著者
神原 陽一
出版者
公益社団法人 低温工学・超電導学会 (旧 社団法人 低温工学協会)
雑誌
低温工学 (ISSN:03892441)
巻号頁・発行日
vol.52, no.6, pp.383-388, 2017-11-20 (Released:2017-12-08)
参考文献数
83

After obtaining my doctorate in engineering from Keio University, I spent five years as a researcher at the Tokyo Institute of Technology, Suzukakedai Campus in Yokohama. During that time, I made the first report on a material system called iron-based high-temperature superconductors (Fe-SCs). Research on Fe-SCs is still hot topic in condensed matter physics. Now, I am continuing my research mainly on the fabrication of superconducting wire using Fe-SCs, while being distracted by some traditional affairs as a member of the faculty. Research on Fe-SCs has encouraged young researchers towards the further discovery of novel layered superconductors. This article was prepared by updating the content of “A Private Story, Discovery of Iron-based High Tc Superconductors” previously published in the membership journal of the Physical Society of Japan (Nihon Butsuri Gakkaishi).
著者
吉田 清
出版者
公益社団法人 低温工学・超電導学会 (旧 社団法人 低温工学協会)
雑誌
低温工学 (ISSN:03892441)
巻号頁・発行日
vol.44, no.8, pp.346-352, 2009 (Released:2009-10-15)
参考文献数
17
被引用文献数
1 1

The upgrading of the JT-60U to the JT-60SA has started in a joint effort by the Japanese government (JA) and European commission (EU) under the framework of the Broader Approach (BA) Agreement. The superconducting magnet system for the JT-60SA consists of 18 toroidal field (TF) coils, a central solenoid (CS) with four modules, and six equilibrium field (EF) coils. The TF case encloses the winding pack and is the main structural component of the magnet system. The CS consists of independent winding pack modules, which are hung from the top of the TF coils through its pre-load structure. The six EF coils are attached to the TF coil case through supports with flexible plates that allow radial displacement. The CS modules operate at high field and use a Nb3Sn superconductor. The TF coils and EF coils use NbTi superconductors. This paper describes the technical requirements, operational interface and detailed manufacturing design outline of the superconducting magnet system for the JT-60SA.
著者
川島 健司 伊豫 彰 荻野 拓
出版者
公益社団法人 低温工学・超電導学会 (旧 社団法人 低温工学協会)
雑誌
低温工学 (ISSN:03892441)
巻号頁・発行日
vol.52, no.6, pp.389-396, 2017-11-20 (Released:2017-12-08)
参考文献数
46

We report discoveries and properties of new 112-type (Ca,Ln)FeAs2 (Ln = La ~ Gd) and 1144-type AeAFe4As4(Ae = Ca, Sr, Ba, Eu, A = K, Rb, Cs) Fe-based superconductor structures. (Ca,Ln)FeAs2 has a monoclinic system with a space group P21/m composed of two Ca(Pr) planes, Fe2As2 layers, and As2 zigzag chain layers. (Ca,Ln)FeAs2 shows superconductivity with a transition temperature (Tc) at 20 ~ 40 K. Although (Ca,Ln)FeAs2 has thick blocking layers, it has relatively high critical current density over 106 A/cm2 at 5 K (self-field). AeAFe4As4 has a tetragonal system with a space group, P4/mmm, Ae and A layers are inserted alternately between the Fe2As2 layers in the c-axis direction. AeAFe4As4 is a stoichiometric compound having Tc = 31 ~ 36 K, depending only on the combination of Ae and A. Both new superconductors are promising materials for application due to their characteristic properties.
著者
田中 雅光 藤巻 朗 井上 弘士
出版者
公益社団法人 低温工学・超電導学会 (旧 社団法人 低温工学協会)
雑誌
低温工学 (ISSN:03892441)
巻号頁・発行日
vol.52, no.5, pp.323-331, 2017-09-20 (Released:2017-10-27)
参考文献数
50

The recent trend and perspectives for high-performance microprocessors based on superconductor single-fluxquantum (SFQ) logic families are described. The rapid single-flux-quantum (RSFQ) and its energy-efficient derivatives are promising as a next-generation digital circuit technology for very-large-scale integration in the post-Moore's era because of the capability of ultrahigh-frequency operation over 100 GHz and low energy consumption. Several ongoing research projects as well as results reported, including several demonstrations of SFQ-based microprocessors and their components, are reviewed.
著者
池田 博 土井 浩一郎 福田 洋一 野口 隆志 中嶋 俊哉 飯村 憲 渋谷 和雄
出版者
公益社団法人 低温工学・超電導学会 (旧 社団法人 低温工学協会)
雑誌
低温工学 (ISSN:03892441)
巻号頁・発行日
vol.39, no.8, pp.348-353, 2004 (Released:2008-03-10)
参考文献数
8
被引用文献数
3 3

From February 2003 to January 2004, a new superconducting gravimeter with a cryocooler was installed to replace the former device at the Syowa station in Antarctica. The new gravimeter has a high sensitivity of one nano-gal and is being used to survey the earth's core in the Global Geodynamics Project. A new type of diaphragm was confirmed to well isolate the vibration from the refrigerator cold-head and effectively prevent solid air contamination. A remote monitoring system from Japan is also going to be installed.
著者
東川 甲平 井上 昌睦 木須 隆暢
出版者
公益社団法人 低温工学・超電導学会 (旧 社団法人 低温工学協会)
雑誌
低温工学 (ISSN:03892441)
巻号頁・発行日
vol.49, no.9, pp.485-493, 2014-09-25 (Released:2014-10-24)
参考文献数
15

