Faculty Profiles - UEDA Hiroshi

Papers - UEDA Hiroshi

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Improvement of a High-Gradient Magnetic Separation System for Trapping Immunoglobulin in Serum Reviewed International journal

Hiroshi Ueda, Koh Agatsuma, Shuichiro Fuchino, Tomohiro Imura, Mitsuho Furuse, Kazuhiro Kajikawa, Atsushi Ishiyama, Tatsuo Koizumi, Shinichiro Miyake

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY 20 ( 3 ) 949 - 952 2010.6

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

Recently, affinity magnetic beads have been widely used in immunomagnetic cell sorting (IMCS) technology. Today, we can easily sort and analyse DNA and antibodies (immunoglobulin) using various types of affinity magnetic beads available in the market. The diameters of the affinity magnetic beads used in immunomagnetic cell sorting are above approximately 1 mu m because of the low magnetic fields induced by permanent magnets. At present, nanosized affinity magnetic beads are strongly desired to achieve high resolutions. We have been studying and attempting to develop a high-gradient magnetic separation (HGMS) system that employs a superconducting magnet to induce a considerably higher magnetic field than that induced by a permanent magnet. The objective is to trap smaller nanosized affinity magnetic beads using a filter made of fine stainless steel wool. In a previous study, we constructed a prototype of a desktop-type HGMS system using a cryocooler-cooled LTS magnet; we conducted preliminary experiments on trapping nanosized magnetic particles and investigated the magnetic field distribution and magnetic force around a magnetic wire in the filter by means of a numerical simulation.
In this study, we succeeded in producing prototype nanobeads covered with the biosurfactant of a high-affinity ligand system for immunoglobulin G and M. Furthermore, we attempted to improve the recovery of nanobeads by adding a resonance circuit to the HGMS system. In practice, the trapped nanobeads attract one another and agglomerate due to their remaining magnetization when the magnetic field is decreased to 0 T. Therefore, the nanobeads and wire are demagnetized in the AC magnetic field by the resonance circuit, making good use of the superconducting magnet of the HGMS system.

DOI： 10.1109/TASC.2010.2040158

Thermal Characteristics of 275 kV/3 kA Class YBCO Power Cable Reviewed

Xudong Wang, Hiroshi Ueda, Atsushi Ishiyama, Masashi Yagi, Takashi Saitoh, Yuji Aoki, Noboru Fujiwara

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY 20 ( 3 ) 1264 - 1267 2010.6

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

In Japan, the development of a 275 kV/3 kA class YBa(2)Cu(3)O(7) (YBCO) power cable was started in 2008. A high-temperature superconducting (HTS) power cable typically consists of a copper former, HTS conductor layers, an electrical insulation layer, HTS shield layers, and copper shield layers. 275 kV/3 kA class YBCO power cables may be subjected to a fault current of 63 kA(rms) for 0.6 s. Therefore, in order to ensure stability and feasibility of superconducting power cables, we need to investigate the thermal characteristics and current distribution in the cable under fault conditions. In this study, we performed numerical simulations on a YBCO model cable under fault conditions by using a computer program we developed on the basis of 3D finite element method (FEM) and electrical circuit model.

DOI： 10.1109/TASC.2010.2041642

Numerical Simulation of Critical Current Performance in Nb3Sn Strand Subjected to Periodic Bending Deformation Reviewed

Haruyuki Murakami, Hiroshi Ueda, Atsushi Ishiyama, Norikiyo Koizumi, Kiyoshi Okuno

ELECTRICAL ENGINEERING IN JAPAN 171 ( 3 ) 7 - 15 2010.5

Language：English Publishing type：Research paper (scientific journal) Publisher：WILEY-BLACKWELL

