氏名

イシヤマ アツシ

石山 敦士

職名

教授 (https://researchmap.jp/read0078136/)

所属

(先進理工学部)

連絡先

メールアドレス

メールアドレス
atsushi@waseda.jp

URL等

WebページURL

http://www.super.elec.waseda.ac.jp

https://researchmap.jp/read0078136(researchmap連携中)

研究者番号
00130865

本属以外の学内所属

兼担

理工学術院(大学院先進理工学研究科)

研究院(研究機関)/附属機関・学校(グローバルエデュケーションセンター)

社会科学総合学術院(大学院社会科学研究科)

学内研究所等

理工学総合研究センター

兼任研究員 1989年-2006年

先端バイオ研究所

プロジェクト研究所所長 2006年-2006年

バイオサイエンス連携研究所(COBRI)

プロジェクト研究所所長 2008年-2011年

先進グリッド技術研究所

研究所員 2010年-2014年

早稲田バイオサイエンスシンガポール研究所

プロジェクト研究所所長 2017年-2018年

先進グリッド技術研究所

研究所員 2014年-2016年

早稲田バイオサイエンスシンガポール研究所

プロジェクト研究所所長 2016年-2016年

早稲田バイオサイエンスシンガポール研究所

研究所員 2016年-2016年

理工学術院総合研究所(理工学研究所)

兼任研究員 2006年-2018年

理工学術院総合研究所(理工学研究所)

兼任研究員 2018年-

早稲田バイオサイエンスシンガポール研究所

研究所員 2017年-2018年

先進グリッド技術研究所

研究所員 2016年-2019年

先進グリッド技術研究所

研究所員 2019年-

学歴・学位

学歴

-1977年 早稲田大学 理工学部 電気工学
-1983年 早稲田大学 理工学研究科 電気工学

学位

工学博士 課程 早稲田大学 電力工学・電力変換・電気機器

経歴

1979年04月-1983年03月早稲田大学助手
1983年04月-1985年03月早稲田大学専任講師
1985年04月-1991年03月早稲田大学助教授
1991年04月-早稲田大学教授

所属学協会

低温工学・超電導学会 執行理事、学会誌出版委員長

日本生体磁気学会 理事

電気学会

研究分野

キーワード

電気機器・超伝導応用・電磁界数値解析・生体磁気

科研費分類

工学 / 電気電子工学 / 電力工学・電力変換・電気機器

共同研究希望テーマ

脳の高次機能に関する研究

希望連携機関:産学連携、民間を含む他機関等との共同研究等

目的:共同研究

研究テーマ履歴

超伝導マグネット技術に関する研究

研究テーマのキーワード:超伝導マグネット,安定性,設計

国内共同研究

電気機器の最適化設計に関する研究

研究テーマのキーワード:電磁界解析,最適化設計,電気機器

機関内共同研究

生体磁気計測に関する研究

研究テーマのキーワード:超伝導量子干渉素子,脳磁図,心磁図

国内共同研究

超電導応用機器

個人研究

電磁界解析

個人研究

電気機器の最適化設計

個人研究

生体磁気計測

個人研究

論文

Influence of coil size and operating temperature on the transient stability of a multi-stacked no-insulation REBCO pancake coil system

Haruka Onoshita, Yuka Yoshihara, Hiroshi Ueda, So Noguchi, and Atsushi Ishiyama

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY30(4)2020年06月-2020年06月 

DOI

詳細

ISSN:1051-8223

概要:The no-insulation (NI) coil is a technology expected to realize both high current density and high thermal stability which are essentially trade-off relationship in REBCO coil application. This technique has been studied mainly for application to small-diameter inner coils of NMR magnets exceeding 30 T. In this case, the coil is cooled using 4.2-K liquid He. We are developing an NI-REBCO coil system for high-magnetic-field whole-body MRI, and for a medical cyclotron to be used for cancer therapy. The NI-REBCO coil which we aim for development has a diameter of ~1 m, a generated magnetic field is ~10 T, and a conduction cooling around 30 K is assumed. Because the size, operating temperature, and magnetic field differ from those of NMR coil, it is possible that the electromagnetic, thermal, and mechanical behaviors will be quite different. In this paper, we report on these behaviors when a local deterioration occurs in NI-REBCO double-pancake coils us-ing numerical analysis considering coil size, operating temperature, and magnetic field as parameters. For the numerical simulation, we conducted a coupled analysis of current distribution analysis based on PEEC (Partial Element Equivalent Circuit) model and thermal analysis by the 2-dimensional finite element method.

Evaluation of Electromagnetic Behavior of No-Insulation REBCO Pancake Coil With Multiple Defects

Yuta Kakimoto , Tetsuri Ichikawa, Haruka Onoshita, Tetsuro Kinpara, Atsushi Ishiyama, and So Noguchi

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY29(5)2019年08月-2019年08月 

DOI

詳細

ISSN:10518223

概要:We previously developed a high-magnetic-field RE-BCO coil for use in medical devices such as medical accelerators and high-magnetic-field MRI. The use of high-temperature supercon-ducting (HTS) coils in such applications necessitates their minia-turization while providing high magnetic fields. However, when the current density is improved by reducing the copper-stabilization-layer thickness in the conventional insulated HTS coil, the thermal stability is lowered, which leads to a tradeoff between high cur-rent density and high thermal stability. Therefore, we examine no-insulation (NI) coils that allow compatibility between high current density and thermal stability. Recent research has indicated that NI coils with multiple defects can afford a stable and high critical current (Ic) and operate without serious problems, which makes it possible to produce coils wound with commercial REBCO tapes containing several defects along the tape, which in turn makes fab-rication economically viable. However, there are many unknown aspects of the current, magnetic field, and heat behaviors of NI coils with defects, particularly when large currents flow through them. Here, in order to examine the behavior of a multiple-defect NI coil subjected to a large current at the temperature of ∼30 K via application of the conduction cooling method, we use a com-bination of the partial element equivalent circuit method and the finite-element method to investigate the detailed current and ther-mal behaviors. Our results indicate that defective NI coils can af-ford a critical current Ic value of ∼80% of that of defect-free NI coils, which makes our findings valuable in terms of contributing to further developments in HTS coil applications.

Conceptual Design of Compact HTS Cyclotron for RI Production

Hiroshi Ueda , Member, IEEE, Atsushi Ishiyama, So Noguchi , Tomonori Watanabe , Shigeo Nagaya, Jun Yoshida, and Mitsuhiro Fukuda

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY29(5)2019年08月-2019年08月 

DOI

詳細

ISSN:10518223

概要:In autumn 2017, the project “Quantum Innovation for Safe and Smart Society (QiSS)” was started in Program on Open Innovation Platform with Enterprises, Research Institute and Academia (OPERA) by Japan Science and Technology Agency (JST). One of the key issues of this project is the advancement of compact cyclotron and beam irradiation device for stable supply of short-lived radioisotope (RI). We proposed the air-core cyclotron using high-temperature superconducting (HTS) technology, named Skeleton Cyclotron, as high intensity compact cyclotron. Currently, we are carrying out a feasibility study on a variable-energy multi-particle Skeleton Cyclotron for RI production. In this paper, key issues in HTS magnet technologies for Skeleton Cyclotron and the preliminary conceptual design of variable-energy multi-particle Skeleton Cyclotron are reported.

Comparison Between Simulation and Experimental Results of Liquid Nitrogen Coolant Distribution in a 66-kV 40-m Model HTS Power Cable System Experiencing Short-Circuit Accidents

Daichi Horita, Koh Agatsuma, Atsushi Ishiyama, Takato Masuda, Toshiya Morimura , and Tomoo Mimura

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY査読有り29(5)2019年08月-2019年08月 

DOI

詳細

ISSN:10518223

概要:In this study, a computer program was developed to simulate the temperature and pressure distributions of a liquid ni-trogen (LN) coolant in a high-temperature superconducting (HTS) power cable. This program is important for realizing a practical HTS power cable. According to the Japanese criterion for a 66-kV power-transmission system, in a worst case short-circuit accident, a fault current of 31.5 kA may flow in a 66-kV cable system for 2 s. In addition, when a short-circuit accident occurs, the temperature and pressure of an LN coolant increase rapidly The temperature behaviors of the cable cores and coolant were analyzed by solving the nonlinear partial differential heat-conduction equations in the cable cores by considering the energy balance of the heat flow by using the finite-difference method. Moreover, the pressure behav-iors of the coolant in a cooling system were analyzed, considering the density and volume behaviors of the coolant. The simulation results for the 66-kV 40-m model cable qualitatively reproduced the experimental results satisfactorily.

Experiments on the Effects of Local Normal Transitions in Multi-Stacked No-Insulation REBCO Pancake Coils

Tetsuri Ichikawa, Yuta Kakimoto, Haruka Onoshita, Tetsuro Kinpara, So Noguchi , Shigeo Nagaya, Tomonori Watanabe , and Atsushi Ishiyama

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY29(5)2019年08月-2019年08月 

DOI

詳細

ISSN:10518223

概要:No-insulation (NI) coils are an important technique for high-field magnetic resonance imaging (MRI). One of the tech-nical issues with NI coils is their thermal and electromagnetic be-havior when a local normal transition occurs. Given that multiple stacked coils are used in MRI, the interaction between coils must also be investigated, because a local normal transition may affect the other NI coils through magnetic coupling. In fact, when a local normal transition occurs, there is a possibility that large electro-magnetic forces are applied to the other coils, or quench may be induced in some of them. Even though overcurrent tests of stacked NI coils have been conducted, the results are not helpful in ac-tual MRI operation. In this study, we investigate the effects of the occurrence of a local normal transition in multi-stacked NI coil systems under conditions similar to those of actual operation, with a constant transport current below the coil’s Ic . The occurrence of a local normal transition is simulated by applying current to a heater inserted in manufactured small NI double pancake coils. To evaluate the interaction between NI coils, the voltage and changes in the generated magnetic field are measured at each coil. We also show the current distribution in the coils, as obtained by the partial element equivalent circuit method. The obtained results allow us to evaluate the interaction of the NI coils and evaluate coil protection methods.

A simple screening current-induced magnetic field estimation method for REBCO pancake coils

So Noguchi, Hiroshi Ueda, Seungyong Hahn, Atsushi Ishiyama and Yukikazu Iwasa

Superconductor Science and Technology査読有り322019年03月-2019年03月 

link

詳細

概要:The development of NMR/MRI REBa2Cu3Oy (REBCO, RE = rare earth) magnets is happening all over the world. It has been found that screening current-induced magnetic fields (SCMFs) are a serious problem for NMR/MRI magnets wound with REBCO tapes. The reduction of SCMFs is strongly desired, and the estimation of SCMFs is also desired at the design stage of REBCO magnets. In order to evaluate a SCMF, a finite element method (FEM) or a boundary integration method is needed thus far, and a high-level simulation technique is required. In this paper, we develop an easy method to estimate a SCMF without a high-level simulation technique. In this method, the inductance of a winding turn is calculated and then a screening current is estimated according to the magnetic field penetrating into the winding turn. The SCMF is obtained from the estimated screening current. The SCMFs computed by the proposed method were compared with measurements and simulation results of the FEM. The results agreed well, but we can see a large difference. However, the SCMFs found by the proposed method are accurate enough to know they are at the design stage without the use of a high-level simulation technique.

REBCOコイルにおける遮蔽電流不整磁場の抑制効果解析ー9.4T級ヒト全身用MRIコイルを対象としてー

伊東慶太、植田浩史、野口聡、石山敦士

低温工学・超電導学会誌 低温工学54(2)p.119 - 1262019年03月-2019年03月 

詳細

概要:Since high critical-current density can be maintained in a high magnetic field, a multi-coil system composed of REBCO superconducting tape is expected to be applied to MRis and medical accelerators. We have been developing a REBCO coil system for 9.4-T whole-body M町. InM町s, magnetic-field homogeneity with high precision in time and space is required in the imaging space, and in this reseru·ch and development, the target values are set to I ppm/h and JO ppm, respectively. In REBCO coils, screening currents are remru·kably induced in the winding tape by the perpendiculru· component of the magnetic field to the wide face of the REBCO tapoe,. ge:enerratin g an irregular magnet field that deteriorates the magnetic-field homogeneity. Therefore, in order to realize a coil system satisfying MRI specifications, it is required to accurately predict and reduce this shielding-current magnetic field. ln this paper, we repmt results of detailed analysis and evaluation of the influence of the shielding-current magnetic field, and examine a method and procedure for reducing it. First, in order to improve the temporal stability, we evaluated the effect when the overshoot and the demagnetization methods are applied to control operation current, and optimize current waveform. Next, as a method to enhance the spatial homogeneity, we adopted a tape scribing technique by narrowing the tape width, and evaluated its effect, and optimized the coil-winding region to be scribed. Finally, we confirmed the effect of combining both current control and scribing, and showed that the target values of I ppm/h and JO ppm can be cleru·ed as a result.

無絶縁REBCO パンケーキ・ コイルにおける数値解析技術― 解析手法の比較および解析事例ー

野口聡、植田浩史、石山敦士

低温工学・超電導学会誌 低温工学54(2)p.103 - 1102019年03月-2019年03月 

詳細

概要:A no-insulation(NI)winding technique was proposed by Hahn. This technique drastically improves the thermal stability of REBCO pancake coils. Using the technique, a 45.5-T DC field was achieved at the National High Magnetic Field Laboratory in August 2018. Now, Iw邸a, of the Plasma Science and Fusion Center, Massachusetts Institute of Technology, is developing an insert NI REBCO magnet for the 1.3-GHz LTS/HTS NMR magnet. However, since the electromagnetic behavior in NI REBCO pancake coils is complicated, it is desirable to evaluate the magnet stability using simulation. Hence, a few simulation methods for NI REBCO pancake coils have been developed and reported, such as a lmnped circuit model, a partial element equivalent circuit (PEEC) model, and a distributed network model. In this review paper, we discuss tl1ese simulation methods and describe the specifications for each of them. Finally, we compare the simulation results of each method. Accurate simulation of the lumped circuit model and radially-divided circuit model with a small number of elements was not possible because the magnet coupling between elements or coils w邸 not correctly modeled. As a result, we had to use the PEEC model, distributed network model, or a radially-divided circuit model with many elements in order to accurately express the normal zone propagation.

高温超電導応用機器の数値解析技術の現状

植田浩史、野口聡、石山敦士

低温工学・超電導学会誌 低温工学54(2)p.89 - 962019年03月-2019年03月 

詳細

概要: High-temperature superconducting(HTS) wires such as those used for Bi-2223 and REBCO tapes, which are com­mercially available, are expected to be used in future electric power devices and high-field magnets because of their good critical­current characteristics at high temperatures and in high applied magnetic fields. Therefore, the importance ofnumerical simulation techniques for HTS applications has increased. Recently, special sessions on numerical simulation of HTS modeling and applica­tions have been held at academic conferences and workshops. Generally, the electromagnetic phenomena including HTS materials use the eddy current problem of Maxwell's equations together with nonlinear constitutive relationships between the electric field and current density. Until now, the user him/herselfhad to code a special program in order to manage the modeling of HTS materials and formulations of elecn·omagnetic phenomena including HTS materials. However, recently, the numerical simulation on HTS applications using commercial software has been reported. In this paper, the current status of numerical simulation techniques for HTS applications is reviewed.

A simple protection evaluation method for no-insulation REBCO pancake coils during local normal-state transition

So Noguchi, Seungyong Hahn, Atsushi Ishiyama and Yukikazu Iwasa

Superconductor Science and Technology査読有り322019年02月-2019年02月 

link

詳細

概要:No-insulation (NI) and metal-insulation (MI) winding techniques are promising for enhancing the thermal stability of REBCO pancake coils, toward the practical use of nuclear magnetic resonance and magnetic resonance imaging systems. The NI and MI REBCO pancake coils showed high thermal stability in many over-current tests. However, a disadvantage is a charging delay due to low turn-to-turn contact resistance. Therefore, many researchers have tried to increase turn-to-turn contact resistance to overcome the charging delay problem. Meanwhile, a partial element equivalent circuit (PEEC) model can accurately simulate the over-current and charging/discharging tests of NI REBCO pancake coils in detail. Using the PEEC model coupling with thermal finite element analysis (FEA), the thermal stability was evaluated during a local normal-state transition. From the simulation results, it was found that a best range of turn-to-turn contact resistance existed to keep a high thermal stability during a local normal-state transition. However, the PEEC and thermal FEA method requires a substantial amount of time with complicated simulation approach. In this paper, we propose a simple mathematical formulation to obtain an appropriate range of turn-to-turn contact resistance during a local normal-state transition, supposing a worst cooling condition. The simple computation is easy to use and timesaving to roughly estimate the operation reliability of NI REBCO pancake coils.

Safety Verification of a 275-kV HTS Cable System under Short-Circuit Current Accidents

Yokoo, Yusuke; Takeda, Natsuo; Horita, Daichi; Agatsuma, Koh; Ishiyama, Atsushi; Wang, Xudong; Takagi, Tomohiro; Yagi, Masashi

IEEE Transactions on Applied Superconductivity28(4)2018年06月-2018年06月 

DOIScopus

詳細

ISSN:10518223

概要:© 2018 IEEE. A simulation code that analyzes the temperature and pressure in a high-temperature superconducting (HTS) power cable cooled by a forced flow of subcooled liquid nitrogen (LN) has been developed. Analysis of the HTS cable is useful for comprehending the normal operating condition and the generation of heat during the transient state. In Japan, an excessive current of 63 kA may flow in an HTS cable for 0.6 s in the worst case when a short-circuit current accident occurs in a 275-kV class cable. To assess the safety under this condition, a simulation of a 275-kV class 20-m model cable was performed, and the simulation results of the temperature profiles qualitatively agreed with the experimental results. In this study, a finite-difference method was used to solve the nonlinear partial differential equations of the heat-transfer phenomenon through heat conduction. By solving these equations, the temperature profiles of the LN coolant and the cable cores were analyzed. The GASPAK software package (Cryodata) was used to evaluate the fluid properties when the LN temperature in the cable was calculated. According to this result, the simulations focused on the analysis of a real-scale HTS cable in this work.

Thermal and Electromagnetic Simulation of Multistacked No-Insulation REBCO Pancake Coils on Normal-State Transition by PEEC Method

Miyao, Ryosuke; Igarashi, Hajime; Ishiyama, Atsushi; Noguchi, So; Noguchi, So; Noguchi, So

IEEE Transactions on Applied Superconductivity28(3)2018年04月-2018年04月 

DOIScopus

詳細

ISSN:10518223

概要:© 2017 IEEE. This paper presents the thermal and electromagnetic behaviors of multistacked no-insulation (NI) REBa 2 Cu 3 O 7- x (REBCO, RE = rare earth) pancake coils. The NI winding technique gives a high enough thermal stability not to damage REBCO coils even though a normal-state transition occurs. The high thermal stability has been verified through overcurrent tests. Moreover, the numerical simulation of multistacked NI REBCO pancake coils has been performed to investigate the electromagnetic behaviors in detail. The simulation results also confirmed the high thermal stability of NI REBCO pancake coils. However, it does not mean that an NI REBCO magnet never quenches. In experiments, it was observed that a quench in one of the pancake coils propagated to the other pancake coils sequentially. The above sequential quench from pancake to pancake has not been confirmed in the numerical simulation since the thermal behavior is not considered. For the more reliable verification, we have developed a numerical simulation to investigate the thermal and electromagnetic behaviors by the partial element equivalent circuit method and the two-dimensional thermal finite-element method. In this paper, the six-stacked NI REBCO pancake coil is simulated with several operating temperatures, and the sequential quench is reproduced. The velocity of the sequential quench is also shown.

An Extended Thin Approximation Method to Simulate Screening Current Induced in REBCO Coils

Noguchi, So; Noguchi, So; Hahn, Seungyong; Hahn, Seungyong; Ueda, Hiroshi; Kim, Seokbeom; Ishiyama, Atsushi

IEEE Transactions on Magnetics54(3)2018年03月-2018年03月 

DOIScopus

詳細

ISSN:00189464

概要:© 2017 IEEE. Superconducting magnets wound with second-generation high-temperature superconductors, i.e., REBa 2 Cu 3 O 7-x (REBCO, RE = Rare Earth) tapes, are desired to apply high magnetic field nuclear magnetic resonance, MRI, and accelerators. However, a major problem for practical application is an undesirable irregular magnetic field caused by screening currents induced in REBCO tapes. To investigate the screening current-induced magnetic field, a few simulation methods have been proposed. One of the effective simulation methods employs a finite-element method with a thin approximation method. Although the thin approximation method was developed to simulate eddy currents in magnetic steel sheets, and it is not applicable to REBCO tapes carrying a transport current. Therefore, the thin approximation method is extended to simulate screening currents in REBCO tapes considering a carrying transport current. To show the validity of the proposed extended thin approximation method, the screening currents of an REBCO magnet are computed, and the results are compared with the measurement and simulation results of the conventional thin approximation method. The more accurate solution is available by using the proposed methods.

Magnetoencephalography Reveals Mismatch Field Enhancement from Unexpected Syntactic Category Errors in English Sentences

Kubota, Mikio; Kubota, Mikio; Kubota, Mikio; Ono, Yumie; Ono, Yumie; Ono, Yumie; Ishiyama, Atsushi; Zouridakis, George; Papanicolaou, Andrew C.; Papanicolaou, Andrew C.

Neuroscience Letters662p.195 - 2042018年01月-2018年01月 

DOIScopus

詳細

ISSN:03043940

概要:© 2017 Elsevier B.V. The type of syntactic operations that increase neuronal activation in humans as a result of syntactically erroneous, unexpected lexical items in hearing sentences has remained unclear. In the present study, we used recordings of magnetoencephalographic (MEG) activity to compare bare infinitive and full infinitive constructions in English. This research aims to identify the type of syntactic deviance that may trigger an early syntax-related mismatch field (MMF) component when unexpected words appear in sentences. Six speakers of English as a first language were presented with auditory stimuli of sentences or words in a passive odd-ball paradigm while watching a silent movie. The experimental protocol included four sessions, specifically investigating the sentential (structural) versions of full (with the ‘to’ infinitival particle) and bare infinitival structures (without the particle) and the lexical (non-structure) versions of the verb either with or without the particle to determine whether the structure processing of sentences was a more crucial factor in the detection of the MMF than the simple processing of lexical items in verb-only conditions. The amplitude analysis of the resulting evoked fields showed that the presence of the syntactic category error of bare infinitival structures against syntactic predictions evoked a significantly larger MMF activation with a peak latency of approximately 200 ms in the anterior superior temporal sulci in the left hemisphere, compared with the lexical items that did not have any syntactic status. These results clearly demonstrate that syntactically unexpected, illegal input in the bare infinitival structure is likely to be noticed more robustly in the brain while processing the structural information of the entire sentence than the corresponding verb-only items.

A new thin approximation simulation method of screening current in REBCO tape considering tape's thickness

Noguchi, S.; Noguchi, S.; Ishiyama, A.; Ueda, H.

2017 IEEE International Magnetics Conference, INTERMAG 20172017年08月-2017年08月 

DOIScopus

詳細

概要:© 2017 IEEE. An extremely high field homogeneity is required for applications of NMR and MRI magnets.

Temperature Simulation of a 20 m HTS Power Model Cable System in a Fault Current for 275 kV Transmission Lines

Yokoo, Yusuke; Yasui, Tetsuo; Takeda, Natsuo; Agatsuma, Koh; Ishiyama, Atsushi; Wang, Xudong; Yagi, Masashi; Takagi, Tomohiro

IEEE Transactions on Applied Superconductivity27(4)2017年06月-2017年06月 

DOIScopus

詳細

ISSN:10518223

概要:© 2017 IEEE. A simulation has been developed for estimating the transient temperature and pressure distributions in a high-temperature superconducting (HTS) power cable with a fault current accident cooled by a forced flow of subcooled liquid nitrogen (LN 2 ). This simulation is an essential tool for realizing a practical HTS power cable in order to assess the effects of short-circuit accidents. When a fault occurs in a 275 kV class power transmission system in Japan, an excessive current of 63 kA may flow in the cable for 0.6 s. When faults occur, it is important to estimate the temperature and pressure profiles in a cable cooled by the forced flow of subcooled LN 2 . The temperature profiles of the LN 2 coolant and the cable cores were analyzed by solving nonlinear partial differential equations of the heat transfer phenomenon through heat conduction using finite-difference method. The GASPAK software package (Cryodata) was used to evaluate the fluid properties. The simulation results for 275 kV class 20 m model cable show fairly good agreement with the experimental results obtained by Fukukawa Electric.

Safety and Reliability of 66-kV Class HTS Cable Systems in Short-Circuit Current Accidents-Experimental Results on 40-m Cable System

Masuda, Takato; Morimura, Toshiya; Nakano, Tetsutaro; Maruyama, Osamu; Mimura, Tomoo; Yasui, Tetsuo; Agatsuma, Koh; Ishiyama, Atsushi

IEEE Transactions on Applied Superconductivity27(4)2017年06月-2017年06月 

DOIScopus

詳細

ISSN:10518223

概要:© 2002-2011 IEEE. High-temperature superconducting (HTS) cables can transmit large amounts of electricity in a compact size with minimal losses. Therefore, it expects to save the construction cost of underground lines in urban areas and decrease transmission losses. The stability and reliability of HTS cable systems in normal operation has been verified by real grid interconnection tests around the world. While general practical use of HTS cable systems requires the verification of their stability not only in normal operation but also in the event of various accidents (ground fault, short-circuit current, liquid nitrogen leakage, etc.) and understanding these phenomena and their impact. However, a few studies have been conducted to investigate the safety of HTS cable systems in the event of the accidents so far. Regarding the short-circuit current, the maximum current depends on the voltage class and grid conditions, and it was set as 31.5 kA for the 66 kV systems in Japan. In order to verify the phenomena and impact to the cable systems, a 40-m cable system was constructed and cooled by circulated subcooled liquid nitrogen (LN 2 ). After the initial critical current (Ic) measurement of the cable system, the short-circuit current tests were conducted with ac 28.5 kA for 0.6 s and 16 kA for 8.4 s. The former testing condition is almost simulated as the current of 31.5 kA and the latter one is as equivalent heat generation in the HTS cable to 31.5 kA for 2 s. As the initial state of LN 2 , temperature and pressure of the cable inlet were around 68 K and 0.26 MPaG. The measured temperature and pressure rises of the coolant were not so high to make some damage to the HTS cable. After these tests, the cable Ic was measured again and no damage was found.

Detection Method for a Local Normal-State Transition in a No-Insulation REBCO Pancake Coil

Wang, Tao; Katsumata, Kazuki; Ishiyama, Atsushi; Noguchi, So

IEEE Transactions on Applied Superconductivity27(4)2017年06月-2017年06月 

DOIScopus

詳細

ISSN:10518223

概要:© 2002-2011 IEEE. In this paper, we have proposed a detection method for detecting and locating a local normal-state transition in a meter-class no-insulation (NI) coil that is deployed in next-generation high-field magnetic resonance imaging scanners (MRIs), using a copper pickup coil. There are two schemes for detecting and locating the normal zone: one is a ring pickup coil assembled on the midplane of a central bore and the other consists of several sector pickup coils deployed on the coil winding, namely 'scanning pickup coil.' To verify the effectiveness of these detection methods, we performed a numerical simulation coupling consisting of a partial element equivalent circuit, a thermal analysis, and a magnetic field analysis. Based on the results of analyses, we reproduced the distributions of the temporal variations of the magnetic flux in the central bore and on the coil winding of the meter-class NI coil, and discussed the effectiveness of these pickup coil schemes for detecting and locating a local normal-state transition in a meter-class NI coil used in next-generation high-field MRIs.

