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
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
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
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
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
長嶋 賢
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.5, pp.351-358, 2019-09-20 (Released:2019-11-12)
参考文献数
26
被引用文献数
1 1

A flywheel energy storage system can stabilize the fluctuating output of a solar photovoltaic power generation system, and it can also improve the efficiency of a railway system. To increase storage capacity, Railway Technical Research Institute (RTRI) has invented superconducting magnetic bearings with superconducting coils and bulk superconductors. That is, “total-superconducting magnetic bearing.” RTRI have started with basic research concerning “total-superconducting magnetic bearing,” and developed several prototypes of flywheel energy storage systems using “total-superconducting magnetic bearing.”At last, a demonstration machine for superconducting flywheel energy storage systems has been developed as a joint project of five enterprises subsidized by the New Energy and Industrial Technology Development Organization. This paper describes the background and outline of the research and development of this superconducting flywheel energy storage system.
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 4

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
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 2

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
吉田 誠至
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.6, pp.349-354, 2018-11-20 (Released:2018-12-28)
参考文献数
3
被引用文献数
2 2

The space cryogenics cooling system for the X-ray spectrometer installed on the ASTRO-H is introduced in this report. ASTRO-H is an X-ray astronomy satellite that the Japan Aerospace Exploration Agency (JAXA) developed to support studying the evolution of the universe and other physical phenomena yet to be discovered. The primary scientific instrument installed on the ASTRO-H is a soft X-ray spectrometer (SXS). Its detectors are cooled to 50 mK using a complex cryogenic system with a multistage adiabatic demagnetization refrigerator (ADR) developed by the National Aeronautics and Space Administration (NASA), and a cryogenics system developed by Sumitomo Heavy Industries, Ltd. (SHI). SHI’s cryogenics system is needed to cool the heatsink of the ADR to 1.3 K or less while in orbit, and is capable of doing so for three years or longer. To meet these requirements, SHI developed a hybrid cryogenics system consisting of a liquid helium tank, a 4 K cooler, and two two-stage Stirling coolers. ASTROH was launched from Tanegashima Space Center on February 17, 2016. Initial operation of the SXS cryogenics system in orbit has been completed successfully. The cooling performance was as expected and may exceed the lifetime requirement of three years.
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.54, no.4, pp.275-282, 2019-07-20 (Released:2019-08-01)
参考文献数
51
被引用文献数
3 2

We discuss the physics of superconducting resonant cavities for particle accelerators, including the basics of a superconducting cavity, Meissner state stability, and surface resistance together with related scientific and technological challenges. Ongoing research and some proposals for solving the challenges are also discussed.
著者
永井 啓一
出版者
CRYOGENICS AND SUPERCONDUCTIVITY SOCIETY OF JAPAN