In the ITER Engineering Design Activity (EDA), four NB3Sn model coils were developed and successfully tested. However, it was revealed that the critical current of the conductor degraded with the increase of electromagnetic force. One of the explanations of this phenomenon is a strand bending caused by enormous electromagnetic force. The authors therefore developed a simulation code using the distributed circuit model to investigate dependency of the critical current performance on the periodic bending deformation. The simulation results were in good agreement with the experiments. The dependence of the critical current on the periodic transverse load, temperature, periodic load pitch, thickness of Ta barrier which prevents Cu stabilizer from being contaminated by Sn, twist pitch of the strand, and RRR of the bronze matrix was investigated using the developed code. The results showed that the critical current degraded less with decreasing the pitch of the transverse load and increasing the Ta barrier thickness. It suggests that the shorter cabling pitch and the larger bending stiffness prevent the critical current degradation. (C) 2010 Wiley Periodicals, Inc. Electr Eng Jpn, 171(3): 7-15, 2010; Published online in Wiley Inter Science (www.interscience.wiley.com). DOI 10.1002/eej.20923

DOI： 10.1002/eej.20923

Over-current characteristics of YBCO superconducting cable Reviewed

X. Wang, H. Ueda, A. Ishiyama, M. Yagi, S. Mukoyama, N. Kashima, S. Nagaya, Y. Shiohara

PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS 469 ( 15-20 ) 1717 - 1721 2009.8

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE BV

To achieve large current capacity and high mechanical flexibility, YBa(2)Cu(3)O(7) (YBCO) superconducting cables consist of a number of YBCO coated conductors that are assembled and wound spirally on a Cu former. In practical applications, superconducting cables are vulnerable to short-circuit fault currents that are 10-30 times greater than the operating current. Therefore, in order to ensure the stability of YBCO superconducting cables in such a situation and to protect them from the fault currents, it is important to investigate the redistribution of the transport current and electromagnetic coupling between the conductor layer, shield layer, and Cu former. In this study, we carried out experiments on a 10-m-long YBCO model cable, which was manufactured by Furukawa Electric. An over-current with a peak of 31.8 kA(rms) and a duration of 2.02 s was applied to the model cable. We performed numerical simulations using a novel computer program developed using the 3D finite element method to elucidate the electromagnetic and thermal behavior of the YBCO model cable in the presence of an over-current. (C) 2009 Published by Elsevier B.V

DOI： 10.1016/j.physc.2009.05.034

Design and Test of Filter of High Gradient Magnetic Separation System for Trapping Immunoglobulin in Serum Reviewed International journal

Hiroshi Ueda, Koh Agatsuma, Kazuhiro Kajikawa, Mitsuho Furuse, Shuichiro Fuchino, Atsushi Ishiyama

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY 19 ( 3 ) 2157 - 2161 2009.6

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

Recently, affinity magnetic beads have been widely used in immunomagnetic cell sorting (IMCS) technology. Today, we can easily sort and analyze DNA and antibodies (immunoglobulin) using various types of affinity magnetic beads available in the market. The diameters of these affinity magnetic beads used in immunomagnetic cell sorting are limited to above approximately 1 because of the low magnetic fields induced by permanent magnets. Now, nano-sized affinity magnetic beads are strongly desired to achieve high resolutions. We have been studying and attempting to develop a high-gradient magnetic separation (HGMS) system that employs a superconducting magnet to induce a considerably higher magnetic field than that induced by a permanent magnet in order to trap smaller nano-sized affinity magnetic beads by a filter made of fine stainless steel wool. In this study, we constructed a prototype of a desktop-type HGMS system using a cryocooler-cooled LTS magnet and conducted preliminary experiments on trapping the nano-sized magnetic particles. Furthermore, we investigated the magnetic field distribution and magnetic force around a magnetic wire in the filter by means of a numerical simulation.