Current Behavior Simulation in Stacked NI REBCO Pancake Coils during Local Normal-State Transition

Noguchi, So; Noguchi, So; Miyao, Ryosuke; Monma, Katsutoshi; Igarashi, Hajime; Ueda, Hiroshi; Ishiyama, Atsushi

IEEE Transactions on Applied Superconductivity27(4)2017年06月-2017年06月 

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ISSN:10518223

概要:© 2017 IEEE. This paper presents the current behavior and axial Lorenz force of stacked no-insulation (NI) REBa2Cu3O7-x (REBCO, RE = Rare Earth) double-pancake coils during local normal-state transition. The NI winding technique enhances the thermal stability and increases the engineering current density in REBCO pancake coils. The high thermal stability of NI REBCO coil has been verified in experiments of overcurrent test. In addition, the numerical simulations of NI REBCO single-pancake coils have been performed to confirm the high stability. However, REBCO magnets usually consist of some stacked double-pancake coils to generate a high magnetic field for practical applications. When a normal-state transition occurs in one of the stacked pancake coils, it may affect the other pancake coils. For the more reliable verification, the current and electromagnetic force behavior of stacked NI REBCO pancake coils during a normal-state transition should be simulated. To examine the stacked NI REBCO pancake coils, we extend the previously proposed partial element equivalent circuit (PEEC) model to deal with a few double-pancake coils. In this paper, an NI REBCO double-pancake coil and their three stacked coils are simulated by using the extended PEEC model.

Temperature and Pressure Simulations of 66 kV 40 m HTS Cable System in Short-Circuit Current Accidents Compared with Experimental Results

Takeda, Natsuko; Yasui, Tetsuo; Yokoo, Yusuke; Agatsuma, Koh; Ishiyama, Atsushi; Wang, Xudong; Wang, Xudong; Masuda, Takato; Morimura, Toshiya; Mimura, Tomoo

IEEE Transactions on Applied Superconductivity27(4)2017年06月-2017年06月 

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ISSN:10518223

概要:© 2002-2011 IEEE. A numerical analysis program has been developed to simulate the transient temperature and pressure distribution in an high-temperature superconducting (HTS) power cable cooled by a forced flow of subcooled LN 2 during a short-circuit current accident. This computer simulation program includes computations of temperature and pressure profiles not only in the HTS power cable itself, but also in the cooling system, including the circulation pump. In 2015, Sumitomo Electric Industries demonstrated a 66 kV 40 m model cable with a fault current test, during which the void between the copper conductors of the copper former was filled by insulation material. In this study, simulations of the model cable were performed by considering that LN 2 is not absorbed in the copper former. This simulation was found to more precisely match experimental data by considering the rise in LN 2 temperature at the inlet and transient value of the thermal conductivity of the dielectric layer.

Progress of Yoroi-Coil Structure in Mechanical Strength with High Current Density

Watanabe, Tomonori; Nagaya, Shigeo; Hirano, Naoki; Awaji, Satoshi; Oguro, Hidetoshi; Ishiyama, Atsushi; Hojo, Masaki; Nishikawa, Masaaki

IEEE Transactions on Applied Superconductivity27(4)2017年06月-2017年06月 

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ISSN:10518223

概要:© 2002-2011 IEEE. Yoroi-coil (Y-based oxide superconductor and reinforcing outer integrated coil) structure has been developed to fabricate very strong pancake coils against electromagnetic force. In Yoroi-coil structure, the outer supporting structure is effective to make a mechanically robust coil having a high current density in the case that the hoop stress must exceed the yield strength of a REBCO-coated conductor without this reinforcement. By the experiments and analysis, we pointed out that the remarkably weak delamination stress can cause the delamination of the coated conductor in coils. So that Yoroi-coil structure has advantages to delamination because it could maintain a coil shape with reinforcing materials, without impregnation. Since higher current density is required by various applications, the Yoroi-coil using austenitic stainless steel reinforcing frames and plates, has been verified by the hoop stress test with high current density. Then, high coil current density of 446 A/mm 2 was achieved by the Yoroi-coil-structured double pancake (DP) coil, with the total number of the winding turns of 574, at 4.2 K in the back-up magnetic field of 11 T. The inner and outer diameters of the DP coil were 190 and 250.1 mm, respectively. Although the hoop stress evaluated on the assumption of excluding the supporting structure exceeds 1 GPa, Yoroi-coil structure restricted the strain of coil winding ranging 0.2% to 0.3%. The stainless steel reinforcing member well supported a part of electromagnetic force in Yoroi-coil structure, even with high coil current density.

Numerical Evaluation on Irregular Field Generated by Screening Current in High-Field REBCO Coil for Whole-Body MRI

Nakazono, Kohei; Ueda, Hiroshi; Ishiyama, Atsushi; Noguchi, So; Miyazaki, Hiroshi; Tosaka, Taizo; Kurusu, Tsutomu; Nomura, Shunji; Urayama, Shinichi; Fukuyama, Hidenao

IEEE Transactions on Applied Superconductivity27(4)2017年06月-2017年06月 

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ISSN:10518223

概要:© 2002-2011 IEEE. In recent years, high-field magnets wound with REBCO tape and their applications to magnetic resonance imaging (MRI) have undergone considerable research and development. MRI coil systems require a highly accurate field in the imaging space. However, in REBCO coils, the irregular magnetic field generated by the screening current is induced by the radial component of the magnetic field in the REBCO tape, and may deteriorate the field quality both spatially and temporally. Therefore, a design process with consideration for the effect of the screening-current field is required for the reduction and correction of this field for a high-accuracy-field REBCO coil. In this study, the screening-current distribution in the REBCO tape and the irregular magnetic field were analyzed by using the simulation we developed for a REBCO model coil system for whole-body MRI. We additionally discuss the effect of the screening-current field in the REBCO coil based on the coil shape and arrangement to use it as feedback to the design stage.

Screening-Current-Induced Magnetic Field of Conduction-Cooled HTS Magnets Wound with REBCO-Coated Conductors

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

IEEE Transactions on Applied Superconductivity27(4)2017年06月-2017年06月 

DOIScopus

詳細

ISSN:10518223

概要:© 2017 IEEE. Superconducting magnets for magnetic resonance imaging systems require homogeneous, stable magnetic fields. The homogeneity of the magnetic field is highly dependent on the coils shape and positions. Furthermore, in REBa 2 Cu 3 O 7-δ (REBCO) magnets, the screening-current-induced magnetic field, which changes the magnetic field distribution of the magnet, is one of the most critical issues. In the work described here, a small REBCO coil that can generate a magnetic field of over 10 T was fabricated and tested. The small REBCO coil was composed of a stack of 22 single pancake coils whose inner and outer diameters were 50 mm and 130 mm, respectively. The total conductor length was 1.5 km. The small REBCO coil could generate a central magnetic field of 8.27 T at 10 K. A magnetic field of over 10 T was achieved by replacing 12 of the single pancake coils with new ones wound with the latest REBCO-coated conductors. The measured value of the central magnetic field at 10 K was 13.53 T, which was lower than the calculated value of 13.94 T obtained without taking account of the screening-current-induced magnetic field. Furthermore, it was examined whether the current sweep reversal would be effective for 10 T-class magnetic field conditions.

Progress in the Development of Conduction-Cooled REBCO Magnets for Ultrahigh-Field MRI Systems

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

IEEE Transactions on Applied Superconductivity27(4)2017年06月-2017年06月 

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詳細

ISSN:10518223

概要:© 2017 IEEE. We started developing REBa 2 Cu 3 O 7-δ (REBCO) magnets for ultrahigh-field magnetic resonance imaging (MRI) systems in 2013. Our final targets are 9.4 T MRI systems for whole-body and brain imaging. In this paper, a conduction-cooled 1.5 T REBCO MRI magnet having a room-temperature bore of 396 mm was fabricated and tested in order to evaluate the magnetic field homogeneity and stability. The magnet was composed of 60 single pancakes whose inner diameter was 500 mm. The total conductor length was 10.3 km, and the total inductance was 12.4 H. The size of the homogeneous magnetic field region was 200 mm diameter spherical volume. The central magnetic field was as high as 1.5 T at 192.7 A, and the current density of single pancakes was 301 A/mm 2 . The magnet was cooled from room temperature to 4.7 K in 55 hours, and the temperature difference among the coils was 0.1 K or less during both initial cooling and excitation. The magnetic field inhomogeneity was 249.7 parts per million (ppm), and the Z 2 coefficient was largest at 579.6 ppm. The main reason for the error magnetic field was dimensional errors in the positions on the z-axis. The magnetic field inhomogeneity was improved to 4.1 ppm by passive shimming using iron pieces. The magnetic field stability was about 2 ppm/h because of a reduction in screening-current induced in the REBCO-coated conductors. Current sweep reversal improved the magnetic field stability from 2 ppm/h to 0.8 ppm/h.

Temperature and Pressure Distribution Simulations of 3-km-Long High-Temperature Superconducting Power Cable System with Fault Current for 66-kV-Class Transmission Lines

Yasui, Tetsuo; Takeda, Natsuko; Yokoo, Yusuke; Agatsuma, Ko; Ishiyama, Atsushi; Wang, Xudong; Masuda, Takato; Morimura, Toshiya; Mimura, Tomoo

IEEE Transactions on Applied Superconductivity27(4)2017年06月-2017年06月 

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詳細

ISSN:10518223

概要:© 2017 IEEE. A computer program has been developed by numerically solving the nonlinear heat conduction and heat transfer equations, which are discretized using the finite difference method, to calculate the temperature and pressure distributions in high-temperature superconducting (HTS) power cables cooled using liquid nitrogen (LN 2 ). The LN 2 coolant properties are estimated using Cryodata's GASPAK software package. This evaluation of the temperature and pressure distributions is important to understand how we can make practical use of HTS power cables and to assess the effects of short-circuit accidents. To incorporate HTS power cables into real grids, it is necessary to evaluate HTS power cables that are a few kilometers long. In this study, 3-km-long HTS cables were evaluated using our proposed computer program. This program was used to model the cooling system, ac loss, dielectric loss, and intermediate-joint losses. The results revealed that the temperature of the LN 2 coolant at the cable outlet could reach the saturation temperature when a fault current of 31.5 kA flowed for 2 s (worst case for the 66-kV-class transmission lines in Japan). From the results, it was also clear that the effects of the ac loss, dielectric loss, and intermediate-joint losses on the increase in the temperature of the LN 2 coolant could not be ignored.

Numerical Evaluation of the Reinforcing Effect of the Advanced YOROI Coil Structure for the HTS Coil

Kashiwazaki, Yuji; Ishiyama, Atsushi; Wang, Xudong; Wang, Xudong; Ueda, Hiroshi; Ueda, Hiroshi; Watanabe, Tomonori; Nagaya, Shigeo

IEEE Transactions on Applied Superconductivity27(4)2017年06月-2017年06月 

DOIScopus

詳細

ISSN:10518223

概要:© 2002-2011 IEEE. REBCO coils applied to superconducting magnetic energy storage system, magnetic resonance imaging, medical accelerator, and so on, are expected to result in high efficiency and compactness due to the realization of higher magnetic field and current density. Because these devices require large coil radius, huge hoop stress 'BJR' (= magnetic field × current density × coil radius) is produced in the coil winding and the damage to these devices is likely to cause. In our previous study, we proposed a novel coil structure called the Y-based oxide superconductor and reinforcing outer integrated (YOROI) structure to achieve a high-strength REBCO pancake coil. The YOROI structure comprises upper and lower plates and the outer frame of the winding outer periphery. The frames are forcibly expanded by the superconducting coil winding situated inside when the coil winding is subjected to an electromagnetic force. The outer frame is connected to the upper and lower plates and transfers a part of the electromagnetic force from the coil winding to the reinforcing outer plates. The reinforcing outer plates then support the coil to suppress the coil deformation against the electromagnetic forces. The YOROI structure achieved the resistance to a maximum hoop stress of 2 GPa, which was calculated from the BJR in an excitation test at 4.2 K in 8-T backup fields. In this study, we investigated the effect of the stress control structure to realize the HTS coil with a mechanical strength of over 2 GPa using a three-dimensional finite-element structural analysis.

Influence of the Turn-to-Turn Contact Electrical Resistance on the Thermal Stability in Meter-Class No-Insulation REBCO Pancake Coils during a Local Normal-State Transition

Katsumata, Kazuki; Wang, Tao; Ishiyama, Atsushi; Noguchi, So; Monma, Katsutoshi; Nagaya, Shigeo; Watanabe, Tomonori

IEEE Transactions on Applied Superconductivity27(4)2017年06月-2017年06月 

DOIScopus

詳細

ISSN:10518223

概要:© 2017 IEEE. In magnetic resonance imaging and nuclear magnetic resonance applications, it is important that the high-temperature superconducting coils provide a high magnetic field in a miniaturized form factor. Our research group considers these requirements to be compatible with no-insulation (NI) coils in which the thickness of the Cu stabilization layer and the turn-to-turn contact electrical resistance are key parameters that enable both high current densities and high thermal stabilities. When the Cu stabilization layer is thin, the current density is impaired, but the thermal stability is improved. If the turn-to-turn contact electrical resistance is very large, then the characteristics of the NI REBCO coil approach the characteristics of conventional insulated coils, and the thermal stability may be degraded. However, when the turn-to-turn contact electrical resistance is large, the excitation delay time is reduced. In this study, we used a combination of the partial element equivalent circuit method and the finite element method to perform a current distribution and thermal analysis of the behavior of NI REBCO coils when a local normal-state transition occurs. We also considered the appropriate turn-to-turn contact electrical resistance that could shorten the excitation delay time as much as possible while still suppressing the formation of hotspots, which is a disadvantage of the NI REBCO coil.

Numerical Investigation of Metal Insulation Technique on Turn-to-Turn Contact Resistance of REBCO Pancake Coils

Noguchi, So; Noguchi, So; Miyao, Ryosuke; Monma, Katsutoshi; Igarashi, Hajime; Ishiyama, Atsushi

IEEE Transactions on Applied Superconductivity27(4)2017年06月-2017年06月 

DOIScopus

詳細

ISSN:10518223

概要:© 2002-2011 IEEE. No-insulation (NI) REBCO pancake coils show high thermal stability, however the charging delay is an issue. Hence, to improve the charging delay, it was proposed that a stainless steel (SUS) tape was cowound between turns, called 'metal-as-insulation' or 'metal-insulation (MI),' to increase the turn-to-turn contact resistivity. The MI technique could make the turn-to-turn contact resistivity approximately 50 times large compared to a conventional NI REBCO pancake coil. This paper reports a bypass current behavior on the cross section of MI REBCO pancake coil using two-dimensional finite element method. The influence of the SUS tape thickness, the MI material, and the number of SUS tapes on the turn-to-turn contact resistivity is investigated. As the result, it is clarified that the turn-to-turn contact resistivity strongly depends on the surface condition and number of SUS tapes.

核融合炉用CIC 導体の超伝導特性評価手法の開発

梶谷 秀樹, 石山 敦士, 我妻 洸, 村上 陽之, 辺見 努, 小泉 徳潔,

低温工学・超電導学会誌 低温工学51(3)p.71 - 782016年04月-2016年04月 

DOIlink

詳細

ISSN:0389-2441

概要:A cable-in-conduit (CIC) conductor using an Nb3Sn strand is applied to the ITER TF coil. The performance of CIC conductor was degraded due to electromagnetic force. This is because a strand in the conductor is subjected to periodically bending strain by electromagnetic force, which causes the performance to become degraded. Strands in the conductor touch each other in a complicated manner due to twisting and the electromagnetic force is transferred via another strand, which leads to complication of bending strain distribution in the conductor. The complicated bending strain distribution makes it difficult to simulate the conductor performance analytically. The author thus developed a new model to evaluate conductor performance using a periodically bent strand model developed in a past study. However, the calculated result showed some error when compared to actual measured results. This may be due to the difference of physical phenomenon between a single freely bent strand and a strand constricted by an adjacent strand in the conductor. The author thus redeveloped a calculation model taking this effect into account. As a result, conductor performance can be successfully simulated. This indicates that a more practical solution can be achieved in quantitative evaluation of conductor performance.

波状曲げ変形を受けたNb3Sn 素線の臨界電流特性評価手法の開発

梶谷 秀樹, 石山 敦士, 我妻 洸, 村上 陽之, 辺見 努, 小泉 徳潔

低温工学・超電導学会誌 低温工学50(12)p.608 - 6152016年02月-2016年02月 

DOIlink

詳細

ISSN:1880-0408

概要:A cable-in-conduit (CIC) conductor using Nb3Sn strand is applied to an ITER TF coil. The Nb3Sn strand in the conductor is periodically bent due to electromagnetic force, which causes degradation of performance. This degradation should be evaluated to predict conductor critical current performance. In a past study, a numerical simulation model was developed to evaluate the superconductivity of a periodically bent single strand. However, this model is not suitable for application to strands in the conductor because of the extensive calculation time required. The author thus developed a new analytical model with a much shorter calculation time to evaluate the performance of periodically bent strand. This new model uses the classical model concept of a high transverse resistance model (HTRM). The calculated results show good agreement with the test results of a periodically bent Nb3Sn strand in a ends fixed beam model while there was little error in the uniformly bent model under high transverse load due to the difference in bending moment distribution between the two models. However, for both cases, the newly developed model has a much shorter calculation time than that required for numerical simulation. This indicates that a more practical solution can be achieved when evaluating the performance of periodically bent strands. Thus, the model developed in this study can be applied to evaluation of the performance of conductor incorporating many strands.

Conceptual Design of Next Generation HTS Cyclotron

Ueda, H ; Fukuda, M ; Hatanaka, K ; Wang, T ; Wang, XD ; Ishiyama, A ; et al.

IEEE Transactions on Applied Superconductivity23(3)2013年06月-

DOI

Spatial and Temporal Behavior of Magnetic Field Distribution Due to Shielding Current in HTS Coil for Cyclotron Application

Ueda, H ; Fukuda, M ; Hatanaka, K ; Wang, T ; Ishiyama, A ; Noguchi, S

IEEE Transactions on Applied Superconductivity23(3)2013年06月-

DOI

Evaluation of Conduction Cooling Effect of Cryocooler-Cooled HTS Coils for SMES Application

Kotoyori, T ; Ohnishi, H ; Masui, Y ; Ishiyama, A ; et al.

IEEE Transactions on Applied Superconductivity23(3)2013年06月-

DOI

Development of 66 kV and 275 kV Class REBCO HTS Power Cables

Maruyama, O ; Ohkuma, T ; Masuda, T ; Ashibe, Y ; Mukoyama, S ; Yagi, M ; Saitoh, T ; Hasegawa, T ; Amemiya, N ; Ishiyama, A ; Hayakawa, N

IEEE Transactions on Applied Superconductivity23(3)2013年06月-

DOI

Development of High Strength Pancake Coil With Stress Controlling Structure by REBCO Coated Conductor

Nagaya, S ; Watanabe, T ; Tamada, T ; Naruse, M ; Kashima, N ; Katagiri, T ; Hirano, N ; Awaji, S ; Oguro, H ; Ishiyama, A

IEEE Transactions on Applied Superconductivity23(3)2013年06月-

DOI

Quench Detection Method for Cryocooler-Cooled YBCO Pancake Coil for SMES

Ohnishi, Hideaki; Ishiyama, Atsushi; Watanabe, Tomonori; et al.

IEEE Transactions on Applied Superconductivity23(3)2013年06月-

DOI

Critical Current Degradation in High-Temperature Superconducting Tapes Caused by Temperature Rise

Yazaki, S ; Karasawa, A ; Kotoyori, T ; Ishiyama, A ; Miyahara, N

IEEE Transactions on Applied Superconductivity23(3)2013年06月-

DOI

Status of a 275 kV Class REBCO Superconducting Cable Development

Mukoyama, S ; Yagi, M ; Mitsuhashi, T ; Nomura, T ; Ten, J ; Nakayama, R ; Ohkuma, T ; Maruyama, O ; Aoki, Y ; Saitoh, T ; Amemiya, N ; Ishiyama, A ; Hayakawa, N

IEEE Transactions on Applied Superconductivity23(3)2013年06月-

DOI

Experiments and Numerical Simulations on Local Degradation Characteristics of Coated Conductor Due to Overcurrent

Wang, Xudong; Wang, Tao; Ishiyama, Atsushi; et al.

IEEE Transactions on Applied Superconductivity23(3)2013年06月-

DOI

Visual and Auditory Stimuli Associated with Swallowing Activate Mirror Neurons: A Magnetoencephalography Study

Ushioda, T ; Watanabe, Y ; Sanjo, Y; Yamane, G ; Abe, S ; Tsuji, Y ; Ishiyama, A

DYSPHAGIA27(4)p.504 - 5132012年12月-

DOI

Quench Detection and Protection of Cryocooler-Cooled YBCO Pancake Coil for SMES

Ueda, Hiroshi; Ishiyama, Atsushi; Muromachi, Kazuki; et al.

IEEE Transactions on Applied Superconductivity22(3)2012年06月-

DOI

Current Margin of 275 KV Class HTS Power Cable With Joint Against Fault Current

Wang, Xudong; Kamiya, Yuji; Ishiyama, Atsushi; et al.

IEEE Transactions on Applied Superconductivity22(3)2012年06月-

DOI

Overcurrent Tests and Numerical Simulations on a 66-kV-Class RE123 High-Temperature Superconducting Model Cable

Wang, Xudong; Ishiyama, Atsushi; Ohya, Masayoshi; et al.

IEEE Transactions on Applied Superconductivity22(3)2012年06月-

DOI

Current Margin of 66 kV Class HTS Power Cable Against Fault Current

Wang, XD; Kojima, K ; Kanemitsu, M ; Ishiyama, A ; et al.

IEEE Transactions on Applied Superconductivity22(3)2012年06月-

Numerical analyses of the electromagnetic force acting on high-temperature superconducting power cables due to fault current

Wang, X.; Ishiyama, A.; Ohya, M.; et al.

SUPERCONDUCTOR SCIENCE & TECHNOLOGY25(5)2012年05月-

DOI

Progress of 275 kV-3 kA YBCO HTS cable

Yagi, M ; Mukoyama, S ; Amemiya, N ; Ishiyama, A ; et al.

PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS471(21-22)p.1274 - 12782011年11月-

DOI

Design and evaluation of 66 kV-class HTS power cable using REBCO wires

Ohya, M ; Yumura, H ; Masuda, T ; Amemiya, N ; Ishiyama, A ;Ohkuma, T.

PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS471(21-22)p.1279 - 12822011年11月-

DOI

Model Cable Tests for a 275 kV 3 kA HTS Power Cable

Mukoyama, S; Yagi, M; Yonemura, T; Nomura,T; Fujiwara, N; Ichikawa, Y; Aoki,Y; Saith T; Amemiya N; Ishiyama, A. Hayakawa, N

IEEE Trans. on Appl. Supercond.21(3)p.976 - 9792011年06月-

DOI

Evaluation of Positional Stability in Active Magnetic Levitation Using Spherical HTS Bulk for Inertial Nuclear Fusion

Wang, Tao; Ueda, Hiroshi; Agatsuma, Koh; Ishiyama, Atsushiet al.

IEEE Trans. on Appl. Supercond.21(3)p.1579 - 15832011年06月-

DOI

Effect of Neutron Irradiation on High-Temperature Superconductors

Aoki, Toru; Ueda, Hiroshi; Ishiyama, Atsushi; et al.

IEEE Trans. on Appl. Supercond.21(3)p.3200 - 32022011年06月-

DOI

Numerical Simulation of Current Distribution in Cable-in-Conduit Conductor for ITER TF Coil

H. Kajitani, A. Ishiyama, N. Koizumi,H. Murakami,H. Nakajima

IEEE Trans. on Appl. Supercond.21(3)p.1964 - 19682011年06月-

Degradation of YBCO Coated Conductors Due to an Over-Current Pulse

A.Ishiyama, M.Arai, H.Momotari, X.Wang, H.Ueda, T.Saito, Y.Aoki, M.Yagi, T.Machi, N.Fujiwara

IEEE Trans. on Appl. Supercond.21(3)p.3025 - 30282011年06月-

Current Margin Against the Fault Current in REBCO Coated Conductors

A. Ishiyama, H. Momotari, X. Wang, M.Arai, H.Ueda, M.Ohya,K.Ohmatsu,N. Fujiwara,

IEEE Trans. on Appl. Supercond.21(3)p.3033 - 30362011年06月-

Over-Current Characteristics of 275-kV Class YBCO Power Cable

A. Ishiyama, X. Wang, H. Ueda, T. Uryu,M. Yagi, N. Fujiwara

IEEE Trans. on Appl. Supercond.21(3)p.1017 - 10202011年06月-

DOI

Over-Current Characteristics of 66-kV RE123 HTS Power Cable

X. Wang, A. Ishiyama, M. Ohya, N. Fujiwara

IEEE Trans. on Appl. Supercond.21(3)p.1013 - 10162011年06月-

Quench Behavior and Protection in Cryocooler-Cooled YBCO Pancake Coil for SMES

A. Ishiyama, H. Ueda,Y. Aoki,K. Shikimachi,N.Hirano,S. Nagaya

IEEE Trans. on Appl. Supercond21(3)p.2398 - 24012011年06月-

Nostalgic music enhances asymmetry in EEG power

Hatano, Mari; Ishiyama, Atsushi; Kasai, Naoko; et al.

NEUROSCIENCE RESEARCH71(S)p.E269 - E2692011年-

DOI

The change of EEG regarding with settlement of memory

Jyo, Tetsu; Kawasaki, Minoru; Nojo, Hideki; Ishiyama, Atsushi;et al.

NEUROSCIENCE RESEARCH71(S)p.E278 - E2782011年-

DOI

Differences in delta wave power between spontaneous and passive perception of ambiguous figures

Nanjo, Tatsuya; Ishiyama, Atsushi; Kasai, Naoko; et al.

