Faculty Profiles - UEDA Hiroshi

Papers - UEDA Hiroshi

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Evaluation of Magnetic Field Homogeneity of a Conduction-Cooled REBCO Magnet With a Room-Temperature Bore of 200 mm Reviewed

H. Miyazaki, S. Iwai, Y. Otani, M. Takahashi, T. Tosaka, K. Tasaki, S. Nomura, T. Kurusu, H. Ueda, S. Noguchi, A. Ishiyama, S. Urayama, H. Fukuyama

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY 26 ( 3 ) 7414412 2016.4

Language：English Publishing type：Research paper (scientific journal) Publisher：IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC

Development of a high-temperature superconducting magnet wound with REBa2Cu3O7-delta (REBCO)-coated conductor for ultrahigh-field magnetic resonance imaging (MRI) is in progress. Our final targets are 9.4-T MRI systems for whole-body and brain imaging. Since REBCO-coated conductors feature high mechanical strength under a tensile stress and high critical current density, superconducting magnets could be made smaller by using REBCO coils. Superconducting magnets for MRI require homogeneous stable magnetic fields. The homogeneity of the magnetic field is highly dependent on the size and current density of the coils. Furthermore, in REBCO magnets, the screening-currentinduced magnetic field that changes the magnetic field distribution of the magnet is one of the critical issues. In order to evaluate the magnetic field homogeneity and the screening-current-induced magnetic field of REBCO magnets, a conduction-cooled REBCO magnet with a room-temperature bore of 200 mm was fabricated and tested. The REBCO coils were composed of 12 single pancakes, and the size of the homogeneous magnetic field region was 100-mm diameter spherical volume (DSV). The central magnetic field was as high as 1 T at 285 A. The magnetic field distribution on the z-axis was measured by using an NMR probe. The maximum error magnetic field was 470 parts per million (ppm) in the range from -50 to +50 mm, as well as in the coefficients of the spherical harmonic expansion for a 100-mm DSV. The error magnetic fields due to the screening-current-induced magnetic field were less than 5 ppm, because there was a sufficient distance between the coil and the homogeneous magnetic field region. The main reason for the error magnetic field was dimensional errors in the outer diameters and positions on the z-axis.

DOI： 10.1109/TASC.2016.2529841

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R&D Progress of HTS Magnet Project for Ultrahigh-field MRI Reviewed

Taizo Tosaka, Hiroshi Miyazaki, Sadanori Iwai, Yasumi Otani, Masahiko Takahashi, Kenji Tasaki, Shunji Nomura, Tsutomu Kurusu, Hiroshi Ueda, So Noguchi, Atsushi Ishiyama, Shinichi Urayama, Hidenao Fukuyama

PROCEEDINGS OF THE 28TH INTERNATIONAL SYMPOSIUM ON SUPERCONDUCTIVITY (ISS 2015) 81 145 - 148 2016.3

Language：English Publishing type：Research paper (international conference proceedings) Publisher：ELSEVIER SCIENCE BV

An R&D project on high-temperature superconducting (HTS) magnets using rare-earth Ba2Cu3O7 (REBCO) wires was started in 2013. The project objective is to investigate the feasibility of adapting REBCO magnets to ultrahigh field (UHF) magnetic resonance imaging (MRI) systems. REBCO wires are promising components for UHF-MRI magnets because of their superior superconducting and mechanical properties, which make them smaller and lighter than conventional ones. Moreover, REBCO magnets can be cooled by the conduction-cooling method, making liquid helium unnecessary. In the past two years, some test coils and model magnets have been fabricated and tested. This year is the final year of the project. The goals of the project are: (1) to generate a 9.4 T magnetic field with a small test coil, (2) to generate a homogeneous magnetic field in a 200 mm diameter spherical volume with a 1.5 T model magnet, and (3) to perform imaging with the 1.5 T model magnet. In this paper, the progress of this R&D is described. The knowledge gained through these R&D results will be reflected in the design of 9.4 T MRI magnets for brain and whole body imaging. (C) 2016 Published by Elsevier B.V.

