研究者詳細 - 紀和　利彦

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

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

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

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

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

Magnetic property mapping system for analyzing three-dimensional magnetic components

Keiji Tsukada, Toshihiko Kiwa

Review of Scientific Instruments 77 ( 6 ) 2006年

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

最近の技術から集積回路評価用レーザーテラヘルツ放射顕微鏡の開発 ("開拓"進むテラヘルツ領域)

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

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

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

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

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

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

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

山下将嗣, 紀和利彦, 斗内政吉

光学 34 ( 9 ) 472 - 474 2005年9月

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

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

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

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

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

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

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

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