NEUROSCIENCE RESEARCH71(S)p.E173 - E1732011年-

DOI

Determination of stabilizer thickness for YBCO coated conductors based on coil protection

Kawai Y (Kawai, Y.)1, Ishiyama A (Ishiyama, A.)1, Ueda H (Ueda, H.)1, Nagaya S (Nagaya, S.)2, Shikimachi K (Shikimachi, K.)2, Hirano N (Hirano, N.)2

PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS470(20,Sp. Iss. SI)p.1865 - 18692010年11月-

Numerical simulation on fault current condition in 66 kV class RE-123 superconducting cable

Wang X (Wang, X.)1, Ueda H (Ueda, H.)1, Ishiyama A (Ishiyama, A.)1, Ohya M (Ohya, M.)2, Yumura H (Yumura, H.)2, Fujiwara N (Fujiwara, N.)3

PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS470(20,Sp. Iss. SI)p.1580 - 15832010年11月-

Design and evaluation of 66 kV class RE-123 superconducting cable

Minamino T (Minamino, T.)1, Ohya M (Ohya, M.)1, Yumura H (Yumura, H.)1, Masuda T (Masuda, T.)1, Nagaishi T (Nagaishi, T.)1, Shingai Y (Shingai, Y.)1, Wang X (Wang, X.)2, Ueda H (Ueda, H.)2, Ishiyama A (Ishiyama, A.)2, Fujiwara N (Fujiwara, N.)3

PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS470(20,Sp. Iss. SI)p.1576 - 15792010年11月-

Computer simulation of fault current characteristics in 275 kV class YBCO power cable

Sato S (Sato, S.)1, Wang X (Wang, X.)1, Ueda H (Ueda, H.)1, Ishiyama A (Ishiyama, A.)1, Yagi M (Yagi, M.)2, Mukoyama S (Mukoyama, S.)2, Saitoh T (Saitoh, T.)3, Aoki Y (Aoki, Y.)4, Fujiwara N (Fujiwara, N.)5

PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS470(20,Sp. Iss. SI)p.1572 - 15752010年11月-

Degradation characteristics of YBCO coated conductors due to fault-current in power cable applications

Kono H (Kono, H.)1, Wang X (Wang, X.)1, Ueda H (Ueda, H.)1, Ishiyama A (Ishiyama, A.)1, Saitoh T (Saitoh, T.)2, Aoki Y (Aoki, Y.)3, Yagi M (Yagi, M.)4, Mukoyama S (Mukoyama, S.)4, Fujiwara N (Fujiwara, N.)5

PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS470(20,Sp. Iss. SI)p.1334 - 13372010年11月-

Stability and Protection of Coils Wound With YBCO Bundle Conductor

Ueda H (Ueda, Hiroshi)1, Ishiyama A (Ishiyama, Atsushi)1, Shikimachi K (Shikimachi, Koji)2, Hirano N (Hirano, Naoki)2, Nagaya S (Nagaya, Shigeo)2

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY20(3)p.1316 - 13192010年06月-

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

Wang XD (Wang, Xudong)1, Ueda H (Ueda, Hiroshi)1, Ishiyama A (Ishiyama, Atsushi)1, Yagi M (Yagi, Masashi)2, Saitoh T (Saitoh, Takashi)3, Aoki Y (Aoki, Yuji)4, Fujiwara N (Fujiwara, Noboru)5

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY20(3)p.1264 - 12672010年06月-

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

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

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY20(3)p.949 - 9522010年-2010年

DOIWoS

詳細

ISSN:1051-8223

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

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

ELECTRICAL ENGINEERING IN JAPAN171(3)p.7 - 152010年-2010年

DOIWoS

詳細

ISSN:0424-7760

Appropriate frequency band of event related desynchronization (ERD) for motor-image BCI

Kawasaki, Minoru;Nojo, Hideki;Jyo, Tetsu;Ishiyama, Atsushi;Kasai, Naoko;Ono, Yumie

NEUROSCIENCE RESEARCH68p.E327 - E3272010年-2010年

DOIWoS

詳細

ISSN:0168-0102

Over-current characteristics of YBCO superconducting cable

Wang X (Wang, X.)1, Ueda H (Ueda, H.)1, Ishiyama A (Ishiyama, A.)1, Yagi M (Yagi, M.)2, Mukoyama S (Mukoyama, S.)2, Kashima N (Kashima, N.)3, Nagaya S (Nagaya, S.), Shiohara Y (Shiohara, Y.)4

PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS469(15-20)p.1717 - 17212009年08月-2009年10月 

Development of (RE)BCO cables for HTS power transmission lines

Mukoyama S (Mukoyama, S.)1, Yagi M (Yagi, M.), Masuda T (Masuda, T.)2, Amemiya N (Amemiya, N.)3, Ishiyama A (Ishiyama, A.)4, Kashima N (Kashima, N.)5, Nagaya S (Nagaya, S.)5, Aoki Y (Aoki, Y.)6, Yoshizumi M (Yoshizumi, M.)7, Yamada Y (Yamada, Y.)7, Izumi T (Izumi, T.)7, Shiohara Y (Shiohara, Y.)7

PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS469(15-20)p.1688 - 16922009年08月-2009年10月 

Degradation Characteristics of YBCO-Coated Conductors Subjected to Overcurrent Pulse

Ishiyama A (Ishiyama, Atsushi)1, Nishio Y (Nishio, Yukiyasu)1, Ueda H (Ueda, Hiroshi)1, Kashima N (Kashima, Naoji)2, Mori M (Mori, Masami)2, Watanabe T (Watanabe, Tomonori)2, Nagaya S (Nagaya, Shigeo)2, Yagi M (Yagi, Masashi)3, Mukoyama S (Mukoyama, Shinichi)3, Machi T (Machi, Takato)4, Shiohara Y (Shiohara, Yuh)4

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY19(3)p.3483 - 34862009年06月-

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

Ueda H (Ueda, Hiroshi)1, Ishiyama A (Ishiyama, Atsushi)1, Miyahara N (Miyahara, Nobuyuki)2, Kashima N (Kashima, Naoji)3, Nagaya S (Nagaya, Shigeo)3

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY19(3)p.2872 - 28762009年06月-

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

Ueda H (Ueda, Hiroshi)1, Agatsuma K (Agatsuma, Koh)2, Kajikawa K (Kajikawa, Kazuhiro)3, Furuse M (Furuse, Mitsuho), Fuchino S (Fuchino, Shuichiro)2, Ishiyama A (Ishiyama, Atsushi)1

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY19(3)p.2157 - 21612009年06月-

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

Ishigaki Y (Ishigaki, Yoshihiro)1, Ueda H (Ueda, Hiroshi)1, Agatsuma K (Agatsuma, Koh)1, Ishiyama A (Ishiyama, Atsushi)1

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY19(3)p.2133 - 21362009年06月-

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

Wang XD (Wang, Xudong)1, Ueda H (Ueda, Hiroshi)1, Ishiyama A (Ishiyama, Atsushi)1, Yagi M (Yagi, Masashi)2, Mukoyama S (Mukoyama, Shinichi)2, Ohya M (Ohya, Masayoshi)3, Masuda T (Masuda, Takato)3, Kashima N (Kashima, Naoji)4, Nagaya S (Nagaya, Shigeo)4, Shiohara Y (Shiohara, Yuh)5

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY19(3)p.1722 - 17262009年06月-

Increase of frontal delta activity related to perceptual switching

Okada M (Okada, Mayuko)1, Ono Y (Ono, Yumie)2, Ishiyama A (Ishiyama, Atsushi)1, Kasai N (Kasai, Naoko)1

NEUROSCIENCE RESEARCH65p.S174 - S1742009年-

Over-current characteristics of superconducting model cable using YBCO coated conductors

Ishiyama A (Ishiyama, A.)1, Wang X (Wang, X.)1, Ueda H (Ueda, H.)1, Yagi M (Yagi, M.)2, Mukoyama S (Mukoyama, S.)2, Kashima N (Kashima, N.)3, Nagaya S (Nagaya, S.)3, Shiohara Y (Shiohara, Y.)4

PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS468(15-20)p.2041 - 20452008年09月-

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

Ishiyama A (Ishiyama, Atsushi)1, Wang X (Wang, Xudong)1, Ueda H (Ueda, Hiroshi)1, Yagi M (Yagi, Masashi)2, Mukoyama S (Mukoyama, Shinichi)2, Kashima N (Kashima, Naoji)3, Nagaya S (Nagaya, Shigeo)3, Shiohara Y (Shiohara, Yuh)4

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY18(2)p.1228 - 12312008年06月-

Numerical simulation of critical current degradation of Nb3Sn strand in CIC conductor

Murakami H (Murakami, Haruyuki)1, Ishiyama A (Ishiyama, Atsushi)1, Ueda H (Ueda, Hiroshi)1, Koizumi N (Koizumi, Norikiyo)2, Okuno K (Okuno, Kiyoshi)2

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY18(2)p.1051 - 10542008年06月-

Recent development of an HTS power cable using YBCO tapes

Yagi M (Yagi, M.), Mukoyama S (Mukoyama, S.), Hirano H (Hirano, H.), Amemiya N (Amemiya, N.), Ishiyama A (Ishiyama, A.), Nagaya S (Nagaya, S.), Kashima N (Kashima, N.), Shiohara Y (Shiohara, Y.)

PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS463p.1154 - 11582007年10月-

Beamformerによる時間相関を持つ複数信号源推定

及川敬敏,木村壮志,斎藤優,葛西祐介,石山敦士,渡邊裕,葛西直子

日本生体磁気学会誌 特別号 第22回日本生体磁気学会大会論文集20(1)p.282 - 2832007年06月-

チホノフの正則化を用いたMEG信号源推定

斎藤優,及川敬敏,葛西祐介,石山敦士,渡邊裕,葛西直子

日本生体磁気学会誌 特別号 第22回日本生体磁気学会大会論文集20(1)p.278 - 2792007年06月-

脳内信号源推定における遺伝的アルゴリズムパラメータの最適化

佐々木貴志,嶋田裕介,安斉和久,及川敬敏,葛西祐介,斎藤優,石山敦士,渡邊裕,葛西直子

日本生体磁気学会誌 特別号 第22回日本生体磁気学会大会論文集20(1)p.274 - 2752007年06月-

ガムチューイングが短期記憶獲得時のθ波活動に及ぼす影響

堂脇可菜子,小野弓絵,石山敦士,小野塚実,

日本生体磁気学会誌 特別号 第22回日本生体磁気学会大会論文集20(1)p.258 - 2592007年06月-

MCGによる心疾患モデルマウスの経時的観察

葛西祐介,加古真祥,及川敬敏,斎藤優,小野弓絵,石山敦士,葛西直子,茅根一夫

日本生体磁気学会誌 特別号 第22回日本生体磁気学会大会論文集20(1)p.212 - 2132007年06月-

心磁図を用いた妊婦と胎児の心拍変動の関連評価

石山敦士,神山拡己,嶋田育代,及川敬敏,葛西祐介,斎藤優,中居賢司,福島明宗,伊藤学,葛西直子

日本生体磁気学会誌 特別号 第22回日本生体磁気学会大会論文集20(1)p.122 - 1232007年06月-

Assessment of cryogenic thermography system using commercial fluorescent paints on their applicability to visualization of normal-zone propagation in YBCO coated conductor

Ishiyama A (Ishiyama, Atsushi), Tsuchiya M (Tsuchiya, Motokazu), Ueda H (Ueda, Hiroshi), Shiohara Y (Shiohara, Yuh)

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY17(2)p.3765 - 37682007年06月-

Characteristics of Compressive strain and superconducting property in YBCO coated conductor

Takao T (Takao, Tomoaki), Koizuka S (Koizuka, Sho), Oi K (Oi, Kazuki), Ishiyama A (Ishiyama, Atsushi), Kato J (Kato, Junko), Machi T (Machi, Takato), Nakao K (Nakao, Koichi), Shiohara Y (Shiohara, Yu)

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY17(2)p.3517 - 35192007年06月-

Influence of bending and torsion strains on critical currents in YBCO coated conductors

Takao T (Takao, Tomoaki), Iwamura T (Iwamura, Tsutomu), Fukasawa Y (Fukasawa, Yuta), Minowa S (Minowa, Shigetoshi), Sato H (Sato, Hidenori), Asano T (Asano, Takashi), Ishiyama A (Ishiyama, Atsushi), Kato J (Kato, Junko), Machi T (Machi, Takato), Nakao K (Nakao, Koichi), Shiohara Y (Shiohara, Yu)

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY17(2)p.3513 - 35162007年06月-

Degradation of YBCO coated conductors due to over-current pulse

Ishiyama A (Ishiyama, Atsushi), Tanaka Y (Tanaka, Yasutake), Ueda H (Ueda, Hiroshi), Shiohara Y (Shiohara, Yuh), Machi T (Machi, Takato), Iijima Y (Iijima, Yasuhiro), Saitoh T (Saitoh, Takashi), Kashima N (Kashima, Naoji), Mori M (Mori, Masami), Watanabe T (Watanabe, Tomonori), Nagaya S (Nagaya, Shigeo)

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY17(2)p.3509 - 35122007年06月-

Asymmetrical normal zone propagation analysis considering Hall effect for large aluminum stabilized superconductor

Noguchi S (Noguchi, So), Kawawada N (Kawawada, Nobuki), Igarashi H (Igarashi, Hajime), Ishiyama A (Ishiyama, Atsushi), Yanagi N (Yanagi, Nagato), Imagawa S (Imagawa, Shinsaku)

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY17(2)p.2490 - 24932007年06月-

A criterion for determining stabilizer thickness of YBCO coated conductors based on coil protection

Ishiyama A (Ishiyama, Atsushi), Ueda H (Ueda, Hiroshi), Ando T (Ando, Taketoshi), Naka H (Naka, Hironori), Bamba S (Bamba, Sadanori), Shiohara Y (Shiohara, Yuh)

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY17(2)p.2430 - 24332007年06月-

Development of pipeline transporter system using pinning effect of high-temperature superconducting bulks

Ueda H (Ueda, Hiroshi), Tsuchiya M (Tsuchiya, Motokazu), Ishiyama A (Ishiyama, Atsushi)

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY17(2)p.2323 - 23262007年06月-

Transient stability characteristics of parallel-connected YBCO coated conductors for power transmission cables

Ishiyama A (Ishiyama, Atsushi), Iwata T (Iwata, Takuya), Ueda H (Ueda, Hiroshi), Mukoyama S (Mukoyama, Shinichi), Shiohara Y (Shiohara, Yuh)

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY17(2)p.1672 - 16752007年06月-

Numerical simulation of critical current and n-value in Nb3Sn strand subjected to bending strain

Murakami H (Murakami, Haruyuki), Ishiyama A (Ishiyama, Atsushi), Ueda H (Ueda, Hiroshi), Koizumi N (Koizumi, Norikiyo), Okuno K (Okuno, Kiyoshi)

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY17(2)p.1394 - 13972007年06月-

3D electromagnetic analysis of levitating transporter using bulk superconductor

Ueda H (Ueda, Hiroshi), Azumaya S (Azumaya, Satoshi), Tsuchiya S (Tsuchiya, Satoshi), Ishiyama A (Ishiyama, Atsushi)

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY16(2)p.1092 - 10952007年06月-

YBCO線材の繰り返しひずみ特性

田中洋輔, 安東武利, 番場貞徳, 植田浩史, 石山敦士, 山田穣, 塩原融

平成19年電気学会全国大会2007年03月-

YBCO超電導線材の過電流パルス通電による特性劣化—曲げ歪の影響—

石山敦士, 王旭東, 田中康武, 植田浩史, 鹿島直二, 森匡見, 渡部智則, 長屋重夫, 町敬人, 塩原融

平成19年電気学会全国大会2007年03月-

数値シミュレーションによるNb3Sn素線の曲げ歪印加時における超電導特性の評価

村上陽之, 植田浩史, 我妻洸, 石山敦士, 小泉徳潔, 奥野清

平成19年電気学会全国大会2007年03月-

超電導送電ケーブルを想定した並列接続YBCO超電導線材の過渡的安定性評価

石山敦士, 西尾幸恭, 王旭東, 岩田拓也, 植田浩史, 向山晋一, 塩原融

平成19年電気学会全国大会2007年03月-

YBCO 超電導線材の過電流パルス通電による特性劣化

石山敦士, 田中康武, 植田浩史, 飯島康裕, 斎藤隆, 鹿島直二, 森 匡見, 渡部智則, 長屋重夫, 加藤丈晴, 町敬人, 塩原融

電気学会超電導応用電力機器研究会2007年01月-

蛍光剤を用いた2次元温度分布観測システムを用いたYBCO 線材の常電導転移・伝播の可視化

石山敦士, 土屋元計, 植田浩史, 加藤英幸, 奈良広一, 塩原融

電気学会超電導応用電力機器研究会2007年01月-

数値シミュレーションによるNb3SN 素線の曲げ歪印加時における超電導特性の評価

村上陽之, 植田浩史, 石山敦士, 小泉徳潔, 奥野清

電気学会超電導応用電力機器研究会2007年01月-

超電導送電ケーブルを想定した並列接続YBCO 超電導線材の過渡的安定性評価

石山敦士, 岩田拓也, 王旭東, 植田浩史, 向山晋一, 塩原融

電気学会超電導応用電力機器研究会2007年01月-

冷凍機伝導冷却YBCO 超電導コイルの熱特性評価実験・解析

石山敦士, 安東武利, 番場貞徳, 植田浩史, 富士広, 飯島康裕, 斉藤隆, 塩原融

電気学会超電導応用電力機器研究会2007年01月-

YBCO線材の繰り返しひずみ特性

番場貞徳, 安東武利, 植田浩史, 我妻洸, 石山敦士, 飯島康裕, 斎藤隆

2006年度秋季低温工学・超電導学会2006年11月-

YBCO超電導線材の過電流パルス通電による特性劣化

石山敦士, 田中康武, 植田浩史, 飯島康裕, 斎藤隆, 鹿島直二, 森 匡見, 渡部智則, 長屋重夫, 加藤丈晴, 町敬人, 塩原融

2006年度秋季低温工学・超電導学会2006年11月-

YBCO超電導線材を用いた超電導ケーブル導体の過電流特性解析

植田浩史, 岩田拓也, 王旭東, 石山敦士, 向山晋一, 塩原融

2006年度秋季低温工学・超電導学会2006年11月-

球体バルク超電導体を用いたアクティブ磁気浮上の位置制御(シミュレーション)

石垣善弘, 菅兼治, 植田浩史, 我妻洸, 石山敦士

2006年度秋季低温工学・超電導学会2006年11月-

球体バルク超電導体を用いたアクティブ磁気浮上の位置制御(実験)

菅兼治, 石垣善弘, 植田浩史, 我妻洸, 石山敦士

2006年度秋季低温工学・超電導学会2006年11月-

蛍光剤を用いた2次元温度分布観測システムによるYBCO線材の常電導転移・伝播の可視化

石山敦士, 土屋元計, 植田浩史, 塩原融, 加藤英幸, 奈良広一

2006年度秋季低温工学・超電導学会2006年11月-

数値シミュレーションによるNb3SN素線の曲げ歪印加時における超電導特性の評価

村上陽之, 植田浩史, 石山敦士,小泉徳潔,奥野清

2006年度秋季低温工学・超電導学会2006年11月-

超電導送電ケーブルを想定した並列接続YBCO超電導線材の過渡的安定性評価(1,実験 )

石山敦士, 王旭東, 岩田拓也, 植田浩史, 向山晋一, 塩原融

2006年度秋季低温工学・超電導学会2006年11月-

超電導送電ケーブルを想定した並列接続YBCO超電導線材の過渡的安定性評価(2,シミュレーション)

石山敦士, 岩田拓也, 王旭東, 植田浩史, 向山晋一, 塩原融

2006年度秋季低温工学・超電導学会2006年11月-

冷凍機伝導冷却YBCO超電導コイルの熱特性評価解析

石山敦士, 安東武利, 番場貞徳, 植田浩史, 富士広, 斉藤隆, 塩原融

2006年度秋季低温工学・超電導学会2006年11月-

A Stability Criterion for design of YBCO Coated Conductors and Coils based on Quench Protection

A. Ishiyama, H. Ueda, T. Ando, H. Naka, S. Banba, Y. Shiohara

Applied Superconductivity Conference 20062006年09月-

Assessment of Cryogenic Thermography System using Commercial Fluorescent paints on their Applicability to Visualization of Normal-zone Propagation in YBCO coated Conductor

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

Applied Superconductivity Conference 20062006年09月-

Degradation of YBCO coated conductors due to over-current pulse

A. Ishiyama, Y. Tanaka, T. Ando, T. Iwata, H. Ueda, Y. Shiohara, T. Saitoh

Applied Superconductivity Conference 20062006年09月-

Development of Pipeline Transporter System using Pinning Effect of High-Temperature Superconducting Bulks

H. Ueda, M. Tsuchiya, A. Ishiyama

Applied Superconductivity Conference 20062006年09月-

Numerical Simulation of Critical Current and n-value in Nb3Sn strand Subjected to Bending Strain

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

Applied Superconductivity Conference 20062006年09月-

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

A. Ishiyama, T. Iwata, H. Ueda, S. Mukoyama, Y. Shiohara

Applied Superconductivity Conference 20062006年09月-

母親の心拍変動と胎児の心拍変動との関連解析 −音楽による影響−

神山拡己,葛西祐介,白井健吾,木村壮志,加古真祥,及川敬敏,斎藤優,石山敦士,中居賢司,福島明宗,伊藤学,葛西直子

日本生体磁気学会誌 特別号 第21回日本生体磁気学会大会論文集19(1)p.250 - 2512006年06月-

心疾患モデルマウスの心磁計測

加古真祥,中村祐,木村壮志,葛西祐介,及川敬敏,斎藤優,神山拡己,小野弓絵,石山敦士,葛西直子

日本生体磁気学会誌 特別号 第21回日本生体磁気学会大会論文集19(1)p.246 - 2472006年06月-

先見情報を用いないBeamformer法による複数信号源推定

木村壮志,加古真祥,神山拡己,及川敬敏,葛西祐介,斎藤優,石山敦士,葛西直子

日本生体磁気学会誌 特別号 第21回日本生体磁気学会大会論文集19(1)p.222 - 2232006年06月-

マグネトメータを用いたMEG信号源推定 −その2 グラジオメータとの併用による推定精度の向上−

斎藤優,及川敬敏,葛西祐介,木村壮志,加古真祥,神山拡己,石山敦士,葛西直子,渡邊裕,河合毅師

日本生体磁気学会誌 特別号 第21回日本生体磁気学会大会論文集19(1)p.220 - 2212006年06月-

マグネトメータを用いたMEG信号源推定 −その1 シミュレーションによる推定精度の検証−

及川敬敏,斎藤優,葛西祐介,木村壮志,加古真祥,神山拡己,石山敦士,葛西直子

日本生体磁気学会誌 特別号 第21回日本生体磁気学会大会論文集19(1)p.218 - 2192006年06月-

小動物用SQUID磁気計測システム

石山敦士

日本生体磁気学会誌 特別号 第21回日本生体磁気学会大会論文集19(1)p.16 - 172006年06月-

Numerical simulation of the critical current and n-value in Nb3Sn strand subjected to bending strain

Hirohashi M (Hirohashi, Masayuki), Murakami H (Murakami, Haruyuki), Ishiyama A (Ishiyama, Atsushi), Ueda H (Ueda, Hiroshi), Koizumi N (Koizumi, Norikiyo), Okuno K (Okuno, Kiyoshi)

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY16(2)p.1721 - 17242006年06月-

Transient stability analysis taking into account Hall effect for large aluminum stabilized superconductor

Kawawada N (Kawawada, Nobuki), Noguchi S (Noguchi, So), Igarashi H (Igarashi, Hajime), Ishiyama A (Ishiyama, Atsushi), Yanagi N (Yanagi, Nagato), Imagawa S (Imagawa, Shinsaku)

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY16(2)p.1717 - 17202006年06月-

3D Electromagnetic Analysis of Levitating Transporter Using Bulk Superconductor

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

IEEE Trans. on Appl. Supercond.16(2)p.1092 - 10952006年06月-

Nb3Sn 素線の曲げ歪印加時における超電導特性の数値解析・評価

村上陽之, 植田浩史, 我妻洸, 石山敦士, 小泉徳潔, 奥野清

電気学会超電導応用電力機器研究会2006年06月-

YBCO 線材の過電流パルス通電による特性劣化について

石山敦士, 王旭東,植田浩史, 飯島康裕, 斎藤隆, 鹿島直二, 森匡見, 渡部智則, 長屋重夫, 町敬人, 塩原融

電気学会超電導応用電力機器研究会2006年06月-

コイル保護に基づくYBCO 線材の安定化層厚の決定法

石山敦士, 番場貞徳, 安東武利, 植田浩史, 我妻洸

電気学会超電導応用電力機器研究会2006年06月-

バルク超電導体のピン止め力を用いたパイプライン搬送装置の基礎特性実験

石垣善弘, 植田浩史, 我妻洸, 石山敦士

電気学会超電導応用電力機器研究会2006年06月-

球体バルク超電導体を用いたアクティブ磁気浮上の位置制御

菅兼治, 植田浩史, 我妻洸, 石山敦士

電気学会超電導応用電力機器研究会2006年06月-

Nb3Sn素線の曲げ歪印加時における超電導特性の数値解析・評価

村上陽之, 植田浩史, 石山敦士, 小泉徳潔, 奥野清

2006年度春季低温工学・超電導学会2006年05月-

YBCO線材の過電流パルス通電による特性劣化について(1) − 安定化層の厚みの効果 −

石山敦士, 王旭東, 植田浩史, 飯島康裕, 斎藤隆, 塩原融

2006年度春季低温工学・超電導学会2006年05月-

YBCO線材の過電流パルス通電による特性劣化について(2) − 線材の長さ・運転温度の影響 −

番場貞徳, 植田浩史, 石山敦士, 飯島康裕, 斎藤隆, 鹿島直二, 森匡見, 渡部智則, 長屋重夫, 町敬人, 塩原融

2006年度春季低温工学・超電導学会2006年05月-

コイル保護に基づくYBCO線材の安定化層厚の決定法(1) − 決定法の提案 −

石山敦士, 安東武利, 植田浩史, 塩原融

2006年度春季低温工学・超電導学会2006年05月-

コイル保護に基づくYBCO線材の安定化層厚の決定法(2) − 適用例 −

石山敦士, 安東武利, 植田浩史, 塩原融

2006年度春季低温工学・超電導学会2006年05月-

バルク超電導体のピン止め力を用いたパイプライン搬送装置の基礎特性実験

石垣善弘, 土屋元計, 植田浩史, 我妻洸, 石山敦士

2006年度春季低温工学・超電導学会2006年05月-

球状バルク超電導体を用いたアクティブ磁気浮上の位置制御

植田浩史, 菅兼治, 我妻洸, 石山敦士

2006年度春季低温工学・超電導学会2006年05月-

着磁したバルク超電導体を二次側走行子に適用したリニア同期アクチュエータの特性評価

菅兼治, 植田浩史, 石山敦士

2006年度春季低温工学・超電導学会2006年05月-

YBCO線材の過電流パルス通電試験

岩田拓也,安東武利,田中康武,村上陽之,牛久裕輔,仲寛徳,植田浩史,石山敦士,塩原融

第73回2005年度秋季 低温工学・超電導学会 公演概要集73p.932005年11月-

数値解析に基づくYBCO超電導コイルの熱的特性評価

安東武利,岩田拓也,田中康武,村上陽之,牛久裕輔,仲寛徳,植田浩史,石山敦士,塩原融

第73回2005年度秋季 低温工学・超電導学会 公演概要集73p.762005年11月-

ホール効果を考慮したLHD超伝導体の過度安定性評価シミュレーション

川田伸樹,野口聡,五十嵐一,石山敦士,柳長門,今川信作

第73回2005年度秋季 低温工学・超電導学会 公演概要集73p.332005年11月-

曲げ歪印加時のNB3Sn素線の臨界電流およびn値の数値解析・評価

村上陽之,広橋雅元,植田浩史,石山敦士,小泉徳潔,奥野清

第73回2005年度秋季 低温工学・超電導学会 公演概要集73p.2782005年11月-

YBCO線材用基板ハステロイの面内熱伝導度とアニール効果

千葉純一,亀掛川−佐々木尚子,石山敦士,山田穣,和泉輝郎,塩原融

第73回2005年度秋季 低温工学・超電導学会 公演概要集73p.2432005年11月-

引張り及び圧縮応力によるYBCOテープの特性変化

小飯塚翔,深澤雄太,大井一樹,高尾智明,石山敦士,斉藤隆,塩原融

第73回2005年度秋季 低温工学・超電導学会 公演概要集73p.2392005年11月-

高速多重極法を用いた超伝導体を含む3次元電磁界解析

植田浩史,石山敦士

第73回2005年度秋季 低温工学・超電導学会 公演概要集73p.2242005年11月-

YBCO線材の過電流パルス通電時の特性劣化について

田中康武,安東武利,岩田拓也,村上陽之,牛久裕輔,仲寛徳,植田浩史,石山敦士,塩原融

第73回2005年度秋季 低温工学・超電導学会 公演概要集73p.1512005年11月-

高温超電導コイルのクエンチ保護に関する考察

仲寛徳,牛久裕輔,安東武利,岩田拓也,田中康武,村上陽之,植田浩史,石山敦士,塩原融

第73回2005年度秋季 低温工学・超電導学会 公演概要集73p.1202005年11月-

バルク超伝導体のピン止め力を用いた搬送装置の基礎特性実験

土屋元計,土屋賢史,東谷智史,植田浩史,石山敦士

第73回2005年度秋季 低温工学・超電導学会 公演概要集73p.1062005年11月-

不整脈モデルマウスの心磁図計測による非侵襲的心機能評価

石山敦士,白井賢吾,中村祐,加古真祥,木村壮志,小野弓絵,葛西直子

日本生体磁気学会誌 特別号 第20回日本生体磁気学会論文集18(2)p.78 - 792005年07月-

時間相関成分の除去を行うBeamformer法による聴覚および視覚反応の複合信号推定

木村壮志,j加古真祥,中村祐,白井健吾,神山拡己,石山敦士,葛西直子,岩木直,小野弓絵,外池光雄

日本生体磁気学会誌 特別号 第20回日本生体磁気学会論文集18(2)p.258 - 2592005年07月-

MEGを用いた視聴覚間相互作用の検討

加古真祥,木村壮志,神山拡己,小野弓絵,石山敦士,葛西直子,外池光雄

日本生体磁気学会誌 特別号 第20回日本生体磁気学会論文集18(2)p.256 - 2572005年07月-

母・胎児の自律神経系活動の評価

白井健吾,中村祐,小野弓絵,中居賢司,福島明宗,伊藤学,石山敦士,葛西直子

日本生体磁気学会誌 特別号 第20回日本生体磁気学会論文集18(2)p.202 - 2032005年07月-

加齢に伴うマウス心筋活動強化変化の定量的評価

中村祐,神山拡己,白井健吾,加古真祥,木村壮志,小野弓絵,石山敦士,葛西直子

日本生体磁気学会誌 特別号 第20回日本生体磁気学会論文集18(2)p.194 - 1952005年07月-

バルク超電導体のピン止め力を用いた搬送装置の基礎特性評価

土屋元計,土屋賢史,東谷智史,植田浩史,石山敦士

第72回2005年度春季 低温工学・超電導学会 公演概要集72p.2672005年06月-

Y系線材の過電流パルス通電特性評価(実験)