DOI： 10.1016/j.phpro.2016.04.034

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19pAF-4 Measurement of spin polarization of the muon beam at the RCNP-MuSIC beamline

Tomono D., Ieiri M., Ishii K., Ueda H., Kawashima Y., Kuno Y., Kohno Y., Saito T., Sakamoto H., Sato A., Shimomura K., Takahisa K., Taniguchi A., Nakazawa Y., Ninomiya K., Matsumoto Y., Hatanaka K., Baba K., Higemoto W., Fukuda M., Matsuzaki T., Miyake Y., Minagawa M., Mori Y., Morinobu S., Lai Jun

Meeting Abstracts of the Physical Society of Japan 71 2664 - 2664 2016

Development of HTS magnets for accelerators

K. Hatanaka, M. Fukuda, S. Hara, K. Kamakura, K. Shimada, Y. Yasuda, T. Yorita, H. Ueda

CYC 2016 - Proceedings of the 21st International Conference on Cyclotrons and their Applications 294 - 296 2016

Language：English Publishing type：Research paper (international conference proceedings) Publisher：Joint Accelerator Conferences Website (JACoW)

At RCNP, we have been developing magnets utilizing first generation HTS wires for this decade. HTS materials have advantages over LTS materials. Magnets can be operated at 20 K or higher temperature and cooled by cryo-coolers. The cooling structure becomes simpler and the cooling power of a cooler is higher. Owing to a large margin in operating temperature, it is possible to excite HTS magnets by AC or pulsed currents without quenching. After successful tests of proto type models, two magnets have been fabricated for practical use. Their design and operational performance of two models and the switching dipole magnet are discussed.

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Project Overview of HTS Magnet for Ultra-high-field MRI System Reviewed

Proceedings of the 27th International Symposium on Superconductivity (ISS 2014) 65 217 - 220 2015.6

Language：English Publishing type：Research paper (international conference proceedings) Publisher：ELSEVIER SCIENCE BV

A project to develop an ultra-high-field magnetic resonance imaging (MRI) system based on HTS magnets using (RE)Ba2Cu3O7 (REBCO; RE=rear earth) coils is underway. The project is supported by the Japanese Ministry of Economy, Trade and Industry and aims to establish magnet technologies for a whole-body 9.4 T MRI system. REBCO wires have high critical current density in high magnetic fields and high strength against hoop stresses, and therefore, MRI magnets using REBCO coils are expected to have cryogenic systems that are smaller, lighter, and simpler than the conventional ones. A major problem in using REBCO coils for MRI magnets is the huge irregular magnetic field generated by the screening current in REBCO tapes. Thus, the main purpose of this project is to make the influence of this screening current predictable and controllable. Fundamental technologies, including treatment of the screening currents, were studied via experiments and numerical simulations using small coils. Two types of model magnets are planned to be manufactured, and the knowledge gained in the development of the model magnets will be reflected in the magnet design of a whole-body 9.4 T MRI system. (C) 2015 Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

DOI： 10.1016/j.phpro.2015.05.122

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Development of Non-Circular REBCO Pancake Coil for High-Temperature Superconducting Cyclotron Reviewed

Xudong Wang, Hirotaka Umeda, Atsushi Ishiyama, Masaki Tashiro, Hiroshi Yamakawa, Hiroshi Ueda, Tomonori Watanabe, Shigeo Nagaya

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY 25 ( 3 ) 4601904 2015.6

Language：English Publishing type：Research paper (scientific journal) Publisher：IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC

A series of feasibility studies are carried out on the applications of a high-temperature superconducting (HTS) magnet system to a heavy-ion accelerator for particle cancer therapy. A novel HTS cyclotron is expected to be more compact and have higher efficiency than a conventional heavy ion synchrotron accelerator. A high current density is required for the HTS magnet to realize a compact HTS cyclotron. Further, a high-strength reinforcing structure is absolutely essential for the HTS magnet owing to the large Lorentz force caused by the high current density to prevent the magnet deformation and maintain the required high accuracy field. In a previous study, a novel coil structure called the Y-based oxide superconductor and reinforcing outer integrated "YOROI coil" was proposed and tested at 4.2 K in 8-T backup fields. The YOROI model coil exhibited no degradation after the excitation test with a maximum hoop stress of 1.7 GPa determined by the product of the magnetic field, current density, and coil radius. The mechanism of stress sharing between the coil winding and the reinforcing structures of the YOROI coil was numerically determined. In addition, the electromagnetic and mechanical properties of a reinforcing structure based on the YOROI coil for circular REBCO coils assuming part of the HTS cyclotron magnet system was also numerically simulated in the previous paper. In this study, a new reinforcing structure is proposed on the basis of the YOROI coil for a non-circular REBCO coil assuming part of the HTS cyclotron magnet system. The electromagnetic andmechanical properties for the new reinforcing structure are numerically determined. As a result, the proposed reinforcing structure has great ability to reduce the stress and strain acting on the coil winding to maintain the coil shape and prevent degradation in the REBCO wire.

DOI： 10.1109/TASC.2014.2365626

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Developments of hts magnets

K. Hatanaka, M. Fukuda, K. Kamakura, H. Ueda, T. Yorita, T. Saito, Y. Yasuda

2905 - 2907 2015.6

Reduction of Irregular Magnetic Field Generated by Screening Current in REBCO Coil Reviewed International journal

Hiroshi Ueda, Jun Saito, Yuta Ariya, Ayumu Mochida, Tao Wang, Xudong Wang, Koh Agatsuma, Atsushi Ishiyama

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY 25 ( 3 ) 6603205 2015.6

Authorship：Lead author,　Corresponding author Language：English Publishing type：Research paper (scientific journal) Publisher：IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC

In REBCO coils, the screening current flows in the tape in response to the normal component of the linkage flux to the tape's wide face. Generally, the radial component of the magnetic field is large at both ends of the coil winding. Therefore, changes in the winding arrangement may be expected to reduce screening current induction. Furthermore, multifilamentary or narrow REBCO tapes with widths of a few millimeters can be also expected to reduce the magnitude of the screening current. Based on the above considerations, in this paper, we numerically investigated the reduction effect on a magnetic field generated by a screening current in a REBCO coil, due to thinning tape width and varying coil winding arrangements. It was found that the screening field is inversely proportional to the number of tape filaments, whereas a smaller coil winding aspect ratio leads to a decrease in the screening field.

DOI： 10.1109/TASC.2014.2375953

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Evaluation of Magnetic-Field Distribution by Screening Current in Multiple REBCO Coils Reviewed International journal

Hiroshi Ueda, Atsushi Ishiyama, Yuta Ariya, Tao Wang, Xudong Wang, Koh Agatsuma, Hiroshi Miyazaki, Taizo Tosaka, Shunji Nomura, Tsutomu Kurusu, Shinichi Urayama, Hidenao Fukuyama

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY 25 ( 3 ) 4700705 2015.6

Authorship：Lead author,　Corresponding author Language：English Publishing type：Research paper (scientific journal) Publisher：IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC

In a superconducting coil using a REBCO tape, a large screening current is induced by the magnetic field perpendicular to the tape. The irregular magnetic field generated by this screening current affects the magnetic-field distribution in high-field magnet applications, which require a magnetic field with high accuracy and temporal stability. Therefore, in these applications of the REBCO coil, we have to investigate and suppress the influence of the screening current in the REBCO tapes. In this study, we carried out experiments and numerical simulations focusing on the irregular magnetic field generated by the screening currents in multiple-REBCO-coil models assuming real operations in magnetic applications such as NMR/MRI system. The results of the numerical simulation are in good agreement with the behaviors of the screening field observed in the experimental results. In addition, we discussed the differences in the screening field for various excitation conditions using the numerical results of the current distribution in the coil.

