa

    Proc. the 11the Int'l Meeting on Chemical Sensors (IMCS11, 16-19 July 2006)   2006年

     詳細を見る

  • Humidity effect on the properties of FET-type hydrogen sensors

    T. Kiwa, T. Yamaguchi, S. Nakada, K. Yokosawa, K. Tsukada

    Proc. the 11the Int'l Meeting on Chemical Sensors (IMCS11, 16-19 July 2006)   2006年

     詳細を見る

  • 低周波磁場を用いた金属欠陥の2次元マッピング

    河田知明, 山田博信, 紀和利彦, 塚田啓二

    電気学会基礎・材料・共通部門大会(CD-ROM)   2006   2006年

     詳細を見る

  • 生体組織の磁気応答特性評価

    宗行健太, 増田祐生, 紀和利彦, 塚田啓二

    電気学会基礎・材料・共通部門大会(CD-ROM)   2006   2006年

     詳細を見る

  • FET型水素センサによるガス濃度分布計測

    吉武剣, 紀和利彦, 塚田啓二, 横沢宏一

    電気学会全国大会講演論文集   2006 ( 3 )   2006年

     詳細を見る

  • FET型水素センサ応答特性の湿度影響評価

    紀和利彦, 山口富治, 中田章太, 塚田啓二, 横沢宏一

    電気学会全国大会講演論文集   2006 ( 3 )   2006年

     詳細を見る

  • 低周波磁場欠陥検査手法の開発

    石原雄大, 紀和利彦, 塚田啓二

    電気学会全国大会講演論文集   2006 ( 2 )   2006年

     詳細を見る

  • Laser terahertz emission system to investigate hydrogen gas sensors

    Toshihiko Kiwa, Keiji Tsukada, Masato Suzuki, Masayoshi Tonouchi, Sonoko Migitaka, Koichi Yokosawa

    Applied Physics Letters   86 ( 26 )   1 - 3   2005年6月

     詳細を見る

    記述言語:英語   出版者・発行元:AMER INST PHYSICS  

    A laser terahertz emission system is proposed to investigate the catalytic metal/semiconductor interfaces of hydrogen sensors. Samples were fabricated by depositing a catalytic metal thin film on a semi-insulating silicon substrate. A femtosecond laser was used to radiate terahertz waves from the sample in a gas cell filled with a hydrogen and nitrogen gas mixture. The peak amplitude of the terahertz waves decreased with increasing hydrogen concentration. We also fabricated a metal-oxide-semiconductor field effect transistor hydrogen sensor, and compared its properties with the terahertz radiation properties. These results suggest that the laser terahertz emission system is a potential tool to investigate catalytic metal/semiconductor interfaces. © 2005 American Institute of Physics.

    DOI: 10.1063/1.1954885

    Web of Science

    Scopus

    researchmap

  • Imaging of large-scale integrated circuits using laser-terahertz emission microscopy. 国際誌

    Masatsugu Yamashita, Kodo Kawase, Chiko Otani, Toshihiko Kiwa, Masayoshi Tonouchi

    Optics express   13 ( 1 )   115 - 20   2005年1月

     詳細を見る

    記述言語:英語   出版者・発行元:OPTICAL SOC AMER  

    We present the redesign and improved performance of the laser terahertz emission microscope (LTEM), which is a potential tool for locating electrical failures in integrated circuits. The LTEM produces an image of the THz waves emitted when the circuit is irradiated by a femtosecond laser; the amplitude of the THz emission is proportional to the local electric field. By redesigning the optical setup and improving the spatial resolution of the system to below 3 microm, we could extend its application to examining of large-scale integration circuits. As example we show the THz emission pattern of the electric field in an 8-bit microprocessor chip under bias voltage.

