著者

春山 富義

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.8, pp.317-317, 2005 (Released:2005-10-28)

著者

永松 純

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.56, no.6, pp.351-355, 2021 (Released:2021-11-20)

参考文献数

2

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

被引用文献数

3

---

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

菅井 保宏

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.53, no.5, pp.269, 2018-09-20 (Released:2018-10-27)

著者

平松 良朗

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.56, no.3, pp.125-129, 2021 (Released:2021-05-20)

参考文献数

1

---

Helium is a typical carrier gas for GC-MS systems and is a limited and valuable material. Here, we introduce alternative gas analysis technologies that utilize hydrogen and nitrogen. When hydrogen is utilized in a GC-MS system, it is more sensitive and has better separation than nitrogen. On other hand, in the case of nitrogen, it is easier to handle as compared to hydrogen. In this paper, basics gas chromatography is explained, and the gas analysis technologies using hydrogen and nitrogen as an alternative to helium gas are described. These technologies will contribute to reducing the consumption of helium.

著者

久保 毅幸

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.56, no.5, pp.277-282, 2021 (Released:2021-09-21)

参考文献数

35

---

Microscopic theory of the depairing current density (jd) is briefly reviewed for the applied-superconductivity communities. The goal of this article is to introduce the Kupriyanov-Lukichev-Maki theory of jd for s-wave superconductors in the diffusive limit, which is the most reliable calculation of jd based on the BCS theory and is relevant to various superconducting devices. The effect of subgap states on jd is also discussed.

著者

向井 寛人 朝永 顕成 蔡 兆申

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.53, no.5, pp.278-286, 2018-09-20 (Released:2018-10-27)

参考文献数

60

---

Research towards the realization of superconducting quantum computers is progressing rapidly. Recently, the number of integrated quantum bits (qubits) has begun to exceed 50 bits, and such quantum system has the potential capability to surpass that of any classical computer (quantum supremacy). To improve gate fidelity, research on qubits and surrounding environments are actively being studied. Which superconducting circuit will become the platform for quantum computers? What kind of technologies and theory will be used for quantum computers? In this paper, we cover many issues leading towards the realization of quantum computing systems.

著者

山本 純也

出版者

公益社団法人 低温工学・超電導学会

雑誌

低温工学 (ISSN:03892441)

巻号頁・発行日

vol.11, no.5, pp.222-228, 1976-11-10 (Released:2010-02-26)

参考文献数

4

---

This article describes methods of measuring liquid helium quantity, preparing a transfer tube, experimental set up of a cryostat, precooling, and transfering liquid helium, The properties of liquid helium are also simply explained for beginners. Precooling by liquid nitrogen is strongly recommended for decreasing liquid helium consumption.

著者

中島 洋

出版者

CRYOGENICS AND SUPERCONDUCTIVITY SOCIETY OF JAPAN

雑誌

低温工学 (ISSN:03892441)

巻号頁・発行日

vol.37, no.4, pp.148-156, 2002-04-25 (Released:2010-02-26)

参考文献数

11

---

The development of a superconducting Maglev system in Japan was started more than 30 years ago. Since 1997, the running tests have been successfully continued on the Yamanashi test line. A manned run in 1999 attained a speed of 552km/h, The Yamanashi test results proved a remarkable stability of the onboard superconducting magnet system, In these 30 years, we have encountered many difficult problems during this development. In this paper, the history of the Maglev development will be introduced with focus on these problems, especially in regard to the superconducting magnets and onboard refrigerators.

著者

富田 優

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.48, no.11, pp.562-568, 2013-10-25 (Released:2014-01-20)

参考文献数

11

被引用文献数

3 3

---

DC electric railway systems are widely used in Japan, including in metropolitan areas. However, they have some problems, such as limited use of regenerative brakes and energy losses. In order to solve these problems, and to attain the essential energy savings for next-generation electric railway systems, we have been studying the feasibility of applying superconducting power cables to DC electric feeder systems. In this study, investigations regarding effective use of regenerative brakes, loss reduction, etc., have been carried out on the assumption that the substations concerned are connected with each other by superconducting power cables placed in parallel with the feeder line. This research was supported by the Japan Science and Technology Agency, JST, under the strategic promotion of innovative research and development.

著者

伊藤 大佐

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.37, no.11, pp.587, 2002

著者

田中 宗 棚橋 耕太郎 本橋 智光 高柳 慎一

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.53, no.5, pp.287-294, 2018-09-20 (Released:2018-10-27)

参考文献数

34

被引用文献数

2 1

---

Quantum annealing (QA) is a promising calculation method for obtaining a better solution to combinatorial optimization problems. QA is a natural computation technique proposed in the context of statistical physics in 1998. In 2011, the world's first commercial machine realizing QA experimentally was released. After that, the development of hardware and software has been exhaustive, and the studies on application search have been done using commercial QA machines. In this paper, we first explain the basics of QA without assuming the knowledge of statistical physics and quantum physics. We also show a couple of examples of application studies on QA. In addition, existing problems and overcoming other methods are explained.