DOI： 10.1109/TASC.2014.2371133

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Medical Protein Separation System Using High Gradient Magnetic Separation by Superconducting Magnet

Y. Kamioka, K. Agatsuma, K. Kajikawa, H. Ueda, M. Furuse, S. Fuchino, T. Iitsuka, S. Nakamura

ADVANCES IN CRYOGENIC ENGINEERING 1573 1129 - 1134 2015.2

Language：English Publishing type：Research paper (international conference proceedings) Publisher：AMER INST PHYSICS

A high gradient magnetic separation system for medical protein using affinity magnetic nano-beads has been developed. Medical protein such as monoclonal antibody or immunoglobulin is an important substance as a medicine for cancer etc. However; the separation system of these medical protein has very low separation rate and the cost of product is extremely high. The developed system shows very high separation efficiency and can achieve low cost by large production rate compared to the system now using in this field. The system consists of a 3T superconducting magnet cooled by a cryo-cooler, a filter made of fine magnetic metal wires of about 30 mu m diameter and a demagnetization circuit and a liquid circulation pump for solvent containing medical protein. Affinity magnetic nano-beads is covered with the medical protein after agitation of solvent containing the protein and nano-beads, then the solvent flows through the system and the beads are trapped in the filters by high gradient magnetic field. The beads are released and flow out of the system by the AC demagnetization of the filters using LC resonance circuits after discharge of the magnet. The test results shows 97.8% of the magnetic nano-beads in pure water were captured and 94.1% of total beads were collected.

DOI： 10.1063/1.4860832

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Influence of Winding Accuracy on Magnetic Field Distribution in YBCO Pancake Coil for Cyclotron Application Reviewed

Tao Wang, Hiraku Karino, Kenta Michitsuji, Xudong Wang, Atsushi Ishiyama, Hiroshi Ueda, Mitsuhiro Fukuda, Tomonori Watanabe, Shigeo Nagaya

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY 24 ( 3 ) 9002005 2014.6

Language：English Publishing type：Research paper (scientific journal) Publisher：IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC

In recent years, YBCO high-temperature superconducting (HTS) tapes have been expected to be applied to devices in power systems or in other industrial applications, owing to their rapidly improving quality and productivity. Our objective is to develop an HTS cyclotron with a compact body, high efficiency of output power, and high performance in heavy particle radiotherapy. In such an application, extremely high precision is required in the range 0.01% to 0.1% of magnetic field, both spatially and temporally. An isochronous field along with an azimuthally varying field is generated by an air-core pancake coil system during construction. Therefore, developing a technology for extremely high coil-winding accuracy is very important. In this study, we constructed an experimental model of a YBCO pancake coil using a high-precision coil winding machine. Then, the winding error in the radial and axial directions was experimentally evaluated using a pair of laser displacement meters and a surface roughness tester. We also developed a numerical simulation model to analyze the influence of winding error on the magnetic field distribution. The relationship between the winding error and the magnetic field of the meter-class YBCO coil assuming a real system was also evaluated by numerical simulation.

DOI： 10.1109/TASC.2013.2297317

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Measurement and Simulation of Magnetic Field Generated by Screening Currents in HTS Coil Reviewed International journal

Hiroshi Ueda, Mitsuhiro Fukuda, Kichiji Hatanaka, Kenta Michitsuji, Hiraku Karino, Tao Wang, Xudong Wang, Atsushi Ishiyama, So Noguchi, Yoshinori Yanagisawa, Hideaki Maeda

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY 24 ( 3 ) 4701505 2014.6

Authorship：Lead author,　Corresponding author Language：English Publishing type：Research paper (scientific journal) Publisher：IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC

In coils wound with high-temperature superconducting (HTS) tapes, large screening currents are induced in the tape by the radial component of the magnetic field. Furthermore, when a transport current is supplied to the HTS tape under a magnetic field, the total current (which consists of the transport and screening currents) flows inhomogeneously. The magnetic field generated by the screening currents affects the magnetic field distribution in cyclotron applications. Investigating the effects of the screening currents on the reduction, hysteresis, and drift of the magnetic field in the HTS coil is therefore necessary. In our previous studies, we have developed a novel simulation code for a three-dimensional electromagnetic field with the aim of clarifying these effects. In the present study, we measured the reduction and hysteresis of the magnetic field generated by the screening currents for a small model of HTS pancake coil. Additionally, we numerically investigated the influence of the screening current in the Furs coil on the spatial and temporal behavior of the magnetic field using our developed simulation code, which considers the nonlinear voltage-current characteristics.

DOI： 10.1109/TASC.2014.2299537

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Development of Degaussing System of Magnetic Filters for High Gradient Magnetic Separation to Improve Recovery Ratio of Trapped Magnetic Nanobeads Reviewed

Kazuhiro Kajikawa, Hiroshi Ueda, Yasuharu Kamioka, Koh Agatsuma, Shuichiro Fuchino, Mitsuho Furuse, Tomohiro Iitsuka, Shuichi Nakamura

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY 24 ( 3 ) 4400305 2014.6

Language：English Publishing type：Research paper (scientific journal) Publisher：IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC

We have successfully developed a high-gradient magnetic separation system for medical proteins using affinity magnetic nanobeads. Our system shows very high separation efficiency and can also be expected to realize lower cost due to larger production rate compared to the conventional system. The developed system consists of a 3-T superconducting magnet and a filter made of fine magnetic metal fibers. The superconducting magnet is wound with a NbTi twisted multifilamentary wire, and cooled by a 4-K Gifford-McMahon cryocooler. In order to achieve high recovery ratio of the magnetic nanobeads trapped on the filter located in a room-temperature clear bore of the cryostat, the ac degaussing system for the filter is fabricated using an inductance capacitance resonance circuit composed of a series connection with the superconducting magnet and an additional capacitor. To perform the inductance capacitance resonance more than a few cycles between superconducting magnet and capacitor, the superconducting magnet has a slit in the bobbin to prevent an eddy current coupled with an alternating magnetic field. It also has a control system for a high-speed switching circuit. This magnet can successfully generate a magnetic field of 3.0 T in the clear bore of the cryostat with a diameter of 30 mm in a relatively fast sweep time of 150 s due to the slit in the magnet bobbin. Using our degaussing system, a high recovery ratio of the nanobeads in pure water has been performed about 94.1%.

DOI： 10.1109/TASC.2013.2281364

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Development of Superconducting High Gradient Magnetic Separation System for Medical Protein Separation Reviewed

Shuichiro Fuchino, Mitsuho Furuse, Koh Agatsuma, Yasuharu Kamioka, Tomohiro Iitsuka, Shuichi Nakamura, Hiroshi Ueda, Kazuhiro Kajikawa

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY 24 ( 3 ) 4400204 2014.6

Language：English Publishing type：Research paper (scientific journal) Publisher：IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC

Medical proteins such as monoclonal antibodies and immunoglobulins are important substances for the manufacture of medicines for cancer, etc. However, the conventional separation system for these medical proteins has very low separation rate and the cost is extremely high. To address these issues, we have developed a high gradient magnetic separation system for medical proteins using affinity magnetic nanobeads. Our system shows very high separation efficiency and can achieve low cost owing to its large production rate compared with conventional systems. The system consists of a 3T superconducting magnet cooled by a cryocooler, a filter made of fine magnetic metal fibers of about 30 mu m in diameter with demagnetization circuit and liquid circulation pump for the solvent containing the medical proteins. Reducing the size of the system entails reduction of the cryocooler size, thereby resulting in reduced cooling capacity. Therefore, the heat load on the cryocooler has been considered carefully in the design of the cryogenic system. The calculated heat load of the 1st and 2nd stages was made to satisfy the cooling capacity of the cryocooler. As a result, a magnet temperature of 4.2 K and a thermal shield temperature of 60 K have been achieved, enabling smooth operation and good performance of the HGMS separation system.