    DOI: 10.1364/OPEX.13.000115

    Web of Science

    Scopus

    PubMed

    researchmap

  • Frequency detection of focused sub-THz waves using a high-T<inf>c</inf> Josephson junction

    T. Miyadera, I. Kawayama, T. Kiwa, K. Tsukada, M. Tonouchi

    Physica C: Superconductivity and its Applications   426-431 ( II )   1726 - 1730   2005年

     詳細を見る

    記述言語:英語   出版者・発行元:ELSEVIER SCIENCE BV  

    We have proposed a new type of frequency detection system of sub-terahertz electromagnetic waves using a photomixing technique and a Josephson junction detector. The photomixer illuminated by two lasers with different wavelengths generates coherent electromagnetic waves that include a frequency component corresponding to the frequency difference of the two lasers. The generated electromagnetic waves were radiated from a horn antenna and focused to the Josephson junction detector with Si lens. The high-Tc Josephson junction operates as a frequency detector for electromagnetic waves. Using this system, we observed the Shapiro steps of 188 μV that correspond to the frequencies of 90.8 GHz. © 2005 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.physc.2005.02.136

    Web of Science

    Scopus

    researchmap

  • Noninvasive measurements of magnetic field generated by induced current within human body under exposure to very low frequency electromagnetic fields

    Keiji Tsukada, Toshihiko Kiwa

    Japanese Journal of Applied Physics, Part 2: Letters   44 ( 16-19 )   L532 - L534   2005年

     詳細を見る

    記述言語:英語   出版者・発行元:INST PURE APPLIED PHYSICS  

    We have developed a measurement system for a magnetic field that is generated by the induced ionic current within the human body under exposure to very low frequency electromagnetic fields, and compared the magnetic field strength obtained with those of a magnetomyogram (MMG). The developed system consists of an exposure coil, a magnetic sensor, a lock-in detector, and data acquisition. The waveform characteristics of the magnetic field of the induced current (MFIC) of the abdomen from 1 kHz to 400 Hz are obtained. Compared with the magnetic field strength of abdominal MMG, abdominal MFIC is stronger at an exposure electromagnetic field greater than the μ,T order. © 2005 The Japan Society of Applied Physics.

    DOI: 10.1143/JJAP.44.L532

    Web of Science

    Scopus

    researchmap

  • Spatial analysis of the three dimensional components of a magnetocardiogram

    K. Tsukada, T. Kiwa, K. Ogata, T. Miyashita, A. Kandori

    INTERMAG ASIA 2005: Digests of the IEEE International Magnetics Conference   620   2005年

  • Terahertz emission properties from palladium/silicon interface

    Toshihiko Kiwa, Keiji Tsukada, Masato Suzuki, Masayoshi Tonouchi, Sonoko Migitaka, Koichi Yokosawa

    Digest of Technical Papers - International Conference on Solid State Sensors and Actuators and Microsystems, TRANSDUCERS '05   1   263 - 266   2005年

     詳細を見る

    記述言語:英語   出版者・発行元:IEEE  

    Laser terahertz (THz) emission and detection system for investigating catalytic metal/semiconductor interface of the hydrogen sensors was proposed and developed. THz radiation from palladium/silicon structures was successfully obtained. The properties of THz radiation under hydrogen and nitrogen gas mixture were investigated. The peak amplitude of THz radiation was decreased by increasing the volume concentration of hydrogen gas. This change in the amplitude can be explained by change in the local field near the surface of silicon. This result indicates that the system is one of potential tool for non-destructive and non-contact measurement of the hydrogen sensors. © 2005 IEEE.