岩田拓也,安東武利,田中康武,村上陽之,牛久裕輔,仲寛徳,植田浩史,石山敦士,塩原融,斉藤隆

第72回2005年度春季 低温工学・超電導学会 公演概要集72p.182005年06月-

Y系線材の過電流パルス通電特性評価(数値解析)

安東武利,岩田拓也,田中康武,村上陽之,牛久裕輔,仲寛徳,植田浩史,石山敦士,塩原融

第72回2005年度春季 低温工学・超電導学会 公演概要集72p.1692005年06月-

高分解能u-SQUIDを用いた不整脈モデルマウスの心磁図計測

石山敦士,小野弓絵,葛西直子

第72回2005年度春季 低温工学・超電導学会 公演概要集72p.1662005年06月-

空間・時間的相関に基づくMEGデータの信号源数推定

星野大介,小野弓絵,石山敦士,葛西直子,外池光雄

日本生体磁気学会誌17(2)p.31 - 412005年03月-

YBCOテープにおける臨界電流の耐圧縮および引張応用力実験

小飯塚翔,梅川健治,深澤雄太,高尾智明(上智大学),石山敦士(早稲田大学),斎藤隆(フジクラ),塩原融(超電導工学研究所)

2005年03月-

Y系線材の過電流パルス通電特性評価(実験)

田中康武,安東武利,岩田拓也,村上陽之,牛久裕輔,中 寛徳,森崎徹,柳井正浩,植田浩史,石山敦士(早稲田大学),塩原融,鬼頭豊(ISTEC)

2005年03月-

Y系線材の過電流パルス通電特性評価(数値解析)

田中康武,安東武利,岩田拓也,村上陽之,牛久裕輔,中 寛徳,森崎徹,柳井正浩,植田浩史,石山敦士(早稲田大学),塩原融,鬼頭豊(ISTEC)

2005年03月-

バルク超伝導体を用いた浮上搬送置の設計・特性評価

土屋元計,土屋賢史,東谷智史,久遠勇哉,植田浩史,石山敦士

2005年03月-

Magnetocardiogram on wild-type and arrhythmia model mice

Y. Ono, K. Shirai, T. Nakamura, A. Ishiyama, N. Kasai

Technical report of IEICE SCE2004-41(2005-2) (Selected paper of 2005 Japan-Taiwan Symposium on Superconductive Electronics)104(655)p.23 - 262005年02月-

Y 系線材の常電導転移・伝播特性評価

石山敦士, 柳井正浩, 牛久裕輔, 仲 寛徳, 植田浩史, 飯島康裕, 斉藤 隆, 塩原 融

電気学会超電導応用電力機器・リニアドライブ合同研究会2005年01月-

高温超電導SMESの技術調査

一瀬中,秋田調,石山敦士,高祖聖一,辰田昌功

低温工学40(5)p.150 - 1582005年-

YBCO線材の常電導転移・伝播特性評価

石山敦士, 柳井正浩, 植田浩史, 飯島康裕, 斉藤隆, 塩原融

低温工学39(11)p.560 - 5662004年11月-

着磁されたバルク超電導体の交流磁界印加特性

植田浩史, 森崎徹, 石山敦士

電気学会論文誌B124-B(11)p.1358 - 13642004年11月-

3次元電磁界解析によるバルク超電導体を用いた浮上搬送装置の試設計と浮上特性評価

植田浩史, 東谷智史, 土屋賢史, 久藤勇哉, 石山敦士

2004年度秋季低温工学・超電導学会2004年11月-

YBCO超電導線材の常電導転移特性評価(実験)

仲寛徳, 牛久 裕輔, 森崎徹, 柳井正浩, 植田浩史, 石山敦士, 塩原融, 飯島康裕, 柿本一臣, 斉藤隆

2004年度秋季低温工学・超電導学会2004年11月-

YBCO超電導線材の常電導転移特性評価(数値解析)

牛久裕輔, 仲寛徳, 森崎徹, 柳井正浩, 植田浩史, 石山敦士, 塩原融, 飯島康裕, 柿本一臣, 斉藤隆

2004年度秋季低温工学・超電導学会2004年11月-

バルク超電導体を用いた磁気浮上搬送装置-製作と特性評価-」

土屋賢史, 東谷智史, 久藤勇哉, 植田浩史, 石山敦士

2004年度秋季低温工学・超電導学会2004年11月-

バルク超電導体を用いた浮上搬送装置の開発ー浮上特性へのバックヨークの影響ー

東谷智史, 土屋賢史, 久藤勇也, 植田浩史, 石山敦士

2004年度秋季低温工学・超電導学会2004年11月-

複数のコイルとバルク超電導体を用いたアクティブ磁気浮上位置制御の改善

伊藤祐介, 田代靖貴, 植田浩史, 石山敦士

2004年度秋季低温工学・超電導学会2004年11月-

Lift and restoring force characteristics of a levitating X-Y transporter using high-temperature superconducting bulks”,

M. Iwamoto, H. Ueda, A. Ishiyama

Superconductor Science and Technology17(8)p.1042 - 10452004年10月-

バルク超電導体を用いた磁気浮上装置のための基礎特性評価と3次元電磁界解析

植田浩史, 岩本真実, 久藤勇哉, 石山敦士

電気学会論文誌B124-B(10)p.1200 - 18002004年10月-

Lift and  Restoring Force Characteristics Evaluation of Levitating X-Y Transporter Using HTS BulksApplied

Y. Kudou, H. Ueda, A. Ishiyama

Superconductivity Conference 20042004年10月-

Normal Transition and Propagation Characteristics of YBCO Tape

A. Ishiyama, M. Yanai, T. Morisaki, H. Ueda, Y. Shiohara, T. Izumi

Applied Superconductivity Conference2004年10月-

Position Control of Active Magnetic Levitation using YBCO Bulk and Multiple Electromagnets

Y. Tashiro, H. Ueda, A. Ishiyama

Applied Superconductivity Conference2004年10月-

Operational Characteristics of Linear Synchronous Actuator with Field-Cooled HTS Bulk Secondary

A. Sato, H. Ueda, A. Ishiyama

Applied Superconductivity Conference2004年09月-

Development of biomagnetic measurement system for mice with high spatial resolution

Yumie Ono, Atsushi Ishiyama, Naoko Kasai, Kazuo Chinone

Applied Physics LettersVolume 85, Issue 2(85)p.332 - 3342004年07月-

電磁界解析によるバルク超電導体を用いた浮上搬送装置の特性評価

植田浩史, 東谷智史, 土屋賢史, 久藤勇哉, 石山敦士

電気学会超電導応用電力機器研究会2004年06月-

Preliminary experiments of a tubular linear actuator in the vertical direction using YBCO bulk”, Superconductor Science and Technology, vol. 17, issue 5, pp. S176-S179, May 2004

A. Sugawara, H. Ueda, A. Ishiyama

Superconductor Science and Technology17(5)p.176 - 1792004年05月-

Dynamic characteristics and finite element analysis of magnetic levitation system using YBCO bulk superconductor

H. Ueda, A. Ishiyama

Superconductor Science and Technology17(5)p.170 - 1752004年05月-

3次元電磁界解析によるバルク超電導体を用いた浮上搬送装置の浮上特性評価

植田浩史, 東谷智史, 土屋賢史, 久藤勇哉, 石山敦士

2004年度春季低温工学・超電導学会2004年05月-

YBCO線材の常電導転移・伝播特性評価

牛久裕輔, 仲寛徳, 柳井正浩, 森崎徹, 植田浩史, 石山敦士, 塩原融

2004年度春季低温工学・超電導学会2004年05月-

バルク超電導体を用いた浮上搬送装置-磁極配置による浮上特性への影響-

東谷智史, 土屋賢史, 久藤勇哉, 植田浩史, 石山敦士

2004年度春季低温工学・超電導学会2004年05月-

着磁したバルク超電導体を二次側走行子に用いたリニア同期アクチュエータの試作・特性評価

柴田貴広, 広橋雅元, 佐藤飛鳥, 植田浩史, 石山敦士

2004年度春季低温工学・超電導学会2004年05月-

複数のコイルとバルク超電導体を用いたアクティブ磁気浮上位置制御装置

伊藤祐介, 田代靖貴, 植田浩史, 石山敦士

2004年度春季低温工学・超電導学会2004年04月-

Bayesian Classification of Myocardial Excitation Abnormality Using Magnetocardiogram Maps for Mass Screening (BIOMAG2004)

Y. Ono, A. Ishiyama, N. Kasai, S. Yamada, K. On, S. Watanabe, I. Yamaguchi, T. Miyashita, K. Tsukada

Neurology and Clinical Neurophysiology (Online journal)2004年-

着磁されたバルク超伝導体の交流磁界印加特性の評価

森崎徹, 伊藤学, 植田浩史, 石山敦士

第69回2003年度秋季 低温工学・超電導学会 講演概要集p.2192003年12月-

着磁したバルク超伝導体を二次側走行子とするリニア同期アクチュエータの試作と基礎実験

佐藤飛鳥, 井比敏男, 植田浩史, 石山敦士

第69回2003年度秋季 低温工学・超電導学会 講演概要集p.2152003年12月-

バルク超伝導体を用いた浮上搬送装置−永久磁石の磁極配置の浮上特性への影響−

久遠勇哉, 岩本真美, 植田浩史, 石山敦士

第69回2003年度秋季 低温工学・超電導学会 講演概要集p.2142003年12月-

バルク超伝導体を用いた鉛直方向リニア・アクチュエータ

田代靖貴, 菅原淳史, 植田浩史, 石山敦士

第69回2003年度秋季 低温工学・超電導学会 講演概要集p.2132003年12月-

Y系超電導テープ線材の常伝導転移特性

柳井正浩, 曽我部義高, 植田浩史, 石山敦士, 塩原融

第69回2003年度秋季 低温工学・超電導学会 講演概要集p.1002003年12月-

Trapped Field Characteristic of HTS Bulk in AC External Magnetic Field

IEEE Trans. on Applied Superconductivity13(2)p.2283 - 22862003年06月-

Trial production and experiment of linear synchronous actuator with field-cooled HTS bulk secondary

IEEE Trans. on Applied Superconductivity13(2)p.2251 - 22542003年06月-

Characteristics of levitating X-Y transporter using HTS bulks

IEEE Trans. on Applied Superconductivity13(2)p.2161 - 21642003年06月-

A new type of active-Maglev system using YBCO bulk and multiple electromagnets

IEEE Trans. on Applied Superconductivity13(2)p.2157 - 21602003年06月-

An optimization method for design of SMES coils using YBCO tape

IEEE Trans. on Applied Superconductivity13(2)p.1856 - 18592003年06月-

心磁図マップのウェーブレット近似を用いた心筋梗塞診断

小野弓絵, 石山敦士, 葛西直子, 塚田啓二, 宮下豪, 温環, 渡辺重行, 宮内卓, 山口巌

日本生体磁気学会 特別号 第18回日本生体磁気学会論文集16(1)p.68 - 692003年05月-

脳内信号源推定におけるGA・SA組合せ法とL1ノルム最小化の比較~その[2]実験データへの適用〜

栗山鉱明, 星野大介, 小林宏史, 小野弓絵, 石山敦士, 葛西直子, 外池光雄

日本生体磁気学会 特別号 第18回日本生体磁気学会論文集16(1)p.260 - 2612003年05月-

脳内信号源推定におけるGA・SA組み合わせ法とLIノルム最小化法の比較〜その[1]シミュレーションによる推定誤差と計算時間の比較〜

星野大介, 栗山鉱明, 小林宏史, 石山敦士, 葛西直子,外池光雄

日本生体磁気学会 特別号 第18回日本生体磁気学会論文集16(1)p.258 - 2592003年05月-

視覚・聴覚同時刺激における聴覚N100m潜時の短縮

小野弓絵, 足立信夫, 小林宏史, 栗山鉱明, 星野大介, 石山敦士, 葛西直子, 外池光雄

日本生体磁気学会 特別号 第18回日本生体磁気学会論文集16(1)p.210 - 2112003年05月-

SQUIDを用いた非破壊検査技術- 冷凍機を用いSQUID非破壊検査システム-

石山敦士,廿日出好, 葛西直子, 高島浩, 坂巻充彦, 丸野善生

第68回2003年度春季低温工学・超電導学会 講演概要集p.862003年05月-

有限要素法による着磁されたバルク超伝導体の交流磁界印加特性解析

植田浩史, 伊藤学, 森崎徹, 石山敦士

第68回2003年度春季低温工学・超電導学会 講演概要集p.2572003年05月-

SQUIDを用いた非破壊検査技術

石山敦士, 廿日出好, 葛西直子, 高島浩, 坂巻充彦, 丸野善生,

第68回2003年度春季低温工学・超電導学会 講演概要集p.2222003年05月-

系統安定化用SMESを想定したHTSコイルの最適化設計

石山敦士, 野口聡, 秋田調, 笠原奉文, 辰田昌功, 高祖聖一

第68回2003年度春季低温工学・超電導学会p.2082003年05月-

着磁されたバルク超伝導体の交流磁界印加特性

森崎徹, 伊藤学, 植田浩史, 石山敦士

第68回2003年度春季低温工学・超電導学会 講演概要集p.1212003年05月-

複数のコイルとバルク超伝導体による鉛直方向搬送実験

田代靖貴, 菅原淳史, 植田浩史, 石山敦士

第68回2003年度春季低温工学・超電導学会 講演概要集p.1202003年05月-

バルク超伝導体を用いた浮上搬送装置−2つのバルク体を対向させたときの浮上特性実験−

植田浩史, 岩本真美, 久遠勇哉, 石山敦士

第68回2003年度春季低温工学・超電導学会p.1192003年05月-

着磁したバルク超伝導体を二次側走行子とするリニア同期アクチュエータの試作・実験

佐藤飛鳥, 井比敏男, 植田浩史, 石山敦士

第68回2003年度春季低温工学・超電導学会 講演概要集p.1172003年05月-

系統安定化用SMESを想定した冷凍機伝導冷却小型HTSコイルの熱的挙動について

曽我部義高, 五十峯幸治, 石山敦士, 秋田調, 笠原奉文, 高祖聖一, 安部秀行, 田崎賢司

第67回2002年度秋季 低温工学・超電導学会 公演概要集p.562002年10月-

着磁したバルク超伝導体を二次側走行子とするリニア同期アクチュエータの試作と基礎実験

井比敏男, 高橋淳, 植田浩史, 石山敦士

第67回2002年度秋季 低温工学・超電導学会 公演概要集p.2192002年10月-

複数のコイルとバルク超伝導体による鉛直方向搬送実験

菅原敦史, 鴨志田亮太, 植田浩史, 石山敦士

第67回2002年度秋季 低温工学・超電導学会 公演概要集p.2162002年10月-

バルク超伝導体を用いた浮上搬送装置−2つのバルク超伝導体を対向させたときの浮上特性−

岩本真美, 赤松猛, 植田浩史, 石山敦士

第67回2002年度秋季 低温工学・超電導学会 公演概要集p.2142002年10月-

着磁されたバルク超伝導体の交流磁界印加特性解析

伊藤学, 植田浩史, 石山敦士

第67回2002年度秋季 低温工学・超電導学会 公演概要集2002年10月-

着磁したバルク超伝導体を二次側走行子とするリニア同期アクチュエータの試作・実験

井比敏男, 高橋淳, 植田浩史, 石山敦士

第66回2002年度春季 低温工学・超電導学会 公演概要集p.202002年05月-

系統安定化用SMESを想定した冷凍機伝導冷却小型HTSコイルの運転特性評価

曽我部義高, 五十峯幸治, 石山敦士, 秋田調, 笠原奉文, 高祖聖一, 田崎賢司

第66回2002年度春季 低温工学・超電導学会 公演概要集p.1862002年05月-

バルク超伝導体を用いた自由に方向転換可能な浮上搬送装置の特性評価

岩本真美, 赤松猛, 植田浩史, 石山敦士

第66回2002年度春季 低温工学・超電導学会 公演概要集p.1772002年05月-

着磁されたバルク超伝導体の交流磁界印加特性

伊藤学, 植田浩史, 石山敦士

第66回2002年度春季 低温工学・超電導学会 公演概要集p.1752002年05月-

複数の電磁石とバルク超伝導体による鉛直方向アクティヴ連続磁気浮上

菅原敦史, 鴨志田亮太, 植田浩史, 石山敦士

第66回2002年度春季 低温工学・超電導学会 公演概要集p.1732002年05月-

Detection of internal cracks and delamination in carbon-fiber-reinforced plastics using SQUID-NDI system

Physica C267p.372 - 3762002年03月-

A basic study on algorithm for automatic diagnosis by MCG

Physica C2002年03月-

遺伝的アルゴリズムとシミュレーテッド・アニーリングを組み合わせた脳内複数信号源推定法

電気学会基礎材料共通部門誌A分冊2002年01月-

空間周波数解析を用いた心筋の興奮伝播解析—心磁界シミュレーションによる検討—

電気学会基礎材料共通部門誌A分冊2001年12月-

多装蓄熱シールドを用いたクライオスタットの特性評価

赤松猛, 石山敦士, 高橋政彦, 栗山透

第65回2001年度秋季 低温工学・超電導学会 公演概要集p.2082001年11月-

バルク超伝導体を用いた自由に方向転換可能な浮上搬送装置

赤松猛, 寺西康幸, 植田浩史, 石山敦士

第65回2001年度秋季 低温工学・超電導学会 公演概要集p.202001年11月-

系統安定化用SMESを想定した冷凍機伝導冷却小型HTSコイルの運転特性評価

五十嵐幸治, 北平尚丈, 石山敦士, 秋田調, 笠原奉文, 田附浩之, 田崎賢司

第65回2001年度秋季 低温工学・超電導学会 公演概要集p.1932001年11月-

着磁されたバルク超伝導体の交流磁界印加特性

植田浩史, 清水英仁, 石山敦士

第65回2001年度秋季 低温工学・超電導学会 公演概要集p.1122001年11月-

着磁したバルク超伝導体を二次側走行子とするリニア同期アクチュエータの試作・実験

高橋淳, 定方俊吾, 植田浩史, 石山敦士

第65回2001年度秋季 低温工学・超電導学会 公演概要集p.1052001年11月-

系統安定化用SMESを想定した小型冷凍機伝導冷却HTSコイルの運転特性評価

五十峯幸治, 北平尚丈, 浅井弘樹, 石山敦士, 秋田調, 笠原奉文, 坂口秀治

第64回2001年度春季 低温工学・超電導学会 公演概要集p.982001年05月-

複数の電磁石とバルク超電導による連続アクティヴ磁気浮上

鴨志田亮太, 高橋淳, 林浩幹, 植田浩史, 石山敦士

第64回2001年度春季 低温工学・超電導学会 公演概要集p.782001年05月-

バルク超伝導体を二次側走行子とするリニアアクチュエータの試作・実験

高橋淳, 定方俊吾, 植田浩史, 石山敦士

第64回2001年度春季 低温工学・超電導学会 公演概要集p.762001年05月-

磁気遮へい型超電導限流器の試設計と有限要素法による動作特性評価

門裕之, 市川路晴, 植田浩史, 石山敦士

第64回2001年度春季 低温工学・超電導学会 公演概要集p.1882001年05月-

バルク超伝導体を用いた自由に方向転換可能な浮上搬送装置−振動特性評価−

赤松猛, 寺西康幸, 植田浩史, 石山敦士

第64回2001年度春季 低温工学・超電導学会 公演概要集p.1112001年05月-

Nondestructive Detection of Delamination in Carbon-Fiber-Reinforced Plastics Using Superconducting Quantum Interference Device.

A. Ishiyama, Y.Hatsukade, N.Kasai 40(6B):L606-L608

Japanease Journal of Applied physics40(6B)p.L606 - L6082001年03月-

Trial production and experiments of linear actuator with bulk HTS secondary

A. Ishiyama, R.Muramatsu,S.Sadakata,M.Tsuda

IEEE Trans. on Applied Superconductivity/IEEE11(2)p.1976 - 19792001年03月-

A Stability criterion for cryocooler-cooled HTS coils

A. Ishiyama and others

IEEE Trans. on Applied Superconductivity/IEEE11(2)2001年03月-

Thermal and magnetic characteristics of bulk superconductor and performance analysis of magnetic shielding type of superconducting falt current limiter

A. Ishiyama, H.Ueda, H.Kado, M.Ichikawa

IEEE Trans. on Applied Superconductivity/IEEE11(1)p.2402 - 24052001年03月-

Improvement of superconducting cylindrical linear induction motor

A. Ishiyama, T.Kikuma 11(1):2331-2334,Part2

IEEE Trans. on Applied Superconductivity/IEEE11(1)p.2331 - 23342001年03月-

An optimal design method for superconducting magnets using HTS Tape

A. Ishiyama, S.Noguchi,M.Yamashita,H.Yamashita

IEEE Trans. on Applied Superconductivity/IEEE11(1)p.2308 - 23112001年03月-

Trapped field characteristics of YBCO bulk in time-varying external magnetic field

A. Ishiyama. T.Ohyama,H.Shimizu,M.Tsuda

IEEE Trans. on Applied Superconductivity/IEEE11(1)p.1988 - 19912001年03月-

Characteristics of lift and restoring force in HTS bulk

A. Ishiyama, Y.Sanagawa,H.Ueda,M.Tsuda

IEEE Trans. on Applied Superconductivity/IEEE11(1)p.1797 - 18002001年03月-

Development of NDE method using SQUID for reconstruction of defect shape

A. Ishiyama, Y.Hatsukade, N.Kasai, H.Takashima, .Kawai,F. Kojima

IEEE Trans. on Applied Superconductivity/IEEE11(1)p.1311 - 13142001年03月-

複数の電磁石を用いたバルク超電導体の連続アクティブ磁気浮上

石山敦士、津田理、真川康弘、林浩幹、植田浩史 Vol.36,NO.2,PP.68-78

低温工学/低温工学会36(2)p.67 - 682001年02月-

A New Type of Active-maglev System Usong YBCO Bulk and Multiple Electromagnets

Cryogenic Engineering, Journal of the Cryogenic Society of Japan36(2)p.68 - 782001年-

A Stability Criterion for Cryocooler-Cooled HTS Coils

IEEE Transaction on Applied Superconductivity11(1)p.1832 - 18352001年-

Characteristics of Lift and Restoring Force in HTS Bulk

IEEE Trans. on Applied Superconductivity11(1)p.1797 - 18002001年-

An Optimal Design Method for High-temperature Superconducting Magnets

2001年-

Development of NDE Method using SQUID for Reconstruction of Defect Shape

2001年-

Improvement of Superconducting Cylindrical Linear Induction Motor

2001年-

Thermal and Magnetic Characteristics of Bulk Superconductor and Performance Analysis of Magnetic Shielding Type of Superconducting Falt Current Limiter

2001年-

Trapped Field Characteristics of YBCO Bulk in Time-varying External Magnetic field

2001年-

Trial Production and Experiments of Linear Actuator with Bulk HTS Secondary

2001年-

Characteristics of Bulk Superconducting Cylinder for Magnetic Shielding Type Superconducting Cyrrent Limiter

S.Noguchi,H.Ueda,A. Ishiyama

Proc. of the 4th European Conf. on Applied Superconductivity4p.997 - 10002000年09月-

Normal-zone Propagation Properties in BSCCO Silver Sheathed Tapes

A. Ishiyama, S.Shimizu

Proc. of the 4th European Conf. on Applied Superconductivity4p.547 - 5502000年09月-

Detection of Internal Defects using HTS-SQUID for Non-destructive Evaluation

A. Ishiyama, Y.Hatsukade, N.Kasai, F.Kojima, H.Takashima

Proc. of the 4th European Conf. on Applied Superconductivity4p.513 - 5162000年09月-

Construction and Experiments of a Superconducting Cylindrical Linear Induction Motor with AC Superconducting Primary Windings

A. Ishiyama, M.Tomita, T.Kikuma, M.Tsuda

Proc. of the 4th European Conf. on Applied Superconductivity4p.1079 - 10822000年09月-