DOI： 10.1109/TASC.2013.2281020

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Present Status of the RCNP Cyclotron Facility

K. Hatanaka, M. Fukuda, K. Kamakura, S. Morinobu, T. Saito, H. Tamura, H. Ueda, Y. Yasuda, T. Yorita

Proceedings of the 20th International Conference on Cyclotrons and their Applications 40 - 42 2014.3

Developments of Ion Source Complex for Highly Intense Beam at RCNP

T. Yorita, M. Fukuda, K. Hatanaka, K. Kamakura, S. Morinobu, A. Tamii, H. Ueda, Y. Yasuda

Proceedings of the 20th International Conference on Cyclotrons and their Applications 189 - 191 2014.3

Development of a New Active-Type Gradient Corrector for an AVF Cyclotron

M. Fukuda, N. Hamatani, K. Hatanaka, K. Kamakura, S. Morinobu, K. Nagayama, T. Saito, H. Tamura, H. Ueda, Y. Yasuda, T. Yorita

Proceedings of the 20th International Conference on Cyclotrons and their Applications 230 - 232 2014.3

Developments of HTS Magnets at RCNP

K. Hatanaka, M. Fukuda, K. Kamakura, S. Takemura, H. Ueda, Y. Yasuda, K. Yokoyama, T. Yorita, T. Kawaguchi

Proceedings of the 20th International Conference on Cyclotrons and their Applications 242 - 244 2014.3

Development of Rapid Emittance Measurement System

K. Kamakura, M. Fukuda, N. Hamatani, K. Hatanaka, M. Kibayashi, S. Morinobu, K. Nagayama, T. Saito, H. Tamura, H. Ueda, H. Yamamoto, Y. Yasuda, T. Yorita

Proceedings of the 20th International Conference on Cyclotrons and their Applications 171 - 173 2014.3

Studies of extraction and transport system for highly charged ion beam of 18 GHz superconducting electron cyclotron resonance ion source at Research Center for Nuclear Physics Reviewed

T. Yorita, K. Hatanaka, M. Fukuda, H. Ueda, Y. Yasuda, S. Morinobu, A. Tamii, K. Kamakura

REVIEW OF SCIENTIFIC INSTRUMENTS 85 ( 2 ) 02A741 2014.2

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER INST PHYSICS

An 18 GHz superconducting electron cyclotron resonance ion source is installed to increase beam currents and to extend the variety of ions especially for highly charged heavy ions which can be accelerated by cyclotrons of Research Center for Nuclear Physics (RCNP), Osaka University. The beam production developments of several ions from B to Xe have been already done [T. Yorita, K. Hatanaka, M. Fukuda, M. Kibayashi, S. Morinobu, H. Okamura, and A. Tamii, Rev. Sci. Instrum. 79, 02A311 (2008) and T. Yorita, K. Hatanaka, M. Fukuda, M. Kibayashi, S. Morinobu, H. Okamura, and A. Tamii, Rev. Sci. Instrum. 81, 02A332 (2010)] and the further studies for those beam extraction and its transport have been done in order to increase the beam current more. The plasma electrode, extraction electrode, and einzel lens are modified. Especially extraction electrode can be applied minus voltage for the beam extraction and it works well to improve the extracted beam current. The extraction voltage dependences of transmission and emittance also have been studied for beam current improvement which is injected into azimuthally varying field cyclotron at RCNP. (C) 2014 AIP Publishing LLC.

DOI： 10.1063/1.4849675

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