    DOI: 10.1109/SENSOR.2005.1496407

    Web of Science

    Scopus

    researchmap

  • 水素ガスセンサの感応膜の特性評価

    山口富治, 紀和利彦, 塚田啓二, 中野定樹, 右高園子, 横沢宏一

    電気学会全国大会講演論文集   2005 ( 3 )   2005年

     詳細を見る

  • 導波路結合型サブテラヘルツ電磁波発生・検出システムの開発

    金城隆平, 宮寺達也, 川山巌, 村上博成, 紀和利彦, 塚田啓二, 斗内政吉

    応用物理学関係連合講演会講演予稿集   52nd ( 1 )   2005年

     詳細を見る

  • テラヘルツ波を用いた水素センサー評価システムの構築

    紀和利彦, 塚田啓二, 鈴木正人, 斗内政吉, 右高園子, 横沢宏一

    応用物理学関係連合講演会講演予稿集   52nd ( 3 )   2005年

     詳細を見る

  • 空間結合型サブテラヘルツ電磁波発生・検出システムの開発

    川山厳, 宮寺達也, 村上博成, 紀和利彦, 塚田啓二, 斗内政吉

    応用物理学関係連合講演会講演予稿集   52nd ( 1 )   2005年

     詳細を見る

  • テラヘルツ電磁波による水素センサー特性評価

    紀和利彦, 塚田啓二, 鈴木正人, 斗内政吉, 右高園子, 横沢宏一

    電気学会全国大会講演論文集   2005 ( 3 )   2005年

     詳細を見る

  • 磁気センサーを用いた金属検出器の開発

    河田知明, 紀和利彦, 塚田啓二

    電気学会全国大会講演論文集   2005 ( 2 )   2005年

     詳細を見る

  • 生体内誘導電流の磁気的計測方法

    塚田啓二, 紀和利彦

    日本ME学会大会論文集   44th   2005年

     詳細を見る

  • 磁気センサを用いた生体内誘導電流の計測

    塚田啓二, 紀和利彦

    電気学会全国大会講演論文集   2005 ( 2 )   2005年

     詳細を見る

  • 低周波磁場照射による生体内の誘導電流の磁気的計測

    塚田啓二, 紀和利彦

    応用物理学関係連合講演会講演予稿集   52nd ( 1 )   2005年

     詳細を見る

  • THz time domain spectroscopy of pulsed laser deposited BaTiO <inf>3</inf> thin films

    M. Misra, K. Kotani, T. Kiwa, I. Kawayama, H. Murakami, M. Tonouchi

    Applied Surface Science   237 ( 1-4 )   421 - 426   2004年10月

     詳細を見る

    記述言語:英語   出版者・発行元:ELSEVIER SCIENCE BV  

    We have measured the dielectric properties of pulsed laser deposited 1.1μm thick BaTiO 3 (BTO) thin films on MgO substrate in the MHz and THz frequency region. The properties of two BTO thin films deposited at substrate temperature 790 and 840°C have been studied. X-ray diffraction pattern and AFM measurement of the films shows that the BTO film grown at temperature 840°C has better epitaxial growth and smooth surface compared to the film grown at 790°C. The dielectric properties of thin films have been measured by THz time domain spectroscopy (THz-TDS) in the frequency range from 0.3 to 2.5THz and by interdigital electrode measurement in the region from 10kHz to 10MHz. The BTO thin film deposited at higher temperature has a higher dielectric constant and tunability in the MHz frequency range whereas at THz frequencies the real and imaginary part of the refractive index and dielectric constant of both films show almost similar behavior. © 2004 Elsevier B.V. All rights reserved.

    DOI: 10.1016/S0169-4332(04)01012-8

    Web of Science

    Scopus

    researchmap

  • Ultrafast optical study of amorphous Ge thin films for superconductor/ semiconductor hybrid devices

    T. Miyadera, T. Kiwa, I. Kawayama, H. Murakami, M. Tonouchi

    Physica C: Superconductivity and its Applications   412-414 ( SPEC. ISS. )   1602 - 1606   2004年10月

     詳細を見る

    記述言語:英語   出版者・発行元:ELSEVIER SCIENCE BV  

    We investigated the optical response of amorphous (a-) Ge thin films by a time-resolved reflectivity measurement and the observation of terahertz radiation from a-Ge photoconductive switch coupled with Au/Cr transmission lines. The results show that the lifetime of photocarrier in the a-Ge is about 0.9 ps, and the pulse width of terahertz beam radiated from the photoconductive switch is about 1 ps. These results indicate that a-Ge can be used as an optical-to-electrical converter in sub-terahertz frequency range. However, the peak width of a-Ge photoconductive switches with YBCO transmission lines is about 2 ps and broad compared with the result with Au/Cr transmission lines. © 2004 Published by Elsevier B.V.