冷凍機伝導冷却高温超電導コイルの安定性評価基準について

平成12年電気学会全国大会講演論文集5-2282000年03月-

超電導垂直円筒型短一次リニア誘導モータにおけるクエンチ検出保護制御回路

平成12年電気学会全国大会講演論文集5-2272000年03月-

超電導垂直円筒型短一次リニア誘導モータの励磁電流の最適化

平成12年電気学会全国大会講演論文集5-2262000年03月-

バルク超電導体を二次走行子とするリニアアクチュエータの試作・実験

平成12年電気学会全国大会講演論文集5-2242000年03月-

複数の電磁石とバルク超電導体による連続磁気浮上

平成12年電気学会全国大会講演論文集5-2222000年03月-

着磁されたバルク超電導体の変動磁界中における電磁気的振舞について

平成12年電気学会全国大会講演論文集5-2002000年03月-

YBCO超電導薄膜テープ線材のクエンチ特性

平成12年電気学会全国大会講演論文集5-1952000年03月-

N1m活動源の周波数依存性 その(1)—聴性誘発脳磁界のS/Nへの刺激間隔・加算平均回数の影響

平成12年電気学会全国大会講演論文集2-1482000年03月-

N1m活動源の周波数依存性 その(2)—GA/SA組み合わせ法による信号源推定

平成12年電気学会全国大会講演論文集2-1482000年03月-

Electromagnetic Behavior on High-temperature Superconducting Bulk YBCO Exposed to Time-varying Magnetic Field

A. Ishiyama, M.Tsuda, T.Susa, T.Ohyama, S.Kohayashi, S.Haseyama

IEEE Trans. on Applied Superconductivity/IEEE10(1)p.894 - 8972000年03月-

超電導垂直円筒型短一次リニア誘導モータの特性改善

電気学会超電導応用電力機器・リアドライブ合同研究会資料ASC-00-352000年01月-

バルク超電導体を二次走行子とするリニア・アクチュエータの試作・実験

電気学会超電導応用電力機器・リアドライブ合同研究会資料ASC-00-342000年01月-

バルク超電導体の浮上・案内力特性の評価・浮上搬送装置への応用

電気学会超電導応用電力機器・リアドライブ合同研究会資料ASC-00-332000年01月-

着磁されたバルク超電導体の変動磁界中における電磁気的特性

電気学会超電導応用電力機器・リアドライブ合同研究会資料ASC-00-322000年01月-

バルク超電導体特性の温度・磁界依存性と磁気遮へい型限流器の動作特性評価

電気学会超電導応用電力機器・リアドライブ合同研究会資料ASC-00-202000年01月-

YBCO薄膜テープ線材のクエンチ特性

電気学会超電導応用電力機器・リアドライブ合同研究会資料ASC-00-22000年01月-

冷凍機伝導冷却高温超電導コイルの安定性評価基準について

電気学会超電導応用電力機器・リアドライブ合同研究会資料ASC-00-172000年01月-

バルク超電導体特性の温度・磁界依存性と磁気遮へい型超電導限流器の動作特性解析

門裕之、市川路晴、植田浩史、石山敦士

低温工学/低温工学会35(5)p.246 - 2542000年01月-

Thermal and Magnetic Characteristics of Bulk Superconductor and Performance Analysis of Magnetic Shielding Type of Superconducting Falt Current Limiter

Cryogenic Engineering, Journal of the Cryogenic Society of Japan35(5)p.246 - 2542000年-

Electromagnetic behavior on high-temperature superconducting bulk YBCO exposed to time-varying magnetic fueld

IEEE Trans. on Applied Superconductivity10(1)p.894 - 8972000年-

Fundamental Characteristic Estimation Based on Finite Element Method for Magnetic Shielding Type Superconducting Fault Current Limiter

Trans. IEE of Japan10(1)p.894 - 8972000年-

Development of Linear Actuator with YBCO Bulk Secondary

A. Ishiyama, M.Tsuda,T.Koike,R.Muramatsu,S.Kohayashi,S.Haseyama

Advances in SuperconductivityⅩⅡp.818 - 8202000年-

Transport characteristics in YBCO thin film superconductors

A. Ishiyama, S.B.Kim,Y.Takahashi,K.Matsumoto,T.Takagi,T.Machi,N.Koshizuka,I.Hirabayashi

Advances in SuperconductivityⅩⅡp.619 - 6212000年-

Development of Linear Actuator with YBCO Bulk Secondary

Advances in Superconductivity(]G0007[)/,818-8202000年-

Transport characteristics in YBCO thin film superconductors

Advances in Superconductivity(]G0007[)/,619-6212000年-

radial成分をもつ信号源推定のためのMEG/EEG併用法

石山敦士、上杉直登、大能祐介、葛西直子

電気学会論文誌(A部門誌)119-A(12)p.1451 - 14581999年12月-

Basic Study for Non-Destructobe Detection of Flaws in CFRP using HTS-SQUID Gradiometer

Proc. of Japan-Romania Joint Seninar on Applied Electromagnetics and Mechanical Systemsp.234 - 2391999年12月-

Development of kA-class Gas-cooled HTS Current Lead for Superconducting Fault Current Limiter

A.Ishiyama, S.Odaka,S.B.Kim,Y.Sato,S.Honjo,Y.Iwata,S.Shingo

IEEE Trans. on Applied Superconductivity/IEEE9(2)p.491 - 4941999年11月-

超電導バルク体を二次走行子とするリニアモータの試作・実験

第61回低温工学・超電導学会講演概要集61p.331999年11月-

超電導円筒型短一次リニア誘導モータの特性改善

第61回低温工学・超電導学会講演概要集61p.321999年11月-

冷凍機伝導冷却高温超電導コイルの安定性評価基準について

第61回低温工学・超電導学会講演概要集61p.2171999年11月-

有限要素法による磁気遮へい型超電導限流器の動作特性評価

第61回低温工学・超電導学会講演概要集61p.2151999年11月-

YBCO薄膜テープ線材のクエンチ特性

第61回低温工学・超電導学会講演概要集61p.1051999年11月-

磁気浮上用超電導バルク体の浮上・案内力特性実験

第61回低温工学・超電導学会講演概要集61p.1031999年11月-

交流磁場中における超電導バルク体の振舞いに関する基礎実験

第61回低温工学・超電導学会講演概要集61p.1021999年11月-

有限要素法による磁気遮へい型超電導限流器の基礎特性評価

電気学会論文誌119B(11)p.1201 - 12091999年11月-

有限要素法による磁気遮へい型超電導限流器の基礎特性評価

石山敦士、中津川潤之介、野口聡、門裕之、市川路晴

電気学会論文誌(B部門誌)/電気学会119-B(11)p.1201 - 12091999年11月-

内外の超電導電力機器の開発状況—SMESの開発状況

1999年度第2回低温工学会超電導応用研究会シンポジウム1999年10月-

脳磁界解析のためのウェーブレット変換による信号処理

電気学会マグネティクス研究会資料MAG-99-1331999年08月-

空間周波数を用いたMCG解析法の開発

電気学会マグネティクス研究会資料MAG-99-1041999年08月-

リニア誘導モータの解析

電気学会産業応用部門大会講演論文集 (1)1p.35 - 381999年08月-

超電導垂直円筒型短一次リニア誘導モータの試作実験と特性解析

電気学会超電導応用電力機器・回転機合同研究会資料ASC-99-401999年07月-

Bi系超電導テープ線材の常電導伝播特性評価

電気学会超電導応用電力機器・回転機合同研究会資料ASC-99-271999年07月-

Multi-source Localization with MEG evoked by Odorant Stimulation

A. Ishiyama, M.Okumura, N.Uesugi, Y.Hatsukade, T.Nagano, M.Tonnoike, M.Yamaguchi, N.Kasai

Proc. of the 11th Int. Conf. On Biomagnetism11p.603 - 6061999年07月-

Localization of Dipole with Radial Component using a MEG/EEG Hybrud Method

A. Ishiyama, N.Kasai, Y.Ohno,N. Uesugi, Y.Hatsukade, M.Tonoike

Proc. of the 11th Int. Conf. On Biomagnetism11p.240 - 2431999年07月-

Estimation of Ventricular Excitation by MCG with Restrictios of Solution Area

A. Ishiyama, N.Uesugi,H.Sugaya,S.Osozawa,N.Kasai

Proc. of the 11th Int. Conf. On Biomagnetism11p.1074 - 10771999年07月-

Transient Stability of Large Aluminum Stabilized Superconductors

IEEE Trans. on Applied Superconductivity9(2)p.624 - 6271999年06月-

Transient Stability of Large Aluminum Stabilized Superconductors

A. Ishiyama, S.Noguchi, A.Ishiyama, T.Satow

IEEE Trans. on Applied Superconductivity/IEEE9(2)p.624 - 6271999年06月-

Recent Technical Trends of Superconducting Magnets in Japan (Part 2)

IEEE Trans. on Applied Superconductivity9(2)p.600 - 6031999年06月-

Recent Technical Trends of Superconducting Magnets in Japan (Part 2)

A. Ishiyama, O.Tsukamoto, S.Torii, T.Takao, N.Amemiya, S.Fukui, T.Hoshino, A.Ishiyama, A.Ninomiya, H.Yamaguchi, T.Satow

IEEE Trans. on Applied Superconductivity/IEEE9(2)p.600 - 6031999年06月-

Development of kA-class Gas-cooled HTS Current Lead for Superconducting Fault Current Limiter

A. Ishiyama, S.Odaka,S.B.Kim,Y.Sato,S.Honjo,Y.Iwata,S.Shingo

IEEE Trans. on Applied Superconductivity9(2)p.491 - 4941999年06月-

Design and Construction of a Superconducting Cylindrical Linear Induction Motor with AC Superconducting Primary Windings

A. Ishiyama, K.Hayashi

IEEE Trans. on Applied Superconductivity9(2)p.1217 - 12201999年06月-

Design and Construction of a Superconducting Cylindrical Linear Induction Motor with AC Superconducting Primary Windings

A. Ishiyama, K.Hayashi

IEEE Trans. on Applied Superconductivity/IEEE9(2)p.1217 - 12201999年06月-

Magnetic Characteristics of a High-Tc Superconducting Cylinder for Magnetic Shielding Type Superconducting Fault Current Limiter

A. Ishiyama, K.Hayashi

IEEE Trans. on Applied Superconductivity9(2)p.1217 - 12201999年06月-

Stability Test Results on the Aluminum Stabilized Superconductor for the Helical Coils LHD

N.Yanagi,T.Satow,T.Mito, S.Noguchi, A.Ishiyama

IEEE Trans. on Applied Superconductivity/IEEE9(2)p.1113 - 11161999年06月-

Quench Propagation Properties in HTS Pancake Coil

A. Ishiyama, S.Shimizu,S.B.Kim

IEEE Trans. on Applied Superconductivity/IEEE9(2)p.1077 - 10801999年06月-

有限要素法による磁気遮へい型超電導限流器の基礎特性評価

石山敦士、中津川潤之介、野口聡、門裕之、市川路晴

第60回低温工学・超電導学会講演概要集119-B(11)p.1201 - 12091999年06月-

非破壊検査用HTS-SQUIDを用いた周波数変化による内部傷形状の検出

第60回低温工学・超電導学会講演概要集p.891999年06月-

超電導垂直円筒型リニア誘導モータの試作・実験

第60回低温工学・超電導学会講演概要集p.2541999年06月-

早大理工学部におけるSMES実験(教育用学生実験)

第60回低温工学・超電導学会講演概要集p.241999年06月-

Bi系超電導線材の常電導伝播特性評価

第60回低温工学・超電導学会講演概要集p.2321999年06月-

Recent Technical Trends of Superconducting Magnets in Japan (Part 1)

A. Ishiyama, O.Tsukamoto, S.Torii, T.Takao, N.Amemiya, S.Fukui, T.Hoshino, A.Ishiyama, A.Ninomiya, H.Yamaguchi, T.Satow 9(2): 547-552,Part1

IEEE Trans. on Applied Superconductivity/IEEE9(2)p.547 - 5521999年05月-

ウェーブレット変換を用いた信号処理

日本生体磁気学会誌12(1)p.96 - 971999年05月-

ウェーブレット変換を用いた信号処理

石山敦士,奥村雅行、廿日出好、野村公比呂、高田薫、葛西直子、外池光雄、岩木直

日本生体磁気学会誌/日本生体磁気学会12(1)p.96 - 971999年05月-

空間周波数を用いた心磁界解析法の開発

石山敦士、野村公比呂、上杉直登、奥村雅行、廿日出好、高田薫、葛西直子、塚田啓二、宮下豪

日本生体磁気学会誌/日本生体磁気学会12(1)p.182 - 1831999年05月-

GAとSAの組み合わせ法の聴覚MEGへの適用

石山敦士、高田薫、野村公比呂、水野恭滋、上杉直登、奥村雅行、廿日出好、葛西直子、外池光雄、岩木直

日本生体磁気学会誌12(1)p.100 - 1011999年05月-

生体磁気計測における信号源推定法

マグネティックス研究会資料/電気学会MAG-99-31999年03月-

超電導垂直円筒型短一次リニア誘導モータの試作・実験

超電導応用電力機器・リニアドライブ合同研究会資料/電気学会ASC-99-19/LD-99-191999年01月-

有限要素法による磁気遮蔽型超電導限流器の基礎特性評価

超電導応用電力機器・リニアドライブ合同研究会資料/電気学会ASC-99-18/LD-99-181999年01月-

酸化物超電導コイルの常電導伝播特性

超電導応用電力機器・リニアドライブ合同研究会資料/電気学会ASC-99-13/LD-99-131999年01月-

Transient Stability of Large Aluminum Stabilized Superconductors

IEEE Trans. on Applied Superconductivity9(2)p.624 - 6271999年-

Recent Technical Trends of Superconducting Magnets in Japan(Part 2)

IEEE Trans. on Applied Superconductivity9(2)p.600 - 6031999年-

Recent Technical Trends of Superconducting Magnets in Japan(Part 1)

IEEE Trans. on Applied Superconductivity9(2)p.547 - 5501999年-

Development of kA-class Gas-cooled HTS Current Lead for Superconducting Fault Current Limiter

IEEE Trans. on Applied Superconductivity9(2)p.491 - 4941999年-

Magnetic Characteristics of a High-Tc Superconducting Cylinder for Magnetic Shielding Type Superconducting Fault Current Limiter

IEEE Trans. on Applied Superconductivity9(2)p.491 - 4941999年-

Design and Construction of a Superconducting Cylindrical Linear Induction Motor with AC Superconducting Primary Windings

IEEE Trans. on Applied Superconductivity9(2)p.1217 - 12201999年-

Stability Test Results on the Aluminum Stabilized Superconductor for the Helical Coils LHD

IEEE Trans. on Applied Superconductivity9(2)p.1113 - 11161999年-

Quench Propagation Properties in HTS Pancake Coil

IEEE Trans. on Applied Superconductivity9(2)p.1077 - 10801999年-

有限要素法による磁気遮へい型超電導限流器の基礎特性評価

電気学会論文誌 B119-B(11)p.1201 - 12091999年-

Estimation of Source with radial Component Using Hybrid MEG/EEG Method

Trans. IEE of Japan119-A(12)p.1451 - 14581999年-

radial成分をもつ信号源推定のためのMEG(脳磁図)・EEG(脳波)併用法

電気学会論文誌A119-A(12)p.1451 - 14581999年-

磁気遮蔽型限流器用超電導バルク円筒体の磁気遮蔽特性

静止器研究会資料/電気学会SA-98-301998年12月-

Normal-zone propagation properties in Bi-2223/Ag superconducting multifilament tapes

A.Ishiyama, S.B.Kim,H.Okada

Cryogenics/ELSEVIER38(8)p.823 - 8311998年11月-

超電導酸化物バルク体のリニアモータへの応用

第59回低温工学・超電導学会講演概要集/低温工学会E2-11998年10月-

酸化物超電導コイルの常電導伝播特性

第59回低温工学・超電導学会講演概要集/低温工学会E1-151998年10月-

磁気遮蔽型限流器用超電導バルク円筒体の磁気遮蔽特性

第59回低温工学・超電導学会講演概要集/低温工学会A2-91998年10月-

YBCO薄膜線材の常電導伝播特性

第59回低温工学・超電導学会講演概要集/低温工学会A2-31998年10月-

超電導垂直円筒型リニア誘導モータの試作

第59回低温工学・超電導学会講演概要集/低温工学会A1-41998年10月-

感度解析を取り入れた高磁界・高均一超電導マグネットの最適化設計

石山敦士,野口聡

電気学会論文誌/電気学会118-B(10)p.1103 - 11091998年10月-

感度解析を取り入れた高磁界・高均一超電導マグネットの最適化設計

石山敦士、野口聡

電気学会論文誌/電気学会118-B(10)p.1103 - 11091998年10月-

Experimental and analytical estimation for transient stability in AC multi-strand superconducting cabes

A. Ishiyama, M.Sasaki,T.Susa,S.Noguchi,S.B.Kim,Mtsuda,H.Yumura,K.Ohmatsu,K.Sato

Proceedings of the 17th International Cryogenic Engineering Conference/ICEC17p.365 - 3681998年07月-

Characteristics of Gas-cooled HTS current leads for superconducting fault current limiters

A. Ishiyama, S.B.Kim, S.Odaka, S.Noguchi, S.Honjo, Y.Iwata, S.Shingo

Proceedings of the 15th International Conference on Magnet Technology/Science Press15p.563 - 5661998年07月-

An optimal design method for magnetic shields of MRI superconducting magnets by using equivqlent magnetization current method

S.Noguchi A. Ishiyama

Proceedings of the 15th International Conference on Magnet Technology/Science Press15p.1414 - 14171998年07月-

An optimal design method for magnetic shields of MRI superconducting magnets by using equivqlent magnetization current method

A. Ishiyama, S.Noguchi PP.1414-1417

Proceedings of the 15th International Conference on Magnet Technology/Science Press15p.1414 - 14171998年07月-

Characteristics of Gas-cooled HTS current leads for superconducting fault current limiters

A. Ishiyama, M.Sasaki,K.Ohgitani,S.B.Kim,M.Tsuda

Proceedings of the 15th International Conference on Magnet Technology/Science Press15p.1120 - 11231998年07月-

Effect of Cu-sheath on transient stability of AC multi-strand superconducting cables

A. Ishiyama, M.Sasaki,K.Ohgitani,S.B.Kim,M.Tsuda

Proceedings of the 15th International Conference on Magnet Technology/Science Press15p.1120 - 11231998年07月-

超電導垂直円筒型短一次リニア誘導モータの試作

超電導応用電力機器・回転機合同研究会資料/電気学会ASC-98-47/RM-98-611998年06月-

交流用超電導撚線導体の過渡安定性評価

第58回低温工学・超電導学会講演概要集/低温工学会A3-71998年05月-

ラザフォード型超電導導体の素線間接触電気抵抗の測定

第58回低温工学・超電導学会講演概要集/低温工学会A3-41998年05月-

超電導垂直円筒型リニア誘導モータの設計と製作

第58回低温工学・超電導学会講演概要集/低温工学会A2-61998年05月-

Multi-source localization by Genetic Algorithm using MEG

A. ishiyama, T.Nagano,Y.Ohno,N.Uesugi 34 (5) : 2976-2979Part1

IEEE Transactions on MAGNETICS/IEEE34(5)p.2976 - 29791998年05月-

Multi-source localization by Genetic Algorithm using MEG

T.Nagano,Y.Ohno,N.Uesugi A. Ishiyama,

IEEE Transactions on MAGNETICS/IEEE34(5)p.2976 - 29791998年05月-

Transient stability of AC multi-strand superconducting cables

A. Ishiyama, M.Sasaki,T.Susa,S.B.Kim,M.Tsuda,H.Yumura,K.Ohmatsu,K.Sato

Physica C/ELSEVIER310(1月4日)p.345 - 3501998年05月-

Transient stability of AC multi-strand superconducting cables

A. Ishiyama, M.Sasaki,T.Susa,S.B.Kim,M.Tsuda,H.Yumura,K.Ohmatsu,K.Sato

Physica C/ELSEVIER310(1月4日)p.345 - 3501998年05月-

MEG/EEG併用法によるradial成分をもつ信号源の推定(正中神経刺激データへの適用)

日本生体磁気学会誌/日本生体磁気学会11;11998年05月-

ファントムを用いたMEG実験による複数信号源推定精度の検証

日本生体磁気学会誌/日本生体磁気学会11;11998年05月-

ファントムを用いたMEG実験による複数信号源推定精度の検証

日本生体磁気学会誌/日本生体磁気学会11;11998年05月-

嗅覚MEGの複数信号源推定

日本生体磁気学会誌/日本生体磁気学会11;11998年05月-

磁気遮蔽型限流器用超電導バルク円筒体の磁気遮蔽特性

平成10年電気学会全国大会/電気学会12161998年03月-

超電導垂直円筒型短一次リニア誘導モータの三相不平衡の解析

平成10年電気学会全国大会/電気学会12061998年03月-

酸化物超電導コイルの線間方向常電導伝播特性

平成10年電気学会全国大会/電気学会11941998年03月-

交流用より線導体の過渡安定性評価試験

平成10年電気学会全国大会/電気学会11791998年03月-

LTS、HTS超電導応用技術の研究開発動向

電気学会第664号1998年01月-

感度解析を考慮した高磁界・高均一超電導マグネットの最適化設計

電気学会超電導応用電力機器・リニアドライブ合同研究会/電気学会ASC-98-18,LD-98-181998年01月-

交流用超電導より線導体の過渡安定性評価

電気学会超電導応用電力機器・リニアドライブ合同研究会/電気学会ASC-98-14,LD-98-141998年01月-

An Optimal Design Method for High Field and Highly Homogeneous Superconducting Magnets

Trans. IEE of Japan118-B(10)p.1103 - 11091998年-

「感度解析を取り入れた高磁界・高均一超電導マグネットの最適化設計」

電気学会論文誌B118-B(10)p.1103 - 11091998年-

磁気遮蔽型限流器用超電導バルク円筒体の磁気遮蔽特性

第57回低温工学・超電導学会講演概要集/低温工学会E1-251997年11月-

交流用超電導より線導体の常殿堂転移特性

第57回低温工学・超電導学会講演概要集/低温工学会B3-71997年11月-

感度解析を考慮した高磁界・高均一超電導マグネットの最適化設計

第57回低温工学・超電導学会講演概要集/低温工学会B3-141997年11月-

脳磁界計測のための信号源推定法の開発

第12回日本応用磁気学会学術講演会p.1261997年10月-

交流用高温超電導電流リードの熱侵入量形状依存性評価

電気学会超電導応用電力機器・回転機合同研究会ASC-97-42,RM-97-551997年07月-

ラザフォード型超電導導体における素線間接触抵抗の高感度測定

電気学会超電導応用電力機器・回転機合同研究会ASC-97-41,RM-97-541997年07月-

交流用超電導撚線導体の過渡安定性に対する銅シースの効力

電気学会超電導応用電力機器・回転機合同研究会ASC-97-30,RM-97-431997年07月-

超電導垂直円筒型リニア誘導モータの設計と特性解析

電気学会超電導応用電力機器・回転機合同研究会ASC-97-21,RM-97-341997年07月-

Recent Technical Trends of Superconducting Magnets in Japan (Part 1)

A. Ishiyama, O.Tsukamoto, S.Torii, T.Takao, N.Amemiya, S.Fukui, T.Hoshino, A.Ishiyama, A.Ninomiya, H.Yamaguchi, T.Satow

IEEE Trans. on Applied Superconductivity/IEEE9(2)p.547 - 5521997年07月-

Measurements of Cross Contact Resistance in Rutherford Cables

Proc. of International Cryogenic Engineering Conference1997年07月-

Numerical Experiments for Transient stability in Dry-winding Superconducting Magnets

Proc. of International Cryogenic Engineering Conference1997年07月-

Design and Characteristics Analysis of Superconducting Tubular linear Induction Motor

A. Ishiyama, J.P.Xu,S.Iino 7 (2) :660-663 Part1

IEEE Transactions on Applied Superconductivity/IEEE7(2)p.660 - 6631997年06月-

An Optimal Design Method for High Field Superconducting Magnets with Ferromagutir shields

A. ishiyama, S.Noguchi

IEEE Transactions on Applied Superconductivity/IEEE7(2)p.439 - 4421997年06月-

Improvement of Transient Stability of Transient Stability of Non-insulated AC-Multi-strand Superconducting Cables

A.ishiyama, T.Yoshino,M.Tsuda

IEEE Transactions on Applied Superconductivity/IEEE7(2)p.231 - 2341997年06月-

Transient Stability Analysis in Bi-2223/Ag Superconducting Tapes

A. Ishiyama, SB.Kim

IEEE Transactions on Applied Superconductivity/IEEE7(2)p.203 - 2061997年06月-

An Optimal Design Method for High Field Superconducting Magnets with Ferromagutir shields

IEEE Transactions on Applied Superconductivity7(2)1997年06月-

Design and Characteristics Analysis of Superconducting Tubular linear Induction Motor

IEEE Transactions on Applied Superconductivity7(2)1997年06月-

Improvement of Transient Stability of Transient Stability of Non-insulated AC-Multi-strand Superconducting Cables

IEEE Transactions on Applied Superconductivity7(2)1997年06月-

Transient Stability Analysis in Bi-2223/Ag Superconducting Tapes

IEEE Transactions on Applied Superconductivity7(2)1997年06月-

MEG/EEG併用法の逆問題解析の試み

第12回日本生体磁気学会大会SI-41997年05月-

ラザフォード型超電導導体の素線間接触電気抵抗の測定

第56回低温工学超伝導学会講演概要集/低温工学会E3-281997年05月-

超電導トランスを用いたラザフォード型超電導導体の安定性評価のための基礎実験

第56回低温工学超伝導学会講演概要集/低温工学会E3-271997年05月-

超電導垂直円筒型リニア誘導モータの特性(1)一次電流の最適化

第56回低温工学超伝導学会講演概要集/低温工学会E3-191997年05月-

超電導垂直円筒型リニア誘導モータの特性(1)三相不平衡電流

第56回低温工学超伝導学会講演概要集/低温工学会E3-181997年05月-

交流用高温超電導電流リードの熱侵入量形状依存性評価(2)複数本化の効果

第56回低温工学超伝導学会講演概要集/低温工学会E2-231997年05月-

交流用高温超電導電流リードの熱侵入量形状依存性評価(1)戻りガスによる冷却の様子

第56回低温工学超伝導学会講演概要集/低温工学会E2-221997年05月-

交流用超電導より線の三次元有限要素法を用いた過渡安定性解析

第56回低温工学超伝導学会講演概要集/低温工学会C3-91997年05月-

MCGによる心筋興奮波面推定

日本生体磁気学会誌/日本生体磁気学会10(1)1997年05月-

MEG/EEG併用法を用いた信号源推定

日本生体磁気学会誌/日本生体磁気学会10(1)1997年05月-

遺伝的アルゴリズムによる複数信号源推定

日本生体磁気学会誌/日本生体磁気学会10(1)1997年05月-

遺伝的アルゴリズムによる複数信号源推定

電気学会マグネティックス研究会MAG-97-531997年04月-

MEG/EEG併用法による信号源推定(2)radial dipole成文を含む信号源推定

電気学会マグネティックス研究会MAG-97-521997年04月-

MEG/EEG併用法による信号源推定(1)2層半球ファントム内の電流ダイポールの位置推定

電気学会マグネティックス研究会MAG-97-511997年04月-

MEG/EEG併用法による脳信号推定

平成9年電気学会全国大会講演論文集/電気学会4941997年03月-

交流用超電導より線の三次元有限要素法を用いた過渡安定性解析

平成9年電気学会全国大会講演論文集/電気学会13291997年03月-

ラザフォード型超電導導体の素線間の接触電気抵抗の測定

平成9年電気学会全国大会講演論文集/電気学会13281997年03月-

等価磁化電流法を用いたMRI超電導マグネット用磁気シールドの形状最適化設計

平成9年電気学会全国大会講演論文集/電気学会13001997年03月-

超電導垂直円筒型一次リニア誘導モータの設計と特性解析

平成9年電気学会全国大会講演論文集/電気学会12921997年03月-

高温超電導コイルの常電導伝播シミュレーション

日本シミュレーション学会計算電気・電子工学シンポジウム/日本シミュレーション学会I-91996年12月-

磁気シールド付き高均一超電導マグネットの最適化設計

日本シミュレーション学会計算電気・電子工学シンポジウム/日本シミュレーション学会I-21996年12月-

超電導垂直円筒型リニア誘導モータの設計と特性解析

電気学会回転機研究会資料/電気学会RM-96-881996年10月-

逐次解領域選択法による心筋興奮波面推定

電気学会マグネティックス研究会資料/電気学会MAG-96-1481996年10月-

超電導垂直円筒状リニア誘導モータの設計と特性解析

第55回低温工学・超電導学会講演概要集/低温工学会E3-271996年10月-

交流用超電導より線の過渡安定性

第55回低温工学・超電導学会講演概要集/低温工学会B3-71996年10月-

高温超電導コイル内の常電導伝播シミュレーション(その1)