DOI： 10.1109/TASC.2009.2018441

Accurate Position Control of Active Magnetic Levitation Using Sphere-Shaped HTS Bulk for Inertial Nuclear Fusion Reviewed

Yoshihiro Ishigaki, Hiroshi Ueda, Koh Agatsuma, Atsushi Ishiyama

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY 19 ( 3 ) 2133 - 2136 2009.6

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

We have been developing an active magnetic levitation system, which is composed of a field-cooled disk-shaped or sphere-shaped high-temperature superconducting bulks (HTS bulks) and vertically piled ring-shaped electromagnets without an iron core. We suppose that this active magnetic levitation system can be applied to inertial nuclear fusion. In inertial nuclear fusion, one of the most important issues is to achieve high-accuracy position control of the fusion fuel, which consists of deuterium and tritium in order to evenly illuminate the entire surface of the target. Therefore, active magnetic levitation is applied to the levitation and position control of a sphere-shaped superconducting capsule containing nuclear fusion fuel. In this study, we designed and constructed a three-coil position control system in order to achieve the stable levitation of the sphere-shaped HTS bulk with a diameter of 5 mm by using the numerical simulation based on the hybrid finite element and boundary element analysis. Then, we carried out the experiments on the position control and restoring force characteristics of the sphere-shaped HTS bulk in the constructed levitation system.

DOI： 10.1109/TASC.2009.2017898

Over-Current Characteristics of a 20-m-Long YBCO Model Cable Reviewed

Xudong Wang, Hiroshi Ueda, Atsushi Ishiyama, Masashi Yagi, Shinichi Mukoyama, Masayoshi Ohya, Takato Masuda, Naoji Kashima, Shigeo Nagaya, Yuh Shiohara

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY 19 ( 3 ) 1722 - 1726 2009.6

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

To achieve large current capacity and mechanical flexibility, high-temperature superconductor (HTS) power transmission cables consist of a number of YBCO coated conductors, which are assembled and wound spirally on a Cu former. In practical applications, superconducting cables might be subjected to short-circuit fault currents that are 10 to 30 times the operating current. Therefore, in order to ensure the stability and feasibility of HTS power cables and protect them from fault currents, it is important to estimate the redistribution of the transport current and electromagnetic coupling among the conductor layer, shield layer, and Cu former. In this study, we carried out experiments on a 20-m-long YBCO model cable, which was composed of two jointed 10-m-long YBCO model cables. Over-current with a peak of 31.8 kA(rms) and a duration of 2.02 s was applied to the model cable. We performed numerical simulations using a newly developed computer program based on the 3D finite element method (FEM) in order to clarify the electromagnetic and thermal behaviors of the YBCO model cable in the presence of an over-current.

DOI： 10.1109/TASC.2009.2018316

Degradation Characteristics of YBCO-Coated Conductors Subjected to Overcurrent Pulse Reviewed

Atsushi Ishiyama, Yukiyasu Nishio, Hiroshi Ueda, Naoji Kashima, Masami Mori, Tomonori Watanabe, Shigeo Nagaya, Masashi Yagi, Shinichi Mukoyama, Takato Machi, Yuh Shiohara

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY 19 ( 3 ) 3483 - 3486 2009.6

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

YBCO tapes are expected to be used in future high temperature superconducting (HTS) applications because of their good characteristics at high temperatures and in high applied magnetic fields. In applications to electric power devices such as transmission cables, transformers, and fault current limiters, the HTS conductors will be subjected to short-circuit fault currents that are 10 to 30 times the normal operating current. These overcurrents are greater than the critical current, and degrade or burn-out the HTS conductors. Therefore, it is important to clarify the mechanism of the degradation caused by such overcurrent pulses. We carried out preliminary experiments on damage caused by overcurrent pulse drive, focusing on the temperature limitation without suffering degradation for overcurrent pulse operation. A 10-mm-wide YBCO tape was cut into 2-mm-wide sample tapes by a laser beam, and the sample tapes were soldered on silver-deposited 100-thick copper plates. Overcurrent tests were carried out on these sample tapes and I(c) degradation was investigated. In addition the contact interface between YBCO and the Ag layer or buffer layer before and after the overcurrent drives has been investigated in order to clarify the correlation between the degradation and delamination of sample tapes.