This article reviews a method for characterizing the local critical current density (Jc) distribution in superconducting tapes and wires based on scanning Hall-probe microscopy (SHPM). This method is very powerful for (1) finding the bottleneck that limits the global performance of a superconductor, (2) investigating the local inhomogeneity that may become the origin of local quench, especially in HTS applications, (3) establishing the processes for narrow and/or multifilamentary HTS conductors for reducing the magnetization in magnet applications and the AC losses in power applications. The principle and the functions of this technique are introduced by referring to characterization examples of REBCO coated conductors and an MgB2 wire.
著者
林 秀美 永渕 尚志 畑辺 康宏 田口 彰 谷口 俊二 竹内 一浩 有可 光宏 仙波 智行 浅野 克彦 河島 巌 寺薗 完一 高祖 聖一 清水 延彦 辰田 昌功 大崎 博之
出版者
公益社団法人 低温工学・超電導学会 (旧 社団法人 低温工学協会)
雑誌
低温工学 (ISSN:03892441)
巻号頁・発行日
vol.40, no.5, pp.167-174, 2005 (Released:2005-10-28)
参考文献数
13
被引用文献数
3 3

The authors have developed a solenoid model coil to stabilize the power system in superconducting magnetic energy storage (SMES) system with the aim of drastically reducing system cost. The single solenoid model coil is designed with the rated current, maximum magnetic field and coil charge rates equivalent to those of a practical 100 MW/15 kWh-class SMES using multi-pole solenoid coils. In addition, the coil is characterized by the use of a stabilized Al-NbTi CIC conductor that has a graded structure, layered winding and a high magnetic field with a compact design. To verify coil performance, several tests such as a the measurement of rated current and AC loss, high-speed pulse operation, coil quenching, and insulation characteristics were conducted using a model coil at Kyushu Electric's Imajuku testing center. Test results proved that the SMES model coil performs as well as the initially designed coil, while doing so at a drastically reduced cost.
著者
辺見 努 松井 邦浩 小泉 徳潔 中嶋 秀夫 飯島 亜美 酒井 正弘
出版者
公益社団法人 低温工学・超電導学会 (旧 社団法人 低温工学協会)
雑誌
低温工学 (ISSN:03892441)
巻号頁・発行日
vol.47, no.3, pp.172-177, 2012-03-25 (Released:2012-07-04)
参考文献数
6
被引用文献数
3

The manufacturing process for ITER toroidal field (TF) coils must be demonstrated as effective in order to meet the criteria for qualification. Since impregnation of the insulation system is one criterion for qualification in this study, we performed impregnation tests using a cyanate-ester/epoxy blended resin, chosen for its excellent resistance to radiation. To establish the insulation and impregnation procedure in the TF coil manufacturing process, three types of trials were performed: 1) impregnation tests using an acrylic model to fix the impregnation conditions; 2) an impregnation test using a metallic model to confirm that no void remains in the insulation layer after curing in the D-shaped configuration; and 3) insulation and impregnation trials using a 1/3-scale double-pancake (DP) model. The results of these trials were used to determine the insulation and impregnation procedures for manufacturing ITER TF coils.
著者
井口 将秀 千田 豊 中嶋 秀夫 小川 剛史 片山 義紀 小方 大成 峯村 敏幸 宮部 圭介 渡海 大輔 新見 健一郎
出版者
公益社団法人 低温工学・超電導学会 (旧 社団法人 低温工学協会)
雑誌
低温工学 (ISSN:03892441)
巻号頁・発行日
vol.47, no.3, pp.193-199, 2012-03-25 (Released:2012-07-04)
参考文献数
11
被引用文献数
5 2

The Japan Atomic Energy Agency (JAEA) has conducted activities in Japan since March 2009 in order to establish the manufacturing procedure for the ITER toroidal field (TF) coil structures. A TF coil structure consists of a TF coil case and components. The activities include ensuring that the structural materials and welding procedure comply with the Japan Society of Mechanical Engineers (JSME) code for fusion devices, and demonstrating the manufacturing method and procedures using full-scale segments of the TF coil structure. From the results of these activities, the JAEA confirmed that the quality control method of actual series TF coil structures complies with the JSME code. Therefore, the quality of structural materials and weld joints using gas tungsten arc welding (GTAW) satisfy the ITER requirements. In addition, the JAEA obtained knowledge regarding the welding deformation of the actual TF coil structures. This paper describes the results of these compliance and development activities for ITER TF coil structures.
著者
石垣 将宏 石井 克哉
出版者
公益社団法人 低温工学・超電導学会 (旧 社団法人 低温工学協会)
雑誌
低温工学 (ISSN:03892441)
巻号頁・発行日
vol.43, no.12, pp.566-570, 2008 (Released:2009-03-02)
参考文献数
7

Taconis oscillation in a closed long tube is studied by the numerical simulation of two-dimensional compressible Navier-Stokes equations. Conditions are used where both end walls of the tube are hot (T = TH), and the central regions of the side walls are cold (T = TC). The oscillation can be spontaneously generated when the temperature ratio (TH/TC) is larger than 7.1, whereas it can be damped when the temperature ratio is smaller than 5.7. We obtained two different critical temperature ratios and observed the hysteresis phenomenon.