第55回低温工学・超電導学会講演概要集/低温工学会B3-51996年10月-

Experiment and Numerical Analysis of Normal Zone Propagation Properties in Ag Sheathed Bi-2223 Superconducting Tapes

A. Ishiyama, S.Kim,Y.Ueno,H.Okada,S.Nomura,H.Maeda

IEEE Transactions on Magnetics/IEEE32(4)p.2882 - 28251996年07月-

Stability of non-insulated A.C. multi-strand superconducting cables

A. ishiyama, M.Matsui,32(4):2854-2857,Part1

IEEE Transactions on Magnetics/IEEE32(4)p.2854 - 28571996年07月-

An optimal design method for higthly homogeneous and high-field superconducting magnets

A. Ishiyama, S.Noguchi

32(4)p.2655 - 26581996年07月-

An optimal design method for higthly homogeneous and high-field superconducting magnets

IEEE Transactions on Magnetics/IEEE32(4)1996年07月-

Experiment and Numerical Analysis of Normal Zone Propagation Properties in Ag Sheathed Bi-2223 Superconducting Tapes

IEEE Transactions on Magnetics/IEEE32(4)1996年07月-

Stability of non-insulated A.C. multi-strand superconducting cables

IEEE Transactions on Magnetics/IEEE32(4)1996年07月-

ビスマス系銀シース多芯テープ超伝導線材の常電導伝播特性

低温工学/低温工学協会31(7)1996年07月-

交流用超電導より線導体の過渡安定性

電気学会超電導応用電力機器研究会資料/電気学会ASC-96-25 RM-96-351996年06月-

Measurements of cross contact resistance in rutherford cables

Proceeding of the sixteenth ICEC and ICMC/Elsevier1996年06月-

Numerical experiments for transient stability in dry-winding superconducting magnets

Proceeding of the sixteenth ICEC and ICMC/Elsevier1996年06月-

遺伝的アルゴリズムによる信号源推定

日本生体磁気学会誌/日本生体磁気学会9(1)1996年05月-

逐次解領域選択法による心筋興奮波面推定

日本生体磁気学会誌/日本生体磁気学会9(1)1996年05月-

MEG/EEG併用法による脳内信号源推定−頭部を模擬した2層半球ファントムによるMEG実験と解析

平成8年電気学会全国大会講演論文集/電気学会4901996年03月-

てんかん患者のMEGデータの雑音除去

平成8年電気学会全国大会講演論文集/電気学会4891996年03月-

素線絶縁のないNbTi/CuNi3本より線導体におけるクエンチ特性について

平成8年電気学会全国大会講演論文集/電気学会12271996年03月-

アルミニウム安定化大容量超電導導体の過渡安定性解析

平成8年電気学会全国大会講演論文集/電気学会12261996年03月-

金属系および酸化物超電導導体の線間方向常電導伝播特性

平成8年電気学会全国大会講演論文集/電気学会12211996年03月-

逆問題解法の現状

電気学会マグネティクス研究会資料/電気学会MAG-96-351996年02月-

Bi系(2223相)銀シーステープ超電導導体の常電導伝播特性

電気学会論文誌B/電気学会116(2)1996年02月-

脳磁界計測における体積電流の影響−半球ファントムモデルによる実験と解析

電気学会論文誌C/電気学会116(2)1996年02月-

非含侵超電導マグネットの過渡安定性に関する数値実験

電気学会超電導応用電力機器,電線・ケーブル共同研究会資料/電気学会ASC-96-12, EC-96-121996年01月-

An Optimal Design Method for High Field Superconducting Magnets

Physica B/Elsevier Science B.V.216;3・41996年01月-

等価磁化電流法による磁気シールド付き超電導マグネットの最適化設計

第16回計算電気・電子工学シンポジウム/日本シミュレーション学会II-71995年12月-

脳磁界計測における体積電流の影響−てんかんの焦点位置推定

第16回計算電気・電子工学シンポジウム/日本シミュレーション学会I-71995年12月-

MCG解析のための逐次解領域選択法

電気学会マグネティクス研究会資料/電気学会MAG-95-1451995年11月-

素線絶縁のない交流用超電導より線導体のクエンチ特性

第54回低温工学・超電導学会講演概要集/低温工学会D2-31995年11月-

交流高温超電導電流リードの熱侵入量測定II

第54回低温工学・超電導学会講演概要集/低温工学会C3-31995年11月-

磁気シールド付き高磁界超電導マグネットの最適化設計

第54回低温工学・超電導学会講演概要集/低温工学会C1-111995年11月-

Bi系銀シース多芯テープ導体の線間方向常電導伝播特性

第54回低温工学・超電導学会講演概要集/低温工学会B2-111995年11月-

磁気シールド付き高磁界超電導マグネットの最適化設計

電気学会超電導応用電力機器研究会資料/電気学会ASC-95-441995年10月-

Bi-2223銀シーステープ超電導導体の常電導伝播特性

電気学会超電導応用電力機器研究会資料/電気学会ASC-95-401995年10月-

境界要素法によるてんかんの焦点位置推定について

電気学会マグネティクス研究会資料/電気学会MAG-95-641995年06月-

高磁界・高均一超電導マグネットの最適化

第14回シミュレーション・テクノロジー・コンファレンス/日本シミュレーション学会I-51995年06月-

Influence of Current Distribution on Quench Process in Non-insulated AC Multi-strand Superconducting Cables

IEEE Trans. on MAGNETICS/IEEE5(2)1995年06月-

ラザフォード型超電導導体の素線間接触電気抵抗の測定

第53回低温工学・超電導学会講演概要集/低温工学会C3-111995年05月-

素線絶縁のない交流用超電導撚線ケーブル導体のクエンチ実験

第53回低温工学・超電導学会講演概要集/低温工学会B3-91995年05月-

密巻超電導巻線の過渡安定性に関する数値実験

第53回低温工学・超電導学会講演概要集/低温工学会B3-41995年05月-

Bi系銀シース多芯テープ導体の常電導伝播速度の測定

第53回低温工学・超電導学会講演概要集/低温工学会B3-231995年05月-

超電導マグネット設計への遺伝的アルゴリズムの適用

第53回低温工学・超電導学会講演概要集/低温工学会B3-21995年05月-

素線絶縁の無い超電導撚線ケーブル導体のクエンチ特性に対する母材の影響実験

第53回低温工学・超電導学会講演概要集/低温工学会B3-101995年05月-

マルチセクション超電導マグネットのための最適化設計手法の比較

第53回低温工学・超電導学会講演概要集/低温工学会B3-11995年05月-

ニューラルネットワークによる心磁界解析

日本生体磁気学会誌/日本生体磁気学会8(1)1995年05月-

境界要素法によるてんかんの焦点位置推定

日本生体磁気学会誌/日本生体磁気学会8(1)1995年05月-

心磁界解析における体積電流の影響

日本生体磁気学会誌/日本生体磁気学会8(1)1995年05月-

ビスマス系銀シース多芯テープ超電導線材の常電導伝播特性

A. Ishiyama, S.B.Kim,H.Okada,S.Nomura

低温工学/低温工学協会31(7)p.379 - 3901986年07月-

Development of Mice Biomagnetic Measurement System using Dc-SQUID Magnetometer

Yumie Ono, Atsushi Ishiyama, Naoko Kasai, and Akikazu Odawara

IEEE Transaction on Applied Superconductivity

高磁場コイルシステムの研究開発―高磁場MRI 用高温超電導磁石の開発―

宮﨑 寛史, 岩井 貞憲, 戸坂 泰造, 野村 俊自, 来栖 努, 植田 浩史, 野口 聡, 石山 敦士, 浦山 慎一, 福山 秀直

低温工学・超電導学会学会誌 低温工学52(4)p.224 - 233 2332017年08月-

DOI

詳細

概要:A project for developing of RE1Ba2Cu3O7-δ (REBCO) magnets to be utilized in ultrahigh-field magnetic resonance imaging (MRI) was started in 2013. Our final targets are 9.4 T MRI systems for whole-body and brain imaging. In this project, two different development approaches towards the final target were planned. One is a small REBCO coil that can generate 10 Tclass magnetic fields, which is the same level as the target magnetic field. The other is a conduction-cooled 1.5 T REBCO MRI magnet that has a room-temperature bore of 396 mm, which is as large as those of mid-sized model magnets. These results were reflected in the design of a conduction-cooled 9.4 T REBCO magnet for whole-body MRI systems.

Appropriate auditory stimuli for P300 brain-computer interface

Nojo, Hideki;Kawasaki, Minoru;Jyo, Tetsu;Ishiyama, Atsushi;Kasai, Naoko;Ono, Yumie

NEUROSCIENCE RESEARCH68p.E327 - E3272010年-2010年

DOIWoS

詳細

ISSN:0168-0102

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

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

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY20(3)p.1264 - 12672010年-2010年

DOIWoS

詳細

ISSN:1051-8223

Stability and Protection of Coils Wound With YBCO Bundle Conductor

Ueda, Hiroshi;Ishiyama, Atsushi;Shikimachi, Koji;Hirano, Naoki;Nagaya, Shigeo

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY20(3)p.1316 - 13192010年-2010年

DOIWoS

詳細

ISSN:1051-8223

Model Cable Tests for a 275 kV 3 kA HTS Power Cable

Mukoyama, Shinichi;Yagi, Masashi;Yonemura, Tokui;Nomura, Tomoya;Fujiwara, Noboru;Ichikawa, Y.;Aoki, Yuji;Saitoh, Takashi;Amemiya, Naoyuki;Ishiyama, Atsushi;Hayakawa, Naoki

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY21(3)p.976 - 9792011年-2011年

DOIWoS

詳細

ISSN:1051-8223

Over-Current Characteristics of 66-kV RE123 HTS Power Cable

Wang, Xudong;Ishiyama, Atsushi;Ohya, Masayoshi;Fujiwara, Noboru

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY21(3)p.1013 - 10162011年-2011年

DOIWoS

詳細

ISSN:1051-8223

Over-Current Characteristics of 275-kV Class YBCO Power Cable

Ishiyama, Atsushi;Wang, Xudong;Ueda, Hiroshi;Uryu, Toshikuni;Yagi, Masashi;Fujiwara, Noboru

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY21(3)p.1017 - 10202011年-2011年

DOIWoS

詳細

ISSN:1051-8223

Evaluation of Positional Stability in Active Magnetic Levitation Using Spherical HTS Bulk for Inertial Nuclear Fusion

Wang, Tao;Ueda, Hiroshi;Agatsuma, Koh;Ishiyama, Atsushi

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY21(3)p.1579 - 15832011年-2011年

DOIWoS

詳細

ISSN:1051-8223

Numerical Simulation of Current Distribution in Cable-in-Conduit Conductor for ITER TF Coil

Kajitani, Hideki;Ishiyama, Atsushi;Koizumi, Norikiyo;Murakami, Haruyuki;Nakajima, Hideo

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY21(3)p.1964 - 19682011年-2011年

DOIWoS

詳細

ISSN:1051-8223

Quench Behavior and Protection in Cryocooler-Cooled YBCO Pancake Coil for SMES

Ishiyama, Atsushi;Ueda, Hiroshi;Aoki, Yoshiaki;Shikimachi, Koji;Hirano, Naoki;Nagaya, Shigeo

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY21(3)p.2398 - 24012011年-2011年

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ISSN:1051-8223

Degradation of YBCO Coated Conductors Due to an Over-Current Pulse

Ishiyama, Atsushi;Arai, Michio;Momotari, Hiroshi;Wang, Xudong;Ueda, Hiroshi;Saito, Takashi;Aoki, Yuji;Yagi, Masashi;Machi, Takato;Fujiwara, Noboru

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY21(3)p.3025 - 30282011年-2011年

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ISSN:1051-8223

Effect of Neutron Irradiation on High-Temperature Superconductors

Aoki, Toru;Ueda, Hiroshi;Ishiyama, Atsushi;Miyahara, Nobuyuki;Kashima, Naoji;Nagaya, Shigeo

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY21(3)p.3200 - 32022011年-2011年

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ISSN:1051-8223

Quench Detection and Protection of Cryocooler-Cooled YBCO Pancake Coil for SMES

Ueda, Hiroshi;Ishiyama, Atsushi;Muromachi, Kazuki;Suzuki, Takahiro;Shikimachi, Koji;Hirano, Naoki;Nagaya, Shigeo

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY22(3)2012年-2012年

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ISSN:1051-8223

Feasibility Study on a 400 kW-3600 rpm REBCO Fully Superconducting Motor

Iwakuma, Masataka;Ogata, Toshiyuki;Tomoda, Shinichiro;Kisu, Takanobu;Yoshida, Yutaka;Ishiyama, Atsushi;Yamada, Yutaka;Izumi, Teruo;Shiohara, Yuh

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY22(3)2012年-2012年

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ISSN:1051-8223

Overcurrent Tests and Numerical Simulations on a 66-kV-Class RE123 High-Temperature Superconducting Model Cable

Wang, Xudong;Ishiyama, Atsushi;Ohya, Masayoshi;Maruyama, Osamu;Ohkuma, Takeshi

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY22(3)2012年-2012年

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ISSN:1051-8223

Current Margin of 275 KV Class HTS Power Cable With Joint Against Fault Current

Wang, Xudong;Kamiya, Yuji;Ishiyama, Atsushi;Yagi, Masashi;Maruyama, Osamu;Ohkuma, Takeshi

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY22(3)2012年-2012年

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ISSN:1051-8223

Differences in delta wave power between spontaneous and passive perception of ambiguous figures

Nanjo, Tatsuya;Ishiyama, Atsushi;Kasai, Naoko;Ono, Yumie

NEUROSCIENCE RESEARCH71p.E173 - E1732011年-2011年

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ISSN:0168-0102

Nostalgic music enhances asymmetry in EEG power

Hatano, Mari;Ishiyama, Atsushi;Kasai, Naoko;Ono, Yumie

NEUROSCIENCE RESEARCH71p.E269 - E2692011年-2011年

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ISSN:0168-0102

Conceptual Design of Next Generation HTS Cyclotron

Ueda, Hiroshi;Fukuda, Mitsuhiro;Hatanaka, Kichiji;Wang, Tao;Wang, Xudong;Ishiyama, Atsushi;Noguchi, So;Nagaya, Shigeo;Kashima, Naoji;Miyahara, Nobuyuki

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY23(3)2013年-2013年

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ISSN:1051-8223

Spatial and Temporal Behavior of Magnetic Field Distribution Due to Shielding Current in HTS Coil for Cyclotron Application

Ueda, Hiroshi;Fukuda, Mitsuhiro;Hatanaka, Kichiji;Wang, Tao;Ishiyama, Atsushi;Noguchi, So

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY23(3)2013年-2013年

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ISSN:1051-8223

Evaluation of Conduction Cooling Effect of Cryocooler-Cooled HTS Coils for SMES Application

Kotoyori, Takuya;Ohnishi, Hideaki;Masui, Yuta;Ishiyama, Atsushi;Tomonori, Watanabe;Hirano, Naoki;Nagaya, Shigeo;Shikimachi, K.

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY23(3)2013年-2013年

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ISSN:1051-8223

Development of High Strength Pancake Coil With Stress Controlling Structure by REBCO Coated Conductor

Nagaya, Shigeo;Watanabe, Tomonori;Tamada, Tsutomu;Naruse, Mitsuhito;Kashima, Naoji;Katagiri, Toshio;Hirano, Naoki;Awaji, Satoshi;Oguro, Hidetoshi;Ishiyama, Atsushi

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY23(3)2013年-2013年

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ISSN:1051-8223

Critical Current Degradation in High-Temperature Superconducting Tapes Caused by Temperature Rise

Yazaki, Shinjiro;Karasawa, Akira;Kotoyori, Takuya;Ishiyama, Atsushi;Miyahara, Nobuyuki

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY23(3)2013年-2013年

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ISSN:1051-8223

Quench Detection Method for Cryocooler-Cooled YBCO Pancake Coil for SMES

Ohnishi, Hideaki;Ishiyama, Atsushi;Watanabe, Tomonori;Hirano, Naoki;Nagaya, Shigeo

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY23(3)2013年-2013年

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ISSN:1051-8223

Experiments and Numerical Simulations on Local Degradation Characteristics of Coated Conductor Due to Overcurrent

Wang, Xudong;Wang, Tao;Ishiyama, Atsushi;Yagi, Masashi;Maruyama, Osamu;Ohkuma, Takeshi

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY23(3)2013年-2013年

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ISSN:1051-8223

Experiment and Numerical Simulation on Quench Detection in Cryocooler-Cooled YBCO Coil for SMES Application

Masui, Yuta;Wang, Xudong;Ishiyama, Atsushi;Watanabe, Tomonori;Hirano, Naoki;Nagaya, Shigeo;Ueda, Hiroshi

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY24(3)2014年-2014年

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ISSN:1051-8223

Numerical Structural Analysis on a New Stress Control Structure for High-Strength REBCO Pancake Coil

Wang, Xudong;Ishiyama, Atsushi;Tsujimura, Takuya;Yamakawa, Hiroshi;Ueda, Hiroshi;Watanabe, Tomonori;Nagaya, Shigeo

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY24(3)2014年-2014年

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ISSN:1051-8223

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

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

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY24(3)2014年-2014年

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ISSN:1051-8223

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

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

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY24(3)2014年-2014年

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ISSN:1051-8223

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

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

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY25(3)2015年-2015年

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ISSN:1051-8223

Experimental Results of 275-kV 3-kA REBCO HTS Power Cable

Yagi, Masashi;Liu, Jin;Mukoyama, Shinichi;Mitsuhashi, Takaharu;Teng, Jun;Hayakawa, Naoki;Wang, Xudong;Ishiyama, Atsushi;Amemiya, Naoyuki;Hasegawa, Takayo;Saitoh, Takashi;Maruyama, Osamu;Ohkuma, Takeshi

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY25(3)2015年-2015年

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ISSN:1051-8223

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

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

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY25(3)2015年-2015年

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ISSN:1051-8223

イットリウム系超電導電力ケーブル開発の進捗状況

藤原 昇;市川 裕士;雨宮 尚之;石山 敦士;早川 直樹;向山 晋一;八木 正史;増田 孝人;大屋 正義;大松 一也;齊藤 隆;青木 裕治

電気学会研究会資料. ASC, 超電導応用電力機器2010(17)p.45 - 502010年06月-2010年06月 

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66kV系統REBCO超電導モデルケーブルの過電流通電特性

王 旭東;石山 敦士;大屋 正義;藤原 昇

電気学会研究会資料. ASC, 超電導応用電力機器2010(17)p.51 - 552010年06月-2010年06月 

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REBCO超電導線材の交流過電流通電特性

王 旭東;百足 弘史;石山 敦士;大屋 正義;大松 一也;藤原 昇

電気学会研究会資料. ASC, 超電導応用電力機器2010(17)p.57 - 622010年06月-2010年06月 

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次世代超電導サイクロトロンの開発

石山 敦士;植田 浩史;福田 光宏;畑中 吉治;宮原 信幸;横田 渉;鹿島 直二;長屋 重夫

電気学会研究会資料. ASC, 超電導応用電力機器2010(17)p.83 - 882010年06月-2010年06月 

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SMES用伝導冷却YBCO超電導コイルのクエンチ特性と保護

石山 敦士;植田 浩史;式町 浩二;平野 直樹;長屋 重夫

電気学会研究会資料. ASC, 超電導応用電力機器2010(17)p.101 - 1062010年06月-2010年06月 

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異分野融合によるイノベーションの創出

石山 敦士

低温工学45(6)2010年06月-2010年06月 

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詳細

ISSN:03892441

がん治療用重粒子加速器とその超伝導化

石山 敦士;野田 耕司

應用物理80(1)p.24 - 292011年01月-2011年01月 

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ISSN:03698009

66kV/5kA級三心一括型薄膜高温超電導ケーブルの開発

大屋 正義;湯村 洋康;広田 博史;増田 孝人;大松 一也;雨宮 尚之;石山 敦士;丸山 修;大熊 武

電気学会研究会資料. ASC, 超電導応用電力機器2011(1)p.11 - 162011年01月-2011年01月 

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中性子照射による高温超電導線材の特性変化

神林 佑;青木 徹;石山 敦士;宮原 信幸;植田 浩史;鹿島 直二;長屋 重夫

電気学会研究会資料. ASC, 超電導応用電力機器2011(1)p.41 - 452011年01月-2011年01月 

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高温超電導技術を活用した「先進ハイブリッド・サイクロトロン」の開発

石山 敦士;王 旭東;福田 光宏;畑中 吉治;植田 浩史;長屋 重夫;鹿島 直二;宮原 信幸

電気学会研究会資料. ASC, 超電導応用電力機器2011(1)p.47 - 522011年01月-2011年01月 

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66kV級超電導ケーブルにおけるREBCO線材の事故電流に対する裕度評価試験

百足 弘史;新井 道生;児島 健太郎;王 旭東;石山 敦士;大屋 正義;大松 一也;大熊 武;丸山 修

電気学会研究会資料. ASC, 超電導応用電力機器2011(15)p.25 - 302011年01月-2011年01月 

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磁気浮上応用

津田 理;石山 敦士

低温工学46(3)p.94 - 1012011年03月-2011年03月 

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ISSN:03892441

概要:Magnetic levitation systems using HTS bulks, such as magnetic bearing devices for flywheel energy storage systems, transporters, linear actuators, magnetic gears and so on, have been developed by many research groups. Most of the HTS magnetic levitation systems are composed of HTS bulks and permanent magnets. "Stable magnetic levitation without any other control system" is a specific characteristic of the HTS bulks. A non-contact spin processor and a magnetic-levitation seismic isolation device are introduced as magnetic levitation systems that are composed of HTS bulks and permanent magnets. Furthermore, an active magnetic levitation system using spherical HTS bulks for inertial nuclear fusion and a three-dimensional HTS actuator are introduced as magnetic levitation systems with HTS bulks and electromagnets. Levitation force, levitation gap and stability are closely related to the size and shape of the HTS bulk, the magnetic field distribution around the HTS bulk, the conditions in the field-cooling process of the HTS bulk and so on. Achieving large levitation force, large levitation gap and highly stable levitation is very important for practical use of the HTS magnetic levitation system. Theoretical analysis using a numerical simulation code for understanding electromagnetic behaviors within the HTS bulk is useful for improving the levitation force, levitation gap and stability. Finally, numerical techniques based on the finite element method are introduced in this paper.

66kV系統REBCO超電導モデルケーブルの過電流通電試験と数値解析

王 旭東;石山 敦士;大屋 正義;丸山 修;大熊 武

電気学会研究会資料. ASC, 超電導応用電力機器2011(25)p.33 - 382011年06月-2011年06月 

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275kV系統YBCO超電導ケーブルの電流裕度と経年劣化特性

王 旭東;石山 敦士;八木 正史;丸山 修;大熊 武

電気学会研究会資料. ASC, 超電導応用電力機器2011(25)p.39 - 442011年06月-2011年06月 

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SMES応用を想定したYBCOコイルのクエンチ検出と保護

石山 敦士;王 旭東;室町 和輝;式町 浩二;平野 直樹;長屋 重夫;植田 浩史

電気学会研究会資料. ASC, 超電導応用電力機器2011(25)p.45 - 502011年06月-2011年06月 

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「編集委員会」から「学会誌出版委員会」へ

石山 敦士

低温工学 = Cryogenic engineering46(7)2011年07月-2011年07月 

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ISSN:03892441

総論 : 超電導技術の医療応用の現状

石山 敦士

電気学会誌 = The journal of the Institute of Electrical Engineers of Japan132(5)p.276 - 2772012年05月-2012年05月 

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詳細

ISSN:13405551

概要:本記事に「抄録」はありません。

中空フォーマを用いた275kV級YBCO超電導ケーブルの過電流通電特性

王 旭東;石山 敦士;八木 正史;丸山 修;大熊 武

電気学会研究会資料. ASC, 超電導応用電力機器2012(1)p.23 - 282012年06月-2012年06月 

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過電流通電によるYBCO線材の局所劣化特性

王 旭東;石山 敦士;八木 正史;丸山 修;大熊 武

電気学会研究会資料. ASC, 超電導応用電力機器2012(1)p.35 - 402012年06月-2012年06月 

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加速器応用を想定した高温超電導コイルの遮へい電流と磁場分布の空間的・時間的変化の3次元解析

植田 浩史;福田 光宏;畑中 吉治;野口 聡;石山 敦士

電気学会研究会資料. ASC, 超電導応用電力機器2012(1)p.47 - 512012年06月-2012年06月 

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高温超電導線材の加熱による特性変化

矢崎 真二郎;柄澤 彰良;琴寄 拓哉;狩野 開;道辻 健太;有谷 友汰;齋藤 隼;石山 敦士;宮原 信幸

電気学会研究会資料. ASC, 超電導応用電力機器2012(1)p.83 - 862012年06月-2012年06月 

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応用電磁気学 : 超電導機器応用のための電磁界数値解析I : 電磁界数値解析の基礎

植田 浩史;石山 敦士

低温工学 = Cryogenic engineering47(11)p.623 - 6322012年11月-2012年11月 

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ISSN:03892441

特集 : JST S-イノベ「超伝導システムによる先進エネルギー・エレクトロニクス産業の創出」に寄せて

石山 敦士

低温工学 = Cryogenic engineering48(1)2013年01月-2013年01月 

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ISSN:03892441

応用電磁気学 : 超電導機器応用のための電磁界数値解析II : 有限要素法と境界要素法

植田 浩史;石山 敦士

低温工学 = Cryogenic engineering48(2)p.83 - 942013年02月-2013年02月 

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ISSN:03892441

次世代超電導サイクロトロン用コイルの設計最適化

植田 浩史;福田 光宏;畑中 吉治;王 旭東;石山 敦士;野口 聡;鹿島 直二;長屋 重夫;宮原 信幸

電気学会研究会資料. ASC, 超電導応用電力機器2013(1)p.55 - 602013年01月-2013年01月 

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次世代超電導サイクロトロンの開発 : YBCOパンケーキコイルの巻線精度評価

王 韜;狩野 開;道辻 健太;矢崎 真二郎;柄澤 彰良;王 旭東;石山 敦士;宮原 信幸;植田 浩史;鹿島 直二;長屋 重夫

電気学会研究会資料. ASC, 超電導応用電力機器2013(1)p.61 - 662013年01月-2013年01月 

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次世代超電導サイクロトロンの開発 : 高温超電導線材の中性子照射による特性変化

柄澤 彰良;道辻 健太;狩野 開;王 旭東;石山 敦士;植田 浩史;宮原 信幸

電気学会研究会資料. ASC, 超電導応用電力機器2013(1)p.67 - 722013年01月-2013年01月 

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新規補強構造を用いた高強度パンケーキコイルの開発

長屋 重夫;渡部 智則;平野 直樹;淡路 智;小黒 英俊;石山 敦士;王 旭東

電気学会研究会資料. ASC, 超電導応用電力機器2013(1)p.97 - 1022013年01月-2013年01月 

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高温超電導コイルの安定性評価基準とクエンチ検出・保護 : SMES用伝導冷却YBCOコイルを例として

石山 敦士;植田 浩史;王 旭東;長屋 重夫;渡部 智則

低温工学 = Cryogenic engineering48(4)p.141 - 1502013年04月-2013年04月 

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ISSN:03892441

概要:Since high-temperature superconducting (HTS) conductors have a greater volumetric heat capacity at operating temperatures envisaged for practical applications, the possibility of quench caused by a mechanical disturbance such as friction due to wire movement is much lower than that for low-temperature superconducting (LTS) coils. In real applications such as superconducting magnetic energy storage (SMES) systems, however, electrical charging and discharging are repeated and the HTS conductor may deteriorate locally due to cyclic mechanical strain. We also have to consider the possibility of quench caused by a failure in the power supply, cooling system or similar problems. Therefore, a protection scheme assuming quench is also required for HTS coils. In this report, we describe a method of determining the appropriate stabilizer thickness of the YBCOcoated conductors from the perspective of the quench protection of the YBCO coil, which dumps the stored magnetic energy in the coils via external dump resistance. We have been developing a quench detection method for a cryocooler-cooled SMES coil wound with a kA-class laminated bundle conductor composed of an electrically insulated YBCO-coated conductor. Since the normal-zone propagation velocity is quite slow in HTS coils, the detection of a non-recovering normal zone using a voltage signal is quite difficult. Therefore, quench must be detected using some other method. We numerically show that quench in the coil can be detected by observing the transposition of current in the bundle conductor caused by local normal transition. Furthermore, we show the results of experiments on a small model coil wound with a four-YBCO-strand bundle conductor to examine the possibility of a quench detection method by observing the transposition of current in the bundle conductor. This work was mainly supported by the New Energy and Industrial Technology Development Organization (NEDO) as part of the technological development of yttrium-based superconducting power equipment.