    DOI: 10.1016/j.physc.2003.12.089

    Web of Science

    Scopus

    researchmap

  • Real-time monitoring of a photomixing signal using a high-T<inf>C</inf> Josephson junction

    Toshihiko Kiwa, Masayoshi Tonouchi

    Superconductor Science and Technology   17 ( 8 )   998 - 1002   2004年8月

     詳細を見る

    記述言語:英語   出版者・発行元:IOP PUBLISHING LTD  

    An optical-microwave conversion system has been proposed as a high-stability oscillator in the microwave and millimetre-wave frequency region. A photomixer with heterodyne mixing of two lasers was applied to generate electromagnetic waves and a high-TC grain boundary Josephson junction detector was used to monitor the frequency of the electromagnetic waves in real time. We described the system in detail; it employed a sealed optical connector to introduce the optical signal directly into the cryostat.

    DOI: 10.1088/0953-2048/17/8/008

    Web of Science

    Scopus

    researchmap

  • Terahertz radiation from InAs/Al<inf>x</inf>Ga<inf>1-x</inf>Sb (x = 0.5) heterostructures

    Masato Suzuki, Toshihiko Kiwa, Masayoshi Tonouchi, Yoji Nakajima, Shigehiko Sasa, Masataka Inoue

    Physica E: Low-Dimensional Systems and Nanostructures   22 ( 1-3 )   574 - 577   2004年4月

     詳細を見る

    記述言語:英語   出版者・発行元:ELSEVIER SCIENCE BV  

    We observed terahertz radiation from InAs/Al0.5Ga 0.5Sb heterostructures excited by femtosecond pulses of mode-locked Ti:sapphire laser in the temperature range of 20-300 K. The radiation pseudo-reflected is monitored in time domain by a low temperature grown GaAs photoswitch. Although the waveforms are almost identical irrespective of temperatures, their maximum amplitude is strongly temperature dependent and peaks at around 100 K. Laser power dependence of the amplitude indicates that the excitation at power densities above 57 W/cm2 induce saturation presumably due to screening effect. © 2003 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.physe.2003.12.073

    Web of Science

    Scopus

    researchmap

  • An imaging and quantitative analysis technique for diagnosis of electro-pysiological excitation abnormality of heart