著者

山内 邦仁

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.53, no.3, pp.130-137, 2018-05-20 (Released:2018-07-14)

参考文献数

12

被引用文献数

1 1

---

The superconducting Satellite Tokamak machine, “JT-60SA,” under construction at the National Institutes for Quantum and Radiological Science and Technology (QST) is an international collaborative project between Japan and Europe. It consists of superconducting toroidal and poloidal field coils, and some normal conductive in-vessel coils. This commentary describes the key features of the overall circuit configuration and the expected performance of each component of the power supply system for the superconducting magnets in JT-60SA.

著者

柳 長門 伊藤 悟 寺﨑 義朗

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.54, no.1, pp.10-22, 2019-01-20 (Released:2019-02-11)

参考文献数

56

被引用文献数

1 3

---

Aiming at application to future fusion reactor magnets, the development of large-current capacity high-temperature superconducting (HTS) conductors has started around the world. The present status of various conductor concepts and their properties are introduced. Future prospects are also discussed.

著者

鈴木 厚人

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.42, no.1, pp.1, 2007 (Released:2007-04-03)

被引用文献数

1

著者

富岡 章 能瀬 眞一 八木 裕治郎

出版者

CRYOGENICS AND SUPERCONDUCTIVITY SOCIETY OF JAPAN

雑誌

低温工学 (ISSN:03892441)

巻号頁・発行日

vol.41, no.1, pp.28-35, 2006

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We have developed the production technology for HTS magnets used in power transformers. Two subjects were mainly studied (i.e., high-voltage technologies and large current and low AC loss technologies) to establish the production method for a 66 kV / 6.9 kV 10 MVA-class HTS power transformer. In order to verify the validity of the elemental technologies, a single-phase 66 kV / 6.9 kV 2 MVA-class model HTS transformer was manufactured and tested. The test results indicate that the elemental technologies established can be used for the development of a 66 kV / 6.9 kV 10 MVA-class HTS power transformer.

著者

中島 良 佐藤 和雄 甲斐 美香 小林 良雄

出版者

公益社団法人 低温工学・超電導学会

雑誌

低温工学 (ISSN:03892441)

巻号頁・発行日

vol.27, no.2, pp.152-157, 1992-04-25 (Released:2010-02-26)

参考文献数

10

---

Resistance vs. temperature relations of 200 carbon resistors (Allen Bradley 100Ω, 1/8W), widely used for cryogenic temperature measurements, were investigated in the range between liquid helium temperature and 20K. Obtained data are statistically evaluated, and it is apparently shown that the difference of the carbon resistor's lot affects the resistance value at the cryogenic temperatures. Four empirical formulas for the resistance vs. temperature relation proposed by other researchers are evaluated. According to this result, the equation, logR+K/logR=A+B/T, proposed by Clement et al. has most precise fitting below 10K. The authors propose a new empirical equation by applying Clement's equation. It is found that the three undecided coefficients, A, B and K of the equation can be calculated from the resistance at 4.2K alone, thus enabling one-point calibration at liquid helium temperature. Resistance changes caused by ten times temperature cyclings from room temperature to liquid helium temperature are also measured. These are within -0.05-+0.02K, though measurments are slightly diverged by temperature cyclings.

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 2

---

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

梅本 勝弥 柳本 俊之

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.47, no.6, pp.377-383, 2012-06-25 (Released:2013-02-16)

参考文献数

12

被引用文献数

9 4

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Although the application of superconductivity technologies to rotating machines has been studied since the 1970s, it has not yet been made practicable. However, due to the recent rapid improvements in high-temperature superconductor performance, high-temperature superconducting motors for ship propulsion are approaching a level where they can be utilized. In this article, the current status of R&D on high-temperature superconducting motors for ship propulsion being developed by Kawasaki Heavy Industries Ltd. (KHI) and its cooperative research groups is reported. In particular, the aims, content and plans of two projects being led by KHI will be shown. The first one is the New Energy and Industrial Technology Development Organization (NEDO) energy-saving project, and the second one is the Japan Science and Technology Agency (JST) SInnovation project. Finally, a roadmap and further studies related to the practical application of high-temperature superconducting motors for ship propulsion are shown.

著者

井上 廉

出版者

CRYOGENICS AND SUPERCONDUCTIVITY SOCIETY OF JAPAN

雑誌

低温工学 (ISSN:03892441)

巻号頁・発行日

vol.30, no.8, pp.369-376, 1995-08-25 (Released:2010-02-26)

参考文献数

12

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The hybrid magnet, which is a large system composed of an inner water-cooled magnet and an outer superconducting magnet, is well known to be the most suitable for generating steady high-magnetic fields. Thirty T-class hybrid magnets are being operated at several high-magnetic field laboratories, The world's highest steady field at present is 35.2T. Projects to enhance the steady fields up to 40-45T are progressing now at the National Research Institute for Metal, Japan, and the National High Magnetic Field Laboratory, USA. In particular, the NRIM project is just now nearing the final stage. In this article, I review in detail the hybrid magnet technology including those of superconducting magnet and water-cooled magnet, the present status of hybrid magnet systems in operation, and the developing projects at NRIM.