DOI： 10.1109/TASC.2009.2018734

Radioactivity of YBCO and Bi-2223 Tapes Under Low Energy Neutron Flux Reviewed International journal

Hiroshi Ueda, Atsushi Ishiyama, Nobuyuki Miyahara, Naoji Kashima, Shigeo Nagaya

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY 19 ( 3 ) 2872 - 2876 2009.6

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

The quality of high-temperature superconductors ( HTSs) is rapidly increasing, and they can be used in power systems such as SMES systems and in industries as Si single-crystal growth pullers. In the future, HTS conductors are expected to be used for the magnets in nuclear fusion reactors or accelerators. In such applications, HTS conductors will be exposed to radiation. As a result, HTS conductors become radioactive making the operation and maintenance of the reactors or accelerators difficult; this also leads to an increase in the amount of nuclear waste generated. Therefore, we carry out experiments on the radiation damage in HTS conductors to study the characteristics of HTS conductors in radiation environments and to create an industrial database of the radiation effects on HTSs. We also carry out radioactive analyses on HTS conductors in order to clarify the relationship between the irradiation dose and the activity of HTS conductors. In this study, we prepared YBCO and Bi-2223 tapes and carried out the following preliminary experiments: ( a) irradiation of the sample HTS tapes with 2-MeV neutrons at room temperature without transport current and (b) study of neutron-induced radioactivity by gamma-ray spectrometry using a Ge detector after the irradiation.

DOI： 10.1109/TASC.2009.2017713

Numerical simulation of critical current performance in Nb<inf>3</inf>Sn strand subjected to periodic bending deformation Reviewed

Murakami, H., Ueda, H., Ishiyama, A., Koizumi, N., Okuno, K.

IEEJ Transactions on Power and Energy 128 ( 6 ) 853 - 859 2008.6

Transient stability characteristics of a 1-m single-layer YBCO cable Reviewed International journal

Atsushi Ishiyama, Xudong Wang, Hiroshi Ueda, Masashi Yagi, Shinichi Mukoyama, Naoji Kashima, Shigeo Nagaya, Yuh Shiohara

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY 18 ( 2 ) 1228 - 1231 2008.6

Language：English Publishing type：Research paper (international conference proceedings) Publisher：IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC

YBCO tapes are expected to be used in future high temperature superconductor (HTS) applications as they have better J(c) characteristics at high temperatures and in high magnetic fields. For power applications such as transmission cables, YBCO tapes and a copper former are connected in parallel and they might be subjected to a short-circuit fault current that is 10 to 30 times the normal operating current. Therefore the over-current behavior, including the hot-spot and the distribution of transport current between the copper-laminated YBCO tapes and the copper former, is very important to examine the stability and feasibility of the cable. This paper describes the experimental results for over-current pulses of a 1-m single-layer cable fabricated with five copper-laminated YBCO tapes and a copper former. Further, we performed numerical simulations by using a newly developed computer program based on the 3D finite element method.

DOI： 10.1109/TASC.2008.920610

Assessment of Cryogenic Thermography System Using Commercial Fluorescent Paints on Their Applicability to Visualization of Normal-Zone Propagation in YBCO Coated Conductor Reviewed International journal

Atsushi Ishiyama, Motokazu Tsuchiya, Hiroshi Ueda, Yuh Shiohara

IEEE Transactions on Applied Superconductivity 17 ( 2 ) 3765 - 3768 2007.6

Authorship：Lead author Language：English Publishing type：Research paper (scientific journal) Publisher：Institute of Electrical and Electronics Engineers (IEEE)

To establish a stability criterion for YBCO coated conductors, it is required to clarify their transient thermal characteristics. In this study, we adopt a method for visualization of. temperature distribution using fluorescent paints whose color changes depending on the temperature. In the visualization method, firstly, commercial fluorescent paints are coated on the surface of sample strips. And then, the sample is irradiated by a black light or UV-LEDs, and the image of the fluorescence is observed by a CCD camera. These captured images are manipulated image processing by a computer, and show the temperature distribution. This system can be applied to cryogenic and high magnetic field circumstances. By adopting this visualization method to the investigation of transient thermal characteristics of YBCO tapes, local heat generation in the YBCO tapes can be observed by higher resolution, and it is expected to identify the uniformity of critical current density of YBCO tapes. In this paper, we describe the developed thermal visualization system and the preliminary experimental results on visualization of normal-zone initiation and propagation in YBCO sample strip fabricated with IBAD/PLD method.