    K. Tsukada, K. Ogata, T. Miyashita, S. Yamada, H. Horigome, J. Shiono, T. Kiwa, A. Kandori, I. Yamaguchi

    Proceedings of the 14th International Conference on Biomagnetism   2004年

     詳細を見る

  • A DEVELOPMENT OF MEASURING SYSTEM OF INDUCED CURRENT IN HUMAN BODY DUE TO LOW FREQUENCY ELECTROMAGNETIC IRRADIATION

    Keiji Tsukada, Toshihiko Kiwa

    Proceedings of Biological Effects of EMFs, 3rd International Workshop   2004年

     詳細を見る

  • 心臓磁場の空間解析

    楠野順也, 紀和利彦, 塚田啓二, 緒方邦臣, 宮下豪, 神鳥明彦

    日本ME学会秋季大会論文集   18th   2004年

     詳細を見る

  • LSI故障解析用レーザーテラヘルツエミッション顕微鏡の開発 レーザーテラヘルツエミッション顕微鏡による集積回路観察

    山下将嗣, 紀和利彦, 斗内政吉, 二川清, 大谷知行, 川瀬晃道

    マイクロファブリケーション研究の最新動向   15   2004年

     詳細を見る

  • ジョセフソン接合を用いたフォトミキシング電磁波周波数検出・安定化システム

    紀和利彦, 斗内政吉

    応用物理学関係連合講演会講演予稿集   51st ( 3 )   2004年

     詳細を見る

  • 運動負荷による心臓磁場変化の解析

    塩田隆雄, 紀和利彦, 塚田啓二, 緒方邦臣, 宮下豪, 神鳥明彦

    日本ME学会秋季大会論文集   18th   2004年

     詳細を見る

  • 光ファイバ結合型コンパクトテラヘルツ分光ヘッドの開発

    大野恭裕, 紀和利彦, 斗内政吉

    応用物理学関係連合講演会講演予稿集   51st ( 3 )   2004年

     詳細を見る

  • 光ファイバ結合型コンパクトテラヘルツ分光システムの構築

    大野恭裕, 井上亮太郎, 紀和利彦, 塚田啓二, 斗内政吉

    応用物理学会学術講演会講演予稿集   65th ( 3 )   2004年

     詳細を見る

  • テラヘルツエミッション顕微鏡によるMOSトランジスタの非接触測定

    山下将嗣, 紀和利彦, 斗内政吉, 二川清, 川瀬晃進

    応用物理学関係連合講演会講演予稿集   51st ( 3 )   2004年

     詳細を見る

  • レーザーテラヘルツエミッション顕微鏡による集積回路観察

    山下将嗣, 紀和利彦, 斗内政吉, 大谷知行, 川瀬晃道

    レーザ顕微鏡研究会講演会抄録集   30th   2004年

     詳細を見る

  • チューナブルサブテラヘルツ電磁波発生・検出システム

    宮寺達也, 川山巌, 紀和利彦, 塚田啓二, 斗内政吉

    応用物理学会学術講演会講演予稿集   65th ( 1 )   2004年

     詳細を見る

  • レーザーテラヘルツ放射顕微鏡

    斗内政吉, 紀和利彦, 山下将嗣, 川瀬晃道

    応用物理学関係連合講演会講演予稿集   51st ( 0 )   2004年

     詳細を見る

  • 高温超伝導体におけるポンプ・プローブテラヘルツ電磁波励起観測

    寺坂宏介, 富成征弘, 高橋宏平, 紀和利彦, 村上博成, 斗内政吉

    応用物理学関係連合講演会講演予稿集   51st ( 1 )   2004年

     詳細を見る

  • 心磁の3次元ベクトル成分解析

    増田祐生, 紀和利彦, 塚田啓二, 緒方邦臣, 宮下豪, 神鳥明彦

    日本ME学会秋季大会論文集   18th   2004年

     詳細を見る

  • Optical response of amorphous Ge photoconductive switches with YBCO transmission lines

    I. Kawayama, T. Miyadera, Y. Doda, T. Kiwa, H. Murakami, M. Tonouchi

    Superconductor Science and Technology   16 ( 12 )   1475 - 1478   2003年12月

     詳細を見る

    記述言語:英語   出版者・発行元:IOP PUBLISHING LTD  

    Amorphous germanium (a-Ge) photoconductive switches coupled with YBCO transmission lines are fabricated on MgO (100) substrates. The optical responses of the photoconductive switches at lower temperatures are examined using the terahertz beam generation technique. The results have revealed that the a-Ge photoconductive switch can stably work at low temperatures and operation frequencies around 100 GHz. We also discuss the effects of YBCO transmission lines and the deterioration of the interface between a-Ge and YBCO.