高強度パンケーキコイル構造 (Yoroi-coil) の開発

渡部 智則;長屋 重夫;平野 直樹;淡路 智;小黒 英俊;石山 敦士;王 旭東

低温工学 = Cryogenic engineering48(5)p.213 - 2192013年05月-2013年05月 

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ISSN:03892441

概要:A high-strength pancake-coil structure called "Yoroi-coil" (Y-based oxide superconductor and reinforcing outer integrated coil), in which superconducting wire and the reinforcing outer plates of the coil withstand electromagnetic force, was developed for high magnetic field applications. The double-pancake (DP) coil of this coil structure was prepared and verified for durability against electromagnetic forces using the hoop stress test. The coil achieved 1.5 kA transporting at 4.2 K in an 8 T backup magnetic field without degradation of transport properties. Maximum hoop stress at the hoop stress test reached 1.74 GPa, based on the calculations. This result confirmed that the "Yoroi-coil" structure has the capability to withstand large hoop stress, which exceeds the tensile strength of Y-based coated conductors, not only owing to the strength of superconducting wire but also owing to the integration of the whole coil structure itself. Additionally, the strengthening effect of the structure was verified by analysis.

応用電磁気学:超電導機器応用のための電磁界数値解析III : 超電導特性と電磁界解析

植田 浩史;石山 敦士

低温工学 = Cryogenic engineering48(9)p.472 - 4842013年09月-2013年09月 

CiNii

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ISSN:03892441

概要:In this paper, we describe a numerical method for an electromagnetic phenomenon in type-II superconductors containing pins. Models of type-II superconductors containing pins use the eddy current problem of Maxwells equations together with nonlinear constitutive relationships between the electric field (E) and the current density (J). The E-J relationship must lead to basic phenomena of superconductors such as the zero-resistance, flux flow, flux creep, hysteresis and magnetization. As typical models of the E-J relationship in superconductors, the critical state model, the power law "n-value model" and the percolation model are presented. Additionally, as an example, we introduce a superconducting slab, a magnetic shielding type of superconducting fault current limiter and a screening field in a HTS pancake coil.

サブクール窒素冷却によるHTS超電導ケーブルの冷却シミュレーション

佐藤 勇輔;我妻 洸;王 旭東;石山 敦士

電気学会研究会資料. ASC, 超電導応用電力機器2013(22)p.43 - 472013年09月-2013年09月 

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高強度REBCOパンケーキコイルの数値構造解析

王 旭東;石山 敦士;辻村 拓弥;山川 宏;植田 浩史;渡部 智則;長屋 重夫

電気学会研究会資料. ASC, 超電導応用電力機器2013(22)p.81 - 862013年09月-2013年09月 

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SMES用伝導冷却YBCOモデルコイルの常電導転移検出実験・解析評価

荒川 一誠;南 克彦;中田 恵理香;増井 裕太;王 旭東;石山 敦士;渡部 智則;長屋 重夫;植田 浩史

電気学会研究会資料. ASC, 超電導応用電力機器2013(22)p.87 - 922013年09月-2013年09月 

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高温超電導コイルの遮蔽電流と磁場分布の測定実験および解析

植田 浩史;福田 光宏;畑中 吉治;野口 聡;齋藤 隼;有谷 友汰;狩野 開;道辻 健太;王 韜;王 旭東;石山 敦士

電気学会研究会資料. ASC, 超電導応用電力機器2013(22)p.101 - 1062013年09月-2013年09月 

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次世代超電導サイクロトロンの開発 : YBCOダブルパンケーキコイルの巻線精度評価

梅田 大貴;齋藤 隼;有谷 友汰;狩野 開;道辻 健太;王 韜;王 旭東;石山 敦士;植田 浩史;渡部 智則;長屋 重夫

電気学会研究会資料. ASC, 超電導応用電力機器2013(22)p.107 - 1122013年09月-2013年09月 

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SSAを用いた脳波SSVEPの2クラス判別(BCI/BMIとその周辺,一般)

白鳥 友規;南波 寛直;松本 隆;石山 敦士

電子情報通信学会技術研究報告. NC, ニューロコンピューティング113(315)p.13 - 162013年11月-2013年11月 

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ISSN:0913-5685

概要:脳波(EEG)を用いたSSVEPの2クラス判別問題に信号分離アルゴリズムStationary Subspace Analysis(SSA)を適用した。源波形、分離信号ともにFFTを行い特徴量としSVMによる判別を行い比較を行った。その結果分離信号から得た特徴量を用いた場合、源波形から得る特徴量よりも被験者12人中11人で判別率の向上が見られた。また判別率の平均でも91.4%から96.2%へと向上することが確認できた。

特集「イットリウム系超電導電力機器技術開発プロジェクト」に寄せて

石山 敦士

低温工学46(6)p.319 - 3192011年-2011年

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ISSN:0389-2441

応用電磁気学:超電導機器応用のための電磁界数値解析I:― 電磁界数値解析の基礎 ―

植田 浩史;石山 敦士

低温工学47(11)p.623 - 6322012年-2012年

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ISSN:0389-2441

概要:Recently, electromagnetic analysis techniques have come into wide use and have become powerful tools for equipment design thanks to performance upgrades in computer technology. Users of these techniques deal with electromagnetic analysis as "black boxes." However, minimum knowledge relating to "black boxes" is required in order to prevent belief in incorrect results of the electromagnetic analysis. Therefore, in this basic course, the finite element method (FEM) and the boundary element method (BEM), which are the typical methods of electromagnetic field analysis, are described. Additionally, we show that the superconducting characteristic is built into these methods. This time, we describe the governing equation of electromagnetic analysis and the interpolation of the electromagnetic field in the discretization space.

超電導電力貯蔵システム (SMES)

渡部 智則;石山 敦士

電気学会誌134(8)p.546 - 5482014年-2014年

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ISSN:1340-5551

概要:本記事に「抄録」はありません。

特集「超電導発見から100 年」に寄せて

石山 敦士;島崎 毅

低温工学46(12)p.S2 - S22011年-2011年

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ISSN:0389-2441

特集:JST S –イノベ「超伝導システムによる先進エネルギー・ エレクトロニクス産業の創出」に寄せて

石山 敦士

低温工学48(1)p.2 - 22013年-2013年

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ISSN:0389-2441

SOBINMFによる眼電自動除去システム

椿田 紘久;小野 弓絵;石山 敦士

電気学会論文誌. C135(8)p.954 - 9622015年-2015年

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ISSN:0385-4221

概要:This paper introduces a novel method to automatically remove electro-oculogram (EOG) from electroencephalogram (EEG) using second-order blind identification (SOBI) and nonnegative matrix factorization (NMF). To demonstrate the effectiveness of the proposed method, we applied SOBI, NMF, or combined SOBI and NMF (SOBINMF) to the EEG data during motor imagery task in which participants imagined moving their left or right hand. Ocular artifacts were removed more effectively in our proposed SOBINMF method compared to SOBI or NMF alone.

波状曲げ変形を受けたNb3Sn 素線の臨界電流特性評価手法の開発

梶谷 秀樹;石山 敦士;我妻 洸;村上 陽之;辺見 努;小泉 徳潔

低温工学50(12)p.608 - 6152015年-2015年

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ISSN:0389-2441

概要:A cable-in-conduit (CIC) conductor using Nb3Sn strand is applied to an ITER TF coil. The Nb3Sn strand in the conductor is periodically bent due to electromagnetic force, which causes degradation of performance. This degradation should be evaluated to predict conductor critical current performance. In a past study, a numerical simulation model was developed to evaluate the superconductivity of a periodically bent single strand. However, this model is not suitable for application to strands in the conductor because of the extensive calculation time required. The author thus developed a new analytical model with a much shorter calculation time to evaluate the performance of periodically bent strand. This new model uses the classical model concept of a high transverse resistance model (HTRM). The calculated results show good agreement with the test results of a periodically bent Nb3Sn strand in a ends fixed beam model while there was little error in the uniformly bent model under high transverse load due to the difference in bending moment distribution between the two models. However, for both cases, the newly developed model has a much shorter calculation time than that required for numerical simulation. This indicates that a more practical solution can be achieved when evaluating the performance of periodically bent strands. Thus, the model developed in this study can be applied to evaluation of the performance of conductor incorporating many strands.

特集「ITER-CS インサート・コイルの実験結果」に寄せて

石山 敦士;高橋 良和

低温工学51(4)p.96 - 962016年-2016年

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ISSN:0389-2441

インターネット依存傾向と相関する安静時脳機能的結合指標の抽出

伊澤 俊;刀川 賢太;小野 弓絵;小林 浩;栗城 眞也;石山 敦士

生体医工学55(1)p.39 - 442017年-2017年

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ISSN:1347-443X

概要:

The number of patients with internet addiction disorder (IAD), especially among school-age children, is on the rise. Development of objective examination technique to assist the current diagnostic methods using medical interview and inquiry tests is desirable for detection of IAD at its early stage. In this study, we extracted the values of functional connectivity (FC) that correlated with a tendency of IAD, using resting-state functional magnetic resonance imaging (rs-fMRI) data. We recruited 40 males [mean age (SD): 21.9 (0.9) years] with no neurological disorders, conducted rs-fMRI recordings for 7 min 30 s, and administered five questionnaires including internet addiction test (IAT), to assess their mental states. The IAT scores of all participants were in the range of healthy to a tendency of IAD. The FC values were calculated using the cross-correlation of time-series signals in a low frequency band (0.017 to 0.09Hz) between all possible connections of brain region pairs defined by Automated Anatomical Labeling (AAL). For each region pair, we calculated Pearson's correlation coefficients "γ" between the FC values and the scores of IAT as well as other inventories for psychological states, in all subjects. The "γ" were subjects-cross-validated, and the FC of the survived region pairs were statistically assessed by correction of multiple comparison. Finally, we obtained some region pairs in which FC specifically correlated with the IAT scores, but not with other psychological scores. These pairs had mostly negative "γ" over long-distance connections across right and left brain hemispheres. The results suggested that the functional connectivity between specific brain regions was significantly degraded already at the stage prior to the onset of IAD. We expect that our connectivity method can be an objective tool for detecting a tendency of IAD to assist the present diagnostic methods.

高磁場コイルシステムの研究開発

宮﨑 寛史;岩井 貞憲;戸坂 泰造;野村 俊自;来栖 努;植田 浩史;野口 聡;石山 敦士;浦山 慎一;福山 秀直

低温工学52(4)p.224 - 2332017年-2017年

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概要:

A project for developing of RE1Ba2Cu3O7-δ (REBCO) magnets to be utilized in ultrahigh-field magnetic resonance imaging (MRI) was started in 2013. Our final targets are 9.4 T MRI systems for whole-body and brain imaging. In this project, two different development approaches towards the final target were planned. One is a small REBCO coil that can generate 10 Tclass magnetic fields, which is the same level as the target magnetic field. The other is a conduction-cooled 1.5 T REBCO MRI magnet that has a room-temperature bore of 396 mm, which is as large as those of mid-sized model magnets. These results were reflected in the design of a conduction-cooled 9.4 T REBCO magnet for whole-body MRI systems.

Strengthening effect of 'Yoroi-coil structure' against electromagnetic force

Watanabe, Tomonori; Nagaya, Shigeo; Hirano, Naoki; Awaji, Satoshi; Oguro, Hidetoshi; Tsuchiya, Yuji; Omura, Takuya; Nimori, Shigeki; Shimizu, Tadashi; Ishiyama, Atsushi; Wang, Xudong; Wang, Xudong

IEEE Transactions on Applied Superconductivity25(3)2015年06月-2015年06月 

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ISSN:10518223

概要:© 2002-2011 IEEE. The strengthening of Yoroi-coil (Y-based oxide superconductor and reinforcing outer integrated coil) structure at stronger electromagnetic force was investigated using the Yoroi-coil structured double-pancake coil with higher strength outer plates of carbon-fiber reinforced plastic (C-FRP) than those of glass-FRP. The coil achieved 1.14 kA transporting at 4.2 K in 14-T back-up magnetic field and the superconducting wire was burnt by thermal runaway after that. The calculated maximum hoop stress, based on the BJR (magnetic field × current density × coil radius) calculations, at the hoop stress test reached 2.0 GPa. This value was far exceeding the tensile strength of superconducting wire ranging from 1 to 1.3 GPa; however, the maximum strain of superconducting wire in the test coil was held about 0.5%. Yoroi-coil structure is useful for the applications, which need high magnetic field precision. The strengthening effect of C-FRP outer plates was observed at outer part of the coil, but it did not cover the whole coil body, so that arrangement of reinforcing outer plates could admit of some improvement.

Evaluation of magnetic-field distribution by screening current in multiple REBCO coils

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

IEEE Transactions on Applied Superconductivity25(3)2015年06月-2015年06月 

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ISSN:10518223

概要:© 2014 IEEE. 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.

Charging behavior in no-insulation REBCO pancake coils

Wang, Xudong; Wang, Xudong; Wang, Tao; Nakada, Erika; Ishiyama, Atsushi; Itoh, Ryusei; Noguchi, So

IEEE Transactions on Applied Superconductivity25(3)2015年06月-2015年06月 

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ISSN:10518223

概要:© 2002-2011 IEEE. This paper presents analytical studies on the charging characteristics of a no-insulation (NI) REBCO pancake coil. A partial element equivalent circuit (PEEC) model has been developed to evaluate the local current paths in NI REBCO pancake coils. The PEEC model is able to consider the asymmetry of the coil winding, the partial turn-to-turn contact electrical resistance, and the partial self and mutual inductances. The analysis results are compared with previous charging experimental results and simulations using a simplified parallel equivalent circuit (SPEC) model to validate the proposed approach with the PEEC model. To investigate the charging characteristics of a meter-class NI REBCO pancake coil, numerical simulations were performed by using the PEEC and SPEC models as a parameter of the turn-to-turn contact electrical resistance. In addition, the magnetic field in a 3-T NI REBCO coil was calculated by the SPEC model to clarify the charging delay of a practical scale magnet.

Development of non-circular REBCO pancake coil for high-temperature superconducting cyclotron

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

IEEE Transactions on Applied Superconductivity25(3)2015年06月-2015年06月 

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ISSN:10518223

概要:© 2002-2011 IEEE. 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 and mechanical 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.

Experimental results of 275-kV 3-kA REBCO HTS power cable

Yagi, Masashi; Liu, Jin; Mukoyama, Shinichi; Mitsuhashi, Takaharu; Teng, Jun; Hayakawa, Naoki; Wang, Xudong; Wang, Xudong; Ishiyama, Atsushi; Amemiya, Naoyuki; Hasegawa, Takayo; Saitoh, Takashi; Maruyama, Osamu; Ohkuma, Takeshi

IEEE Transactions on Applied Superconductivity25(3)2015年06月-2015年06月 

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ISSN:10518223

概要:© 2002-2011 IEEE. A 30-m-long 275-kV 3-kA high-temperature superconducting (HTS) cable had been developed in a national project of the Materials and Power Applications of Coated Conductors project in Japan. The design of the cable was based on the design values obtained from ac loss properties, thermal behavior under short-circuit tests, and electrical properties, such as partial discharge properties, impulse withstand properties, and dielectric properties. Through the development, the material of the cable insulation was determined and designed on the basis of its design stresses and test conditions based on the IEC, JEC (Japan electrical standards), and other HTS demonstrations. This cable was also designed to withstand a short-circuit test of 63 kA for 0.6 s and to have low losses of 0.8 W/m at 3 kA, 275 kV, including ac loss and dielectric loss. Based on these designs, a 50-m cable was manufactured and tested. The short samples obtained from 50 m were confirmed to have the designed characteristics. Furukawa Electric constructed a demonstration system of a 30-m cable with two terminations and a cable joint. The demonstration had started since November 2012 at Shenyang in China. In this demonstration, a 30-day long-term test was conducted and monitored at a current of 3 kA and at a test voltage selected to verify a 30-year operational lifetime. Removal tests revealed the superior reliability of the 275-kV HTS cable system.

Reduction of irregular magnetic field generated by screening current in REBCO coil

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

IEEE Transactions on Applied Superconductivity25(3)2015年06月-2015年06月 

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ISSN:10518223

概要:© 2002-2011 IEEE. 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.

Analyses of transient behaviors of no-insulation REBCO pancake coils during sudden discharging and overcurrent

Wang, Tao; Noguchi, So; Wang, Xudong; Arakawa, Issei; Minami, Katsuhiko; Monma, Katsutoshi; Ishiyama, Atsushi; Hahn, Seungyong; Iwasa, Yukikazu

IEEE Transactions on Applied Superconductivity25(3)2015年06月-2015年06月 

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ISSN:10518223

概要:© 2002-2011 IEEE. Stability margin of a high-temperature superconducting (HTS) coil is two or three orders of magnitude greater than that of a low-temperature superconducting coil. In recent years, many papers have reported test results of turn-to-turn no-insulation (NI) HTS coils having extremely enhanced thermal stability, such that burnout never occurs in an NI coil, even at an operating current exceeding 2.5 times the critical current. Thus, The main goal of this paper is to clarify transient electromagnetic and thermal behaviors and mechanism of the high thermal stability in an NI REBCO coil. A partial element equivalent circuit (PEEC) model is proposed for the numerical simulation of an NI REBCO coil, which considers a local electrical contact resistance between turns, an $I\mbox{ - } V$ characteristic of an REBCO tape, and local self and mutual inductances of the NI REBCO coil. Using the PEEC model, we investigate the influence of the turn-to-turn contact resistance on the transient behavior of the NI REBCO coil during sudden discharging. We also perform thermal conduction analyses with the PEEC model to clarify the transient behavior of an NI REBCO coil during an overcurrent operation.

Temperature and pressure simulation of a high-temperature superconducting cable cooled by subcooled LN2 with fault current

Sato, Yusuke; Agatsuma, Koh; Wang, Xudong; Wang, Xudong; Ishiyama, Atsushi

IEEE Transactions on Applied Superconductivity25(3)2015年06月-2015年06月 

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ISSN:10518223

概要:© 2002-2011 IEEE. A computer simulation has been developed to estimate the transient temperature and pressure distributions in a high-temperature superconducting (HTS) power cable cooled by a forced flow of subcooled LN2. This simulation is critical for assessing the effects of short-circuit accidents in practical HTS power cables. When a fault occurs, an excessive current of 31.5 kA may flow in a cable for 2 s, and it is important to understand the temperature and pressure profiles in a cable cooled by the forced flow of LN2 when these faults occur until the disturbance flows out from a cable. The temperature profile of the LN2 coolant and the cable cores was analyzed by solving heat conduction and heat transfer equations using the finite-difference method. The Cryodata GASPAK software package was used to estimate the fluid properties. The simulation results show a fairly good agreement with the experimental results. By employing a new model of the induction refrigeration system and the circulation pump, a small discrepancy is resolved in pressures between simulation and experiment. The analysis results show that the pressure in the cable significantly changes depending on the initial gas volumes in the terminals and the volume of the LN2 gas that evaporates from the copper former in the cable.

Magnetocardiograms early detection of pulmonary arterial hypertension using inverse problem analysis in rat model

Yasuda, Shotaro; Higano, Sho; Ishiyama, Atsushi; Ono, Yumie; Kajimura, Ichige; Minamisawa, Susumu

Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBS2015-Novemberp.4475 - 44782015年11月-2015年11月 

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ISSN:1557170X

概要:© 2015 IEEE.Utilizing small animal magnetocardiograms (MCG), we have developed a diagnostic method to detect the development of pulmonary hypertension (PH) in a rat heart. We obtained multiple MCG of rats with monocrotaline-induced PH and monitored the development of pathophysiological conditions. Current dipole estimation was then applied to determine the association between abnormal propagation of the cardiac excited wavefront and disease states. The progress of right ventricular hypertrophy correlated with a decrease in the angles of the current dipoles during R and S waves. In addition, clear changes in the current dipole angles during S waves were observed 9-19 days before the availability of echocardiographic diagnosis of the PH. Our results showed, using a rat PH model, that continuous monitoring of myocardial conditions allows PH to be detected at an earlier stage than echocardiographic screening.

Evaluation of performance to detect default mode network among some algorithms applied to resting-state fMRI data

Tachikawa, Kenta; Izawa, Shun; Ono, Yumie; Kuriki, Shinya; Ishiyama, Atsushi

Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBS2015-Novemberp.1805 - 18082015年11月-2015年11月 

PubMedDOIScopus

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ISSN:1557170X

概要:© 2015 IEEE.Significant correlation exists in the blood-oxygen-level-dependent (BOLD) signals of resting-state fMRI across different regions in the brain. These regions form the default mode network (DMN), salience network (SN), sensory networks, and others. Among these, the DMN is widely investigated in relation to various mental diseases. Several analytic methods are available for obtaining the DMN activity from individuals' fMRI time-series signals, but a fully effective method has not yet been established. In the present study, we examined a functional connectivity analysis and three algorithms of blind source separation including independent component analysis, second-order blind identification, and non-negative matrix factorization using a set of resting-state fMRI data measured for twelve young participants. Results showed that the second-order blind identification yielded superior performance for the DMN detection, indicating significant activation in all DMN regions based on statistical parametric maps.

Transient Behaviors of No-Insulation REBCO Pancake Coil during Local Normal-State Transition

Ikeda, Aika; Oki, Takahiro; Wang, Tao; Ishiyama, Atsushi; Monma, Katsutoshi; Noguchi, So; Watanabe, Tomonori; Nagaya, Shigeo

IEEE Transactions on Applied Superconductivity26(4)2016年06月-2016年06月 

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ISSN:10518223

概要:© 2015 IEEE.Recently, no-insulation (NI) winding techniques have been proposed for achieving high current density and high thermal stability. To verify the excellent characteristics achieved using these techniques, we investigated the transient behaviors of NI REBCO pancake coils. In this paper, we evaluate transient electromagnetic and thermal behaviors during a local normal-state transition, based on a partial element equivalent circuit and thermal coupled numerical analysis. Moreover, we investigate temporal and spatial current distributions in the NI coil winding after a local normal transition occurs. We also clarify the reason for the suppression of temperature increase caused by the local normal-state transition in the NI winding. Subsequently, we evaluate the influence of the thickness of a Cu stabilizer on the thermal stability of the NI and conventional insulation windings. Finally, we discuss the mechanism of high thermal stability attained in the NI coil winding technique.

Investigation of Current Flow between Turns of NI REBCO Pancake Coil by 2-D Finite-Element Method

Noguchi, So; Monma, Katsutoshi; Igarashi, Hajime; Ishiyama, Atsushi

IEEE Transactions on Applied Superconductivity26(3)2016年04月-2016年04月 

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ISSN:10518223

概要:© 2002-2011 IEEE.The no-insulation (NI) winding technique for an NI ReBCO pancake coil is expected to improve dynamic and thermal stability and enhance current density. The investigations on electromagnetic and thermal behaviors are important for the development of NI ReBCO coils. Many stability investigations of the NI ReBCO coil itself have been carried out by experiments and simulations. However, the detailed behavior of the bypass current between turns has not been shown. Although contact resistivity was obtained through prior experiment, it included the resistivity of not only contact surface but also the components, i.e., the copper stabilizer and the Hastelloy substrate, of a ReBCO tape. To investigate the detailed bypass current behavior in this paper, the true contact surface resistivity is taken into account in the simulation. The bypass current on the cross section of the NI ReBCO tape is simulated using the two-dimensional finite-element method. From the simulation results, the influence of the coil-radial resistivity between turns on the turn-to-turn contact surface resistivity is clarified. In addition, the heat loss is also reported, and a simple equivalent circuit of the turn-to-turn contact is proposed.

Experimental Results of Screening-Current Field with 10-T Class Small REBCO Coil

Iwai, S.; Miyazaki, H.; Ohtani, Y.; Tosaka, T.; Tasaki, K.; Nomura, S.; Kurusu, T.; Ueda, H.; Ueda, H.; Noguchi, S.; Noguchi, S.; Ishiyama, A.; Urayama, S.; Fukuyama, H.