DOI： 10.1109/tasc.2007.899124

Degradation of YBCO Coated Conductors Due to Over-Current Pulse Reviewed International journal

Atsushi Ishiyama, Yasutake Tanaka, Hiroshi Ueda, Yuh Shiohara, Takato Machi, Yasuhiro Iijima, Takashi Saitoh, Naoji Kashima, Masami Mori, Tomonori Watanabe, Shigeo Nagaya

IEEE Transactions on Applied Superconductivity 17 ( 2 ) 3509 - 3512 2007.6

Transient Stability Characteristics of Parallel-Connected YBCO Coated Conductors for Power Transmission Cables Reviewed International journal

Atsushi Ishiyama, Takuya Iwata, Hiroshi Ueda, Shinichi Mukoyama, Yuh Shiohara

IEEE Transactions on Applied Superconductivity 17 ( 2 ) 1672 - 1675 2007.6

Development of Pipeline Transporter System Using Pinning Effect of High-Temperature Superconducting Bulks Reviewed International journal

H.. Ueda, M.. Tsuchiya, A.. Ishiyama

IEEE Transactions on Applied Superconductivity 17 ( 2 ) 2323 - 2326 2007.6

Authorship：Lead author Language：English Publishing type：Research paper (scientific journal) Publisher：Institute of Electrical and Electronics Engineers (IEEE)

We have been developing a pipeline transporter system using high-temperature superconducting bulks (HTS bulks). In this paper, we propose a pipeline transporter system using pinning effect of HTS bulks. This system has the advantage of the application in harsh or dangerous environment such as in hazardous gas. This system requires large lateral force at the certain gap between the permanent magnets and the HTS bulks. For the realization of this pipeline transporter system, we investigated the influences of the arrangement of HTS bulks and permanent magnets on the lateral force characteristics through experiments and numerical simulations by using a computer program based on the three-dimensional hybrid finite element and boundary element (3D hybrid FE-BE) method. And we also designed a model system with a lateral force of 1500 N.

DOI： 10.1109/tasc.2007.899966

A Criterion for Determining Stabilizer Thickness of YBCO Coated Conductors Based on Coil Protection Reviewed International journal

Atsushi Ishiyama, Hiroshi Ueda, Taketoshi Ando, Hironori Naka, Sadanori Bamba, Yuh Shiohara

IEEE Transactions on Applied Superconductivity 17 ( 2 ) 2430 - 2433 2007.6

Language：English Publishing type：Research paper (scientific journal) Publisher：Institute of Electrical and Electronics Engineers (IEEE)

The purpose of this study is to propose a criterion for determining stabilizer thickness of YBCO coated conductors. The permissible disturbance energy density in high-temperature superconductors (HTSs) is two or three orders of magnitude greater than that in low-temperature superconductors (LTSs). On the other hand, to enhance the reliability and safety of HTS colls, an establishment of a protection scheme assuming a quench caused by a failure in power supply, cooling system or similar problem is also required for HTS coil systems. Quenching produces excessive temperature or voltage in the coil winding; overheating may cause the conductor to meltdown, or high voltage may punch a hole in the winding. To avoid these types of damages in YBCO coils, a suitable stabilizer thickness must be determined for the sophisticated structure of YBCO coated conductors, which are composed of highly textured thin-film on a flat flexible substrate. Therefore, we investigate the appropriate structure for YBCO coated conductors from the perspective of energy dumping (i.e., quench protection). Based on the protection scheme that the stored magnetic energy in the coils is dumped by an external dump resistance prepared as a quench protection, we derive a function that examines the heat balance of a quenching YBCO coil in an adiabatic condition and propose a criterion using the function to determine an appropriate stabilizer thickness for YBCO coated conductors. © 2007 IEEE.