    DOI: 10.1088/0953-2048/16/12/034

    Web of Science

    Scopus

    researchmap

  • Generation of sub-terahertz waves using a semiconductor photomixer

    Toshihiko Kiwa, Hironaru Murakami, Masayoshi Tonouchi

    Superconductor Science and Technology   16 ( 12 )   1540 - 1543   2003年12月

     詳細を見る

    記述言語:英語   出版者・発行元:IOP PUBLISHING LTD  

    A low-temperature-grown GaAs (LT-GaAs) photoconductive switch has been utilized as a photomixer in the sub-terahertz (sub-THz) region. The usefulness of the switch has been demonstrated by detecting the radiated sub-THz wave with a high-TC Josephson junction detector consisting a series of nine junctions and a gold-coated log-periodic antenna. The sub-THz waves are radiated from the photoconductive switch by introducing the optical heterodyne signal of two semiconductor lasers. Although the radiation power of the photoconductive switch is three orders of magnitude lower than a conventional photodiode, the sub-THz waves from the switch were successfully observed in the difference voltage response of the junctions. This result suggests that the LT-GaAs switch can be used as the photomixer in the optical-microwave converter for superconductive electronics. We have also studied the properties of a radiated sub-THz frequency spectrum using a Martin-Puplett interferometer.

    DOI: 10.1088/0953-2048/16/12/048

    Web of Science

    Scopus

    researchmap

  • Laser terahertz-emission microscope for inspecting electrical faults in integrated circuits. 国際誌

    Toshihiko Kiwa, Masayoshi Tonouchi, Masatsugu Yamashita, Kodo Kawase

    Optics letters   28 ( 21 )   2058 - 60   2003年11月

     詳細を見る

    記述言語:英語   出版者・発行元:OPTICAL SOC AMER  

    A laser terahertz-emission microscope (LTEM) system is proposed and developed for inspecting electrical faults in integrated circuits (IC). We test a commercial operational amplifier while the system is operating. Two-dimensional terahertz-emission images of the IC chip are clearly observed while the chip is scanned with a femtosecond laser. When one of the interconnection lines is cut, the damaged chip has a LTEM image different from that of normal chips. The results indicate that the LTEM system is a potential tool for IC inspection.

    DOI: 10.1364/OL.28.002058

    Web of Science

    Scopus

    PubMed

    researchmap

  • Characteristics of superconducting flux flow transistors under irradiation of femtosecond laser pulses

    Y. Doda, T. Kiwa, I. Kawayama, H. Murakami, M. Tonouchi

    Physica C: Superconductivity and its Applications   392-396 ( PART 2 )   1504 - 1508   2003年10月

     詳細を見る

    記述言語:英語   出版者・発行元:ELSEVIER SCIENCE BV  

    We have fabricated superconducting flux flow transistors with YBCO thin films and investigated the vortex flow characteristics under the irradiation of femtosecond laser pulses. The vortex flow velocity was calculated by the magnetic field dependence of the flow voltage. The obtained velocity without laser irradiation is 0.08-1.37 × 104 m/s for the bias current IB = 0.4-0.8 mA. The flow voltage increased gradually when the irradiated laser power was up to 10 mW, however, it increased drastically when the laser power was more than 10 mW. The maximum velocity of 6.3 × 10 4 m/s was obtained at the laser power of 15 mW. The result indicates that the laser pulses excite the vortices and accelerate the vortex velocity. © 2003 Elsevier B.V. All rights reserved.

    DOI: 10.1016/S0921-4534(03)00779-2

    Web of Science

    Scopus

    researchmap

  • THz radiation properties of Tl<inf>2</inf>Ba<inf>2</inf>CaCu<inf>2</inf>O<inf>8+δ</inf> thin films excited by femtosecond laser pulses

    Yukihiro Tominari, Toshihiko Kiwa, Hironaru Murakami, Masayoshi Tonouchi, Henrik Schneidewind, Hagen Wald, Paul Seidel

    IEEE Transactions on Applied Superconductivity   13 ( 2 III )   3730 - 3732   2003年6月

     詳細を見る

    記述言語:英語   出版者・発行元:IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC  

    Previously, we found the resonant THz wave radiation from c-axis oriented underdoped Tl2Ba2CaCu2O8+δ (Tl-2212) thin films by femtosecond laser pulse illumination under magnetic field. The properties of the resonant THz wave were well explained by the Josephson plasma resonance phenomenon. In the present study, the THz radiation properties were investigated for an overdoped Tl-2212 thin films. The amplitudes of THz waveform radiated under a bias current condition is much smaller than those of previous sample, while any trace of resonant THz signals could not be observed under magnetic field. These experimental results indicate the possibility that the initial THz wave radiated by ultrafast modulation in eddy-current around the vortices has an important role to excite the collective mode oscillation.