IEEE Transactions on Applied Superconductivity26(4)2016年06月-2016年06月 

DOIScopus

詳細

ISSN:10518223

概要:© 2002-2011 IEEE.A REBCO-coated conductor has a tape shape and is suitable for forming a stack of single pancakes for generating a high magnetic field. However, the magnetic flux going through the tape surface causes a screening current, which reduces the magnetic field in conventional coil designs. Magnetic resonance imaging systems need high uniformity of the magnetic field, both spatially and temporally, and thus, the screening field resulting from the screening current is one of the critical issues. In this paper, a 10-T class small test coil using REBCO-coated conductors was fabricated and tested in a conduction-cooled configuration from 10 to 60 K for investigating the effect of the screening field on the generated magnetic field in the inner space of the coil. The coil was composed of a stack of 22 single pancakes using 4-mm-wide REBCO tapes with an inner diameter of 50 mm, an outer diameter of 129 mm, and a height of 104 mm. For different stacking orders based on the coil critical currents, the measured values of the central magnetic field at 10 K were 7.66 and 8.27 T, which were lower than the calculated values of 8.07 and 8.70 T obtained without taking account of the screening-current fields.

Numerical Simulation on Magnetic Field Generated by Screening Current in 10-T-Class REBCO Coil

Ueda, Hiroshi; Imaichi, Yohei; Wang, Tao; Ishiyama, Atsushi; Noguchi, So; Iwai, Sadanori; Miyazaki, Hiroshi; Tosaka, Taizo; Nomura, Shunji; Kurusu, Tsutomu; Urayama, Shinichi; Fukuyama, Hidenao

IEEE Transactions on Applied Superconductivity26(4)2016年06月-2016年06月 

DOIScopus

詳細

ISSN:10518223

概要:© 2016 IEEE.In a REBCO superconducting magnet for magnetic resonance imaging (MRI) applications, the large screening current induced by a magnetic field perpendicular to the winding tape is a serious problem: it generates irregular magnetic field that deteriorates the spatial field homogeneity and temporal field stability in MRI applications. Therefore, we need to estimate the magnetic field generated by the screening current using electromagnetic field analysis to design and develop a REBCO magnet that generates highly accurate and stable magnetic field. Therefore, to examine the influence of the magnetic field generated by the screening current, we constructed cryocooler-cooled small bore-coil stacked pancake REBCO coils with an inner diameter of 50 mm. This coil generates a magnetic field of 10 T at the center. In this study, we report the evaluation of the current distribution and magnetic field in the REBCO coil using the developed 3-D numerical simulation code for electromagnetic field analysis in a REBCO tape using the finite-element method and fast multipole method. The numerical results agree well with the experimental results. Furthermore, we discuss the current distribution in the REBCO tape and the spatial and temporal behavior of the magnetic field on the basis of the results of the experiments and numerical simulation.

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

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

IEEE Transactions on Applied Superconductivity26(3)2016年04月-2016年04月 

DOIScopus

詳細

ISSN:10518223

概要:© 2002-2011 IEEE.Development of a higherature superconducting magnet wound with REBa2Cu3O7-δ (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-current-induced 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 roomerature 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.

Experiment and Numerical Analysis on the YOROI Structure for High-Strength REBCO Coil

Wang, Xudong; Tsuji, Yoshiaki; Ishiyama, Atsushi; Yamakawa, Hiroshi; Watanabe, Tomonori; Nagaya, Shigeo

IEEE Transactions on Applied Superconductivity26(4)2016年06月-2016年06月 

DOIScopus

詳細

ISSN:10518223

概要:© 2016 IEEE.To achieve a high current density and a compact REBCO coil, a reinforcing structure is essential to prevent coil degradation and deformation caused by the large Lorentz force. A new reinforcing structure for the REBCO coil called the Y-based oxide superconductor and reinforcing outer integrated (YOROI) coil was proposed in the previous study. The YOROI coil, which exhibited no degradation after an excitation test with a maximum hoop stress of 1.7 GPa at 4.2 K in 8-T backup fields, 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. In this study, the hoop stress in the winding and the stress shared by the reinforcing structure of a YOROI model coil were measured at 40 K in 10-T backup fields to clarify the reinforcing mechanism of the YOROI coil. A three-dimensional structural analysis, which simulated the experimental condition, was performed on the model coil to determine the distribution of stress and strain in the winding and reinforcing structure.

Experiment and Simulation of Impregnated No-Insulation REBCO Pancake Coil

Noguchi, So; Monma, Katsutoshi; Iwai, Sadanori; Miyazaki, Hiroshi; Tosaka, Taizo; Nomura, Shunji; Kurusu, Tsutomu; Ueda, Hiroshi; Ishiyama, Atsushi; Urayama, Shinichi; Fukuyama, Hidenao

IEEE Transactions on Applied Superconductivity26(4)2016年06月-2016年06月 

DOIScopus

詳細

ISSN:10518223

概要:© 2015 IEEE.It is important to investigate the stability and behavior of an epoxy-resin-impregnated no-insulation (NI) REBCO pancake coil to implement high-field applications, such as ultra-high-field magnetic resonance imaging. We have performed sudden discharging and overcurrent tests for the impregnated NI REBCO pancake coil. From the discharging test, the contact resistivity is estimated, and it changes depending on the initial current. From the overcurrent test, the high thermal stability of the impregnated NI REBCO pancake coil is confirmed. The REBCO pancake coil is charged up to 67 A though the critical current is only 46 A, and no degradation has been found. To investigate in detail the electromagnetic behavior of an impregnated NI REBCO pancake coil, the simulation is performed by means of the partial element equivalent circuit (PEEC) model. In the sudden discharging test, the simulation results for the case of lower initial current are in good agreement with the experimental data. As can be inferred from the simulation results, the current drastically decreases from the inside of the impregnated NI REBCO pancake coil. The result of the overcurrent simulation is almost identical to the experimental one. However, since the contact resistivity is presumed to be constant in the simulation, the difference is observed in the high current region.

Temperature and pressure simulation of a 1.5-km HTS power cable cooled by Subcooled LN2 with a fault current

Yasui, Tetsuo; Sato, Yusuke; Agatsuma, Koh; Ishiyama, Atsushi; Wang, Xudong; Wang, Xudong; Ohya, Masayoshi; Masuda, Takato; Honjo, Shoichi

IEEE Transactions on Applied Superconductivity26(3)2016年04月-2016年04月 

DOIScopus

詳細

ISSN:10518223

概要:© 2002-2011 IEEE.Waseda University has developed computer programs to estimate the transient temperature and pressure distributions in a high-temperature superconducting (HTS) power cable cooled by a forced flow of subcooled LN2. This simulation is crucial for realizing a practical HTS power cable to assess the effects of short-circuit accidents. When a short-circuit accident occurs, a fault current of 31.5 kA with a duration of 2 s may flow in a cable in the worst case, which is the Japanese criterion for a 66-kV transmission line. The temperature profiles of the LN2 coolant and cable cores were analyzed by solving the heat conduction and heat transfer equations using a finite-difference method. The pressure profiles of the LN2 coolant were calculated using Fanning's equation. For practical use, it was assumed that HTS cables that are a few kilometers long will be adopted. In this study, an evaluation of the stability of a 1.5-km HTS cable with a fault current of 31.5 kA over 2.0 s was performed using our computer program. According to the results, the temperature of the LN2 coolant at the outlet reached the saturation temperature after the fault, and vaporization suddenly occurred. The evaporated gas was released from the outlet to the terminal.

Evaluation of irregular magnetic field generated by screening current in REBCO coils for high accuracy field

Matsumi, Ayako; Ueda, Hiroshi; Noguchi, So; Wang, Tao; Ishiyama, Atsushi; Miyazaki, Hiroshi; Tosaka, Taizo; Nomura, Shunji; Kurusu, Tsutomu; Urayama, Shinichi; Fukuyama, Hidenao

IEEE Transactions on Applied Superconductivity26(4)2016年06月-2016年06月 

DOIScopus

詳細

ISSN:10518223

概要:© 2002-2011 IEEE.In recent years, research and development of applications for a high field magnet wound with a REBCO tape into nuclear magnetic resonance and magnetic resonance imaging have been carried out. These applications require a very high accuracy field, that is, the spatial uniform and temporally stable field. However, in the REBCO coils, the irregular magnetic field is generated by the screening current, which is remarkably induced by the radial component of the magnetic field in a REBCO tape. Therefore, a nonconventional approach is required for the reduction or correction of the irregular magnetic field generated by the screening current in the stage of design for a high-accuracy-field REBCO coil. The prediction and improvement of the irregular magnetic field generated by the screening current is a serious issue for the development and design of REBCO coils and correction shims.

RandD Project on HTS Magnets for Ultrahigh-Field MRI Systems

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

IEEE Transactions on Applied Superconductivity26(4)2016年06月-2016年06月 

DOIScopus

詳細

ISSN:10518223

概要:© 2016 IEEE.An RandD project on higherature superconducting (HTS) magnets using (RE)Ba2Cu3O7 (REBCO; RE=rare earth) wires for ultrahigh-field (UHF) magnetic resonance imaging (MRI) systems is described. Our targets are 9.4-T MRI systems for whole-body imaging and brain imaging. REBCO wires are promising components for UHF-MRI because REBCO wires have high critical current density in high magnetic fields and high strength against hoop stresses, which allows MRI magnets to be smaller and lighter than conventional ones. The aim of the project is to establish basic magnet technologies for adapting REBCO coils for UHF-MRI. The project term is three years, and this year is the final year. We have already demonstrated the generation of an 8.27-T magnetic field with a small test coil composed of 22 REBCO pancake coils. A magnetic field spatial distribution with inhomogeneity of several hundreds of parts per million within 100-mm diameter spherical volume (DSV) was demonstrated with a 1-T model magnet. A stable magnetic field of a few parts per million per hour was also demonstrated with the 1-T model magnet. The targets of the project, to be achieved by March 2016, are to demonstrate the generation of a 9.4-T field with the small REBCO coil, and to demonstrate a homogeneous magnetic field in 200-mm DSV with a 1.5-T magnet having three pairs of split coils. Imaging will be performed with the 1.5-T magnet.

Evaluation of Magnetic Field Distribution by Screening Current in Multiple REBCO Coils

Mochida, Ayumu; Ueda, Hiroshi; Noguchi, So; Wang, Tao; Ishiyama, Atsushi; Miyazaki, Hiroshi; Tosaka, Taizo; Nomura, Shunji; Kurusu, Tsutomu; Urayama, Shinichi; Fukuyama, Hidenao

IEEE Transactions on Applied Superconductivity26(4)2016年06月-2016年06月 

DOIScopus

詳細

ISSN:10518223

概要:© 2002-2011 IEEE.Coil systems are fabricated with various combinations of multiple coils in order to generate homogenous fields for NMR and MRI applications. In multiple coil systems using REBCO coils, the behavior of the screening current, which deteriorates field homogeneity, depends on the patterns of the transport current, the charging sequence of the coils, and the various resulting magnetic fields. It is therefore important to investigate and clarify the behavior of the irregular magnetic field and screening current in multiple coil systems under different operating environments. In a previous study, we experimentally and numerically clarified the different behaviors of irregular magnetic fields based on the charging sequence of coils in multiple-model REBCO coils [1], [2]. In this paper, we constructed the multiple-model REBCO coils in order to obtain the fundamental data for reducing or improving the resulting irregular magnetic field. Furthermore, the distribution of the irregular magnetic field in terms of the screening current was measured by using the reversal current method [3], [4]. We also calculated the spatial and temporal behavior of the irregular magnetic field by using our developed 3-D numerical simulation. Based on the experimental and numerical results, we discuss the behavior of the magnetic field in terms of the screening current when using the current sweep reversal method in multiple-model REBCO coils.

Evaluation on Quench Protection for No-Insulation REBCO Pancake Coil

Oki, Takahiro; Ikeda, Aika; Wang, Tao; Ishiyama, Atsushi; Noguchi, So; Monma, Katsutoshi; Watanabe, Tomonori; Nagaya, Shigeo

IEEE Transactions on Applied Superconductivity26(4)2016年06月-2016年06月 

DOIScopus

詳細

ISSN:10518223

概要:© 2002-2011 IEEE.We have been developing a no-insulation (NI) winding technique to be used in both high thermal stability and high current density, which have a tradeoff relationship. This paper presents numerical and experimental studies on the thermal stability of an NI REBCO pancake coil by focusing on a quench protection scheme. In the case of an accident or a local normal-state transition, the power supply for the superconducting coil must be immediately shut down in order to ensure its safety. During the sudden discharging of a conventional insulated winding coil, most of the stored electromagnetic energy is dissipated by an external dump resistor connected across the coil terminals as a quench protection system. However, in an NI pancake coil, current flows in the radial direction in order to bypass the local normal-state area to the adjacent turns. The stored energy in the coil may be dissipated as Joule heat owing to the turn-to-turn contact electrical resistance. In this study, by using experiments and numerical analyses, we evaluated two transient behaviors during sudden discharging: the distribution of energy dissipation and the temperature increase in model NI REBCO pancake coils. We also evaluated the thermal behavior of the NI coil during a local normal transition.

Design of a conduction-cooled 9.4 T REBCO magnet for whole-body MRI systems

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

Superconductor Science and Technology29(10)2016年08月-2016年08月 

DOIScopus

詳細

ISSN:09532048

概要:© 2016 IOP Publishing Ltd.A project on the development of REBa2Cu3O7-δ (REBCO) magnets for ultra-high-field magnetic resonance imaging (MRI) was started in 2013. Since REBCO-coated conductors feature high mechanical strength under tensile stress and high critical current density, use of REBCO coils would allow superconducting magnets to be made smaller and lighter than conventional ones. In addition, a conduction-cooled superconducting magnet is simpler to use than one cooled by a liquid helium bath because the operation and maintenance of the cryogenic system become simpler, without the need to handle cryogenic fluid. Superconducting magnets for MRI require homogeneous, stable magnetic fields. The homogeneity of the magnetic field is highly dependent on the coil shape and position. Moreover, in REBCO magnets, the screening-current-induced magnetic field, which 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, a 1 T model magnet and some test coils were fabricated. From an evaluation of the 1 T model magnet, it was found that the main reason for magnetic field inhomogeneity was the tolerances in the z-axis positions of the coils, and therefore, it is important to control the gap between the single pancakes. In addition, we have already demonstrated the generation of an 8.27 T central magnetic field at 10 K with a small test coil. The screening-current-induced magnetic field was 0.43 T and was predictable by using an electromagnetic field simulation program. These results were reflected in the design of a conduction-cooled 9.4 T REBCO magnet for whole-body MRI systems. The magnet was composed of six main coils and two active shield coils. The total conductor length was 581 km, and the stored energy was 293 kJ. The field inhomogeneity was 24 ppm peak to peak and 3 ppm volume-root-mean-square (VRMS) for a 500 mm diameter spherical volume (DSV). The axial and radial 5 gauss line locations were less than 5 m and 4.2 m respectively.

Optimal configuration design of MRI REBCO magnet taking into account superconducting layer

Noguchi, So; Miyazaki, Hiroshi; Tosaka, Taizo; Nomura, Shunji; Kurusu, Tsutomu; Ueda, Hiroshi; Ishiyama, Atsushi; Urayama, Shinichi; Fukuyama, Hidenao

IEEE CEFC 2016 - 17th Biennial Conference on Electromagnetic Field Computation2017年01月-2017年01月 

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詳細

概要:© 2016 IEEE.The development of ultra-high-field (∼10 T magnetic resonance imaging (MRI) device is underway. It is, therefore, required to achieve the extremely high field homogeneity at a magnet design stage, where the field homogeneity is evaluated using the Legendre polynomials. Commonly, it is supposed that the current uniformly flows on the cross section of coils. However, for REBCO magnet, the no-current-flowing region has to be taken into account, such as a copper stabilizer. In addition, the REBCO layer inside REBCO tape is very thin, 1-2 μm, so the current-flowing region is 1/100 of the REBCO tape area. Therefore, it is necessary to consider that the current flows only in the REBCO layer, for accurate evaluation of field homogeneity.

An accelerated computation method of Legendre polynomial coefficients for MRI REBCO magnet design

Noguchi, So; Noguchi, So; Miyao, Ryosuke; Igarashi, Hajime; Ishiyama, Atsushi

IEEE CEFC 2016 - 17th Biennial Conference on Electromagnetic Field Computation2017年01月-2017年01月 

DOIScopus

詳細

概要:© 2016 IEEE.When designing an MRI magnet, its field homogeneity is evaluated by higher-order coefficients of the Legendre polynomial expression than 0th. Recently, the development of ultra-high-field (∼10 T) MRI magnet wound with REBCO tapes is underway. REBCO tapes are flat, and its current-carrying region is very narrow compared to its cross section. However, to compute the higher-order coefficients for MRI REBCO magnet is a labor task because the current-carrying region is discretely arranged. In this paper, we propose an accelerated method of computing the higher-order coefficients of the Legendre polynomials for MRI REBCO magnet design using a shift operator.

Electromagnetic analysis on magnetic field and current distribution in high temperature superconducting thin tape in coil winding

Ueda, Hiroshi; Kim, Seok Beom; Noguchi, So; Ishiyama, Atsushi; Miyazaki, Hiroshi; Iwai, Sadanori; Tosaka, Taizo; Nomura, Shunji; Kurusu, Tsutomu; Urayama, Shinichi; Fukuyama, Hidenao

IEEE CEFC 2016 - 17th Biennial Conference on Electromagnetic Field Computation2017年01月-2017年01月 

DOIScopus

詳細

概要:© 2016 IEEE.High temperature superconducting (HTS) wires are high aspect ratio cross-section tapes. Therefore, the applications of HTS tapes lead to various problems such as AC loss, non-uniform current, and screening current. In practice, we must investigate the detail of current distribution in HTS tapes using the electromagnetic analysis technique dealing with high aspect ratio tape and nonlinearity of superconductor. We developed the numerical simulation code of electromagnetic field analysis in HTS tape using a finite element method (FEM) and fast multipole method (FMM).

書籍等出版物

超電導エネルギー工学

仁田旦三編著・石山敦士ほか

オーム社2006年 08月-

詳細

ISBN:4-274-20281-X

フィニッシュ電験三種—機械③—

小貫天編修,石山敦士 他

オーム社1996年 06月-

フィニッシュ電験三種 機械 3

オーム社1996年 03月-

特許

整理番号:377

心臓磁気計測装置(日本, アメリカ)

石山 敦士, 小野 弓絵

特願2004-053973、特開2005-237781、特許第4276107号

整理番号:918

コイルシステム及びこれを用いた粒子加速器(日本)

石山 敦士, 植田 浩史, 野口 聡

特願2009- 55551、特開2010-212029、特許第5414312号

整理番号:919

コイルシステム及びこれを用いた粒子加速器(日本)

石山 敦士, 植田 浩史, 野口 聡

特願2009- 55555、特開2010-212030、特許第5420932号

整理番号:920

磁場形成装置及びこれを用いた粒子加速器(日本)

植田 浩史, 野口 聡, 石山 敦士

特願2009-055556、特開2010-212031、特許第5524494号

整理番号:1079

空芯型サイクロトロン(日本)

石山 敦士, 植田 浩史

特願2013-215694、特開2015- 79626、特許第6255549号

整理番号:1080

空芯型サイクロトロン(日本)

石山 敦士, 植田 浩史

特願2010-252226、特開2012-104386、特許第5708984号

整理番号:1082

空芯型サイクロトロン(日本)

石山 敦士, 植田 浩史

特願2010-132256、特開2011-258427、特許第5682903号

整理番号:1351

超電導コイルのクエンチ検出装置及びクエンチ検出方法(日本)

石山 敦士

特願2013-108293、特開2014-229753

整理番号:1399

超電導線材及びそれを用いた超電導コイル(日本)

石山 敦士

特願2013-101848、特開2014-222615

外部研究資金

科学研究費採択状況

研究種別:

核廃棄物処理のための大出力サイクロトロン用超伝導コイルシステムの設計研究

2014年-0月-2016年-0月

配分額:¥3770000

研究種別:

次世代重粒子線がん治療装置用超伝導加速器の基盤技術開発

2011年-0月-2014年-0月

配分額:¥48750000

研究種別:

普及型重粒子線癌治療装置用超伝導コイルシステム開発のための基礎的研究

配分額:¥18720000

研究種別:

バルク超伝導体の特性評価と応用のための基礎的研究

配分額:¥7600000

研究種別:

新構成の角棒状リニアハイブリッドモータの開発とその実用化に関する研究

配分額:¥2600000

研究種別:

交流用超伝導ケーブル導体の安定性向上と応用のための基礎的研究

配分額:¥8800000

研究種別:

有限要素法および境界要素法を用いた電気機器における電磁力解析手法の開発

配分額:¥1900000

研究種別:

超伝導ケーブル導体の過渡安定性に関する研究

配分額:¥7600000

研究種別:

磁界の強さを変数とする有限要素法と境界要素法の併用による三次元渦電流場の解析

配分額:¥1900000

研究種別:

交流用超電導導体の電磁的・熱的特性に関する研究

配分額:¥1300000

研究種別:

有限要素法と境界要素法の併用による三次元うず電流場の解析

配分額:¥2500000

研究種別:基盤研究(A)

次世代医療用サイクロトロン開発のための5H超伝導コイルシステムの基盤技術の確立

2014年-2017年

研究分野:電力工学・電力変換・電気機器

配分額:¥31590000

研究種別:

次世代医療用高温超伝導スケルトン・サイクロトロンの設計原理・開発基盤の確立

2018年-0月-2023年-0月

配分額:¥193440000

研究種別:

次世代医療用高温超伝導スケルトン・サイクロトロンの設計原理・開発基盤の確立

2018年-0月-2022年-0月

配分額:¥44850000

研究種別:

超高磁場・超高貯蔵密度を実現する革新的高温超伝導コイル化技術に関する基礎研究

2016年-0月-2018年-0月

配分額:¥3510000

研究種別:

高温超伝導磁石の高機械強度設計技術の開発

2014年-0月-2016年-0月

配分額:¥4030000

研究種別:

次世代医療用サイクロトロン開発のための5H超伝導コイルシステムの基盤技術の確立

2014年-0月-2018年-0月

配分額:¥41340000

研究種別:

高磁場・高精度磁場を指向した高温超伝導マグネット設計に関する研究

2013年-0月-2016年-0月

配分額:¥4940000

研究資金の受入れ状況

提供機関:文部科学省

環境共生型高精度エネルギー予測/高効率エネルギー利用技術1998年-2002年

提供機関:文部科学省

太陽光自立電源システムの開発研究1997年-2001年

提供機関:文部科学省

光ネットワーク終端機器に対する太陽光無停電電源システムの研究開発プロジェクト1999年-2003年

実施形態:受託教育

超電導交流応用に関する基礎研究1994年-1998年

実施形態:受託教育

高磁界高温超電導SMESの通電安定性1999年-1999年

実施形態:受託教育

酸化物超電導線材の評価1999年-1999年

学内研究制度

特定課題研究

交流用超電導ケーブル導体の電磁的・熱的特性に関する研究

1995年度共同研究者:小貫 天, 若尾 真治

研究成果概要:1. 交流用ケーブル導体の常電導伝播特性素線絶縁の施されていない3本,7本および(6+1)本(7本中,中心素線1本を銅または銅ニッケル線としたもの)撚線ケーブル導体の常電導転移(クエンチ)特性を明確にするための実験と解析を行った。...1. 交流用ケーブル導体の常電導伝播特性素線絶縁の施されていない3本,7本および(6+1)本(7本中,中心素線1本を銅または銅ニッケル線としたもの)撚線ケーブル導体の常電導転移(クエンチ)特性を明確にするための実験と解析を行った。(1) クエンチ実験:3本撚線ケーブル導体を試料として,1本を選択的にヒータにより強制的に常電導転移させたときの,撚線ケーブル導体内の電流再配分現象と,導体全体が常電導状態へ転移する最少のヒータ投入熱量を測定した。その結果,従来の直流用ケーブル導体とは異なる特有のクエンチ特性を有することが示された。(2) クエンチ解析:初年度(94年度)開発したケーブル導体内の電流分布と温度分布を解析する計算機コードを用い,3本撚線ケーブル導体について解析を行った。実験結果との比較により,その妥当性の確認を行うとともに,実験によって示された特有のクエンチ特性についてその発生機構について考察を行った。その上で,3本,7本および(6+1)本撚線ケーブル導体について解析・シミュレーションを行い,母材である銅ニッケルの電気抵抗率と熱伝導率や,素線間の接触電気および熱抵抗などのクエンチ特性に与える影響,銅シース(素線表面に設けた銅の薄い層)の過渡安定性への寄与などを明確にした。2. 素線間接触電気抵抗の精密測定 撚線ケーブルタイプの超電導導体の安定性を評価するためには,導体内の電流分布を支配するパラメータの一つである素線間の微小な接触電気抵抗を正確に知る必要がある。超電導トランスを用いた新しい測定法を提案・試作し,10-9〔Ω〕という微小抵抗の測定が可能となり,成形撚線型導体について実測し貴重なデータを得ることができた。

超伝導交流機器に関する基礎研究

1998年度共同研究者:小貫 天, 若尾 真治, 金 錫範

研究成果概要:1. 交流用超伝導撚線導体の過渡安性評価 銅複合化による安定性の向上効果について実験と三次元数値シミュレーションによる評価を行った。線径、マトリクス比、B-J特性(臨界磁界―臨界電流密度特性)がほぼ等しく、銅の配置のみ異なる3種類...1. 交流用超伝導撚線導体の過渡安性評価 銅複合化による安定性の向上効果について実験と三次元数値シミュレーションによる評価を行った。線径、マトリクス比、B-J特性(臨界磁界―臨界電流密度特性)がほぼ等しく、銅の配置のみ異なる3種類の線材と銅を含まない線材を素線とする3本撚線導体(合計4種類)を用意し、各通電電流値における最小クエンチエネルギー(素線1本をヒータにより強制的に常電導転移させ、その後3本撚線導体全体が常電導転移する最小のヒータ投入熱量)を評価基準として実験を行った。その結果、銅複合化により安定性が飛躍的に向上し、最小クエンチエネルギーとしては1~3桁の向上があった。銅複合化により、攪乱熱を有効に拡散できること、、常電導転移に伴う素線間電流再分配時のジュール発熱密度を抑えることができることなどを明らかにした。2. 超伝導垂直円筒型リニア誘導モータの試作・試験 モータの超電導化に当たっては、速度トルク特性などの回転機としての通常の動作特性とは別に、超伝導巻線の交流損失や巻線に加わる電磁力などに対しモータが安定に動作するよう設計・製作する必要がある。本研究は、超電導交流機器実現へ向けて、実運転環境下における超電導巻線の振舞を明確にするための検討を行うため、その対象機器として最適と考えた円筒型短一次リニア誘導モータの試作(97年度)・試験(98年度)を行った。動作試験では、始動トルク特性、二次導体(アルミ円筒体)駆動特性をはじめ、クエンチ(常電導転移)検出・保護装置の動作確認や、無効電力補償(力率改善)などについて検証実験が行われ良好な結果が得られた。今後、同試作機を用いて二次導体突入・脱出時の機械的攪乱の影響や交流損失低減についてさらに検討を進めていく予定である。

核廃棄物処理のための大出力超伝導サイクロトロンの設計研究

2013年度

研究成果概要: 今後の原子力発電のゆくえは極めて不透明な状況にあるが、放射性廃棄物処理の問題はそのいかんに関わらず原子力分野最大の課題の1つであり、最終処理場の選択や処理技術開発については将来世代に委ねねばならないという厳しい状況となっている。... 今後の原子力発電のゆくえは極めて不透明な状況にあるが、放射性廃棄物処理の問題はそのいかんに関わらず原子力分野最大の課題の1つであり、最終処理場の選択や処理技術開発については将来世代に委ねねばならないという厳しい状況となっている。

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