DOI： 10.1109/tasc.2007.897998

Numerical Simulation of Critical Current and n-Value in ${\rm Nb}_{3}{\rm Sn}$ Strand Subjected to Bending Strain Reviewed International journal

H. Murakami, A. Ishiyama, H. Ueda, N. Koizumi, K. Okuno

IEEE Transactions on Applied Superconductivity 17 ( 2 ) 1394 - 1397 2007.6

Language：English Publishing type：Research paper (scientific journal) Publisher：Institute of Electrical and Electronics Engineers (IEEE)

Critical current of ITER model coil degraded with the increase of electromagnetic force. Analysis based on results of the experiments in which periodic transverse load is artificially applied to single strand showed that periodic bending of the strand by transverse load caused this degradation. However, since the experiments were carried out under a certain condition, general relation between transverse load and critical current was not obtained. We have therefore developed a numerical simulation code to investigate the general relation. However, there were some disagreements between the simulation and experimental results in our previous study. Our simulation model was consequently modified, resulting in good agreement with the test results. The general dependence of the critical current on periodic transverse load, temperature, and pitch of periodic load is investigated using the modified simulation code. The simulation results reveal that the reduced critical current depends on the temperature, and is a function of the bending strain independent of the pitch of the periodic load. © 2007 IEEE.

DOI： 10.1109/tasc.2007.898113

Fundamental characteristics and 3D electromagnetic analysis for magnetic levitation transporter using YBCO superconductors Reviewed International journal

Hiroshi Ueda, Mami Iwamoto, Yuhya Kudo, Atsushi Ishiyama

ELECTRICAL ENGINEERING IN JAPAN 159 ( 2 ) 44 - 54 2007.4

Authorship：Lead author,　Corresponding author Language：English Publishing type：Research paper (scientific journal) Publisher：SCRIPTA TECHNICA-JOHN WILEY & SONS

A magnetic levitation device with two-dimensional movement, the so-called "levitating X-Y transporter," has been developed. In order to develop a working levitating X-Y transporter, it is necessary to clarify the levitation characteristics, such as the lift force, levitation height, and stability against mechanical disturbances. In this paper, we examine the lift and the restoring force experimentally and propose a new simulation program based on the three-dimensional hybrid finite and boundary element method to analyze the dynamic behavior of electromagnetic characteristics of YBCO bulk. Using the numerical simulation and experiments, we investigated a suitable arrangement of permanent magnets to enhance the levitation characteristics. We also designed a levitating transporter which can carry a load of 200 kg with a gap of 16 mm. (C) 2007 Wiley Periodicals, Inc.

DOI： 10.1002/eej.20220

Numerical simulation of the critical current and n-Value in Nb <inf>3</inf>Sn strand subjected to bending strain Reviewed International journal

Hirohashi, M., Murakami, H., Ishiyama, A., Ueda, H., Koizumi, N., Okuno, K.

IEEE Transactions on Applied Superconductivity 16 ( 2 ) 1721 - 1724 2006.6

3D Electromagnetic Analysis of Levitating Transporter Using Bulk Superconductor Reviewed International journal

H. Ueda, S. Azumaya, S. Tsuchiya, A. Ishiyama

IEEE Transactions on Applied Superconductivity 16 ( 2 ) 1092 - 1095 2006.6

Authorship：Lead author,　Corresponding author Language：English Publishing type：Research paper (scientific journal) Publisher：Institute of Electrical and Electronics Engineers (IEEE)

We have constructed and demonstrated levitating transporter models composed of the superconductor bulks (HTS bulks) and permanent magnets. The dynamic characteristics of lift force, lateral force and magnetic stiffness are very important for the design of superconducting devices such as a levitation system. The electromagnetic phenomenon should be clarified through the accurate analyses of the magnetic field and shielding current distributions within HTS bulks. In this study, we developed a new simulation program based on the three-dimensional hybrid finite element and boundary element (3D hybrid FE-BE) method, which combines with the fast multipole method (FMM). By using the FMM, it is possible to solve the large-scale problem with a reduction of the required memory size and improvement of the accuracy. This simulation program can consider the anisotropic and nonlinear E - J characteristics of HTS bulks. The results of experiment and numerical simulation are in good agreement. © 2006 IEEE.

DOI： 10.1109/tasc.2006.871280

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