    DOI: 10.1109/TASC.2003.812529

    Web of Science

    Scopus

    researchmap

  • Backscattered terahertz radiation imaging system to visualize supercurrent distributions

    T. Kiwa, Y. Kamata, M. Misra, H. Murakami, M. Tonouchi

    IEEE Transactions on Applied Superconductivity   13 ( 2 III )   3675 - 3678   2003年6月

     詳細を見る

    記述言語:英語   出版者・発行元:IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC  

    A new type of terahertz (THz) radiation imaging has been proposed and demonstrated. The supercurrent distributions were visualized by detecting the backscattered THz radiation from optically excited high-temperature superconductors. The supercurrent distributions were clearly observed in 100- and 500-nmthick YBa2Cu3O7-δ films in the remanent state. Our system has performance similar to the system with transmission configuration.

    DOI: 10.1109/TASC.2003.812428

    Web of Science

    Scopus

    researchmap

  • Coherent terahertz radiation from Tl<inf>2</inf>Ba<inf>2</inf>CaCu<inf>2</inf>O<inf>8+δ</inf> thin films excited by optical laser pulse under magnetic field

    Yukihiro Tominari, Toshihiko Kiwa, Hironaru Murakami, Masayoshi Tonouchi, Hagen Wald, Paul Seidel, Henrik Schneidewind

    Physica C: Superconductivity and its Applications   388-389   481 - 482   2003年5月

     詳細を見る

    記述言語:英語   出版者・発行元:ELSEVIER SCIENCE BV  

    We observed terahertz (THz) pulse radiation from Tl2Ba2CaCu2O8+δ thin films by femtosecond optical pulse excitation under a bias-current condition and a radial magnetic field of ∼100 Oe nearly parallel to the c-axis of the film. The observed waveform under magnetic field showed clear oscillations below 80 K, and the Fourier spectrum showed an additional peak other than the frequency components observed in the bias-current condition. The additional peak (630 GHz at 24 K) shifted towards lower frequency region with increasing temperature. The observed resonant THz wave behavior is quantitatively explained by Josephson plasma phenomenon. © 2003 Elsevier Science B.V. All rights reserved.

    DOI: 10.1016/S0921-4534(02)02589-3

    Web of Science

    Scopus

    researchmap

  • THz imaging of supercurrent distribution in Meissner state of LPE-BSCCO film

    H. Murakami, T. Kiwa, M. Tonouchi, T. Yasuda

    Physica C: Superconductivity and its Applications   388-389   479 - 480   2003年5月

     詳細を見る

    記述言語:英語   出版者・発行元:ELSEVIER SCIENCE BV  

    The terahertz (THz) imaging system applicable to bulk or thick superconductors was developed. The supercurrent distribution in Bi2Sr2CaCu2O8+δ (BSCCO) thick film in Meissner state was observed. The experimental technique and the results obtained on a liquid phase epitaxy grown (LPE-)BSCCO thick film were presented. The resistive measurement showed the critical temperature of about 75 K.

    DOI: 10.1016/S0921-4534(02)02588-1

    Web of Science

    Scopus

    researchmap

  • 高温超伝導体ジョセフソン接合を用いたフォトミキシング光-マイクロ波変換システム

    紀和利彦, 斗内政吉

    低温工学   38 ( 1 )   2003年

  • 後方散乱型テラヘルツ電磁波イメージングによる半導体IC断線評価

    紀和利彦, 斗内政吉

    応用物理学関係連合講演会講演予稿集   50th ( 3 )   2003年

     詳細を見る

  • フォトミキシング光-マイクロ波変換システム (II)

    紀和利彦, 村上博成, 斗内政吉

    応用物理学会学術講演会講演予稿集   64th ( 1 )   2003年

     詳細を見る

  • フォトミキシング電磁波のジョセフソン接合直列アレイによる検出

    紀和利彦, 村上博成, 斗内政吉

    応用物理学関係連合講演会講演予稿集   50th ( 1 )   2003年

     詳細を見る

  • 非晶質Ge薄膜の高速光応答計測

    宮寺達也, 紀和利彦, 川山巌, 斗内政吉

    光物性研究会論文集   14th   2003年

     詳細を見る

  • 超伝導/半導体ハイブリッド光インターフェース応用に向けた非晶質Ge薄膜の高速光応答計測

    宮寺達也, 紀和利彦, 川山巌, 村上博成, 斗内政吉

    電子情報通信学会技術研究報告   103 ( 367(SCE2003 19-27) )   2003年

     詳細を見る

  • フォトミキサー・High-T<sub>C</sub>ジョセフソン接合ハイブリッドシステムの開発

    紀和利彦, 鈴木正人, 村上博成, 斗内政吉

    電子情報通信学会技術研究報告   103 ( 367(SCE2003 19-27) )   2003年

     詳細を見る

  • IC断線評価システムの空間分解能評価

    山下将嗣, 紀和利彦, 川瀬晃道, 斗内政吉

    応用物理学会学術講演会講演予稿集   64th ( 3 )   2003年

     詳細を見る

  • YBa<sub>2</sub>Cu<sub>3</sub>O<sub>7-x</sub>薄膜を伝送線に持つ非晶質Ge光スイッチの低温特性

    宮寺達也, 紀和利彦, 川山巌, 村上博成, 斗内政吉

    応用物理学関係連合講演会講演予稿集   50th ( 1 )   2003年

     詳細を見る

  • Relaxation dynamics of optically excited quasi-particles in BSCCO

    H. Murakami, T. Yasuda, Y. Tominari, T. Kiwa, M. Tonouchi, T. Uchiyama, I. Iguchi, Z. Wang

    Physica C: Superconductivity and its Applications   378-381 ( PART 1 )   320 - 323   2002年10月

     詳細を見る

    記述言語:英語   出版者・発行元:ELSEVIER SCIENCE BV  

    To investigate the multi-excitation processes on the low-lying electronic structure of high-TC superconductors, time-domain pump and probe measurement has been carried out on under- and over-doped Bi2Sr2CaCu2O8+δ films. In the underdoped film, we found evidence for coexistence of two excitation states due to superconducting gap Δs and pseudogap Δp below TC. The observed relaxation processes of optically excited quasi-particles were well explained by two relaxation times of T-dependent τs and almost T-independent τp (0.7 ± 0.3 ps below 150 K). The τp existed up to T* ∼ 200 K and disappeared above 225 K. On the other hand, only one relaxation time, τs, was observed in the overdoped film at T = 10 K. The relaxation time, τs=4.2 ± 0.3 ps (below 40 K), for the underdoped sample was shorter than τs = 5.9 ± 0.2 ps (at T = 10 K) for the overdoped one, and about two times longer than τs = 2.1 ± 0.1 ps for YBa2Cu3O7-δ thin film. © 2002 Elsevier Science B.V. All rights reserved.

    DOI: 10.1016/S0921-4534(02)01435-1

    Web of Science

    Scopus

    researchmap

  • Partial and macroscopic phase coherences in an underdoped Bi<inf>2</inf>Sr<inf>2</inf>CaCu<inf>2</inf>O<inf>8+δ</inf> thin film

    H. Murakami, T. Kiwa, N. Kida, M. Tonouchi, T. Uchiyama, I. Iguchi, Z. Wang

    Europhysics Letters   60 ( 2 )   288 - 294   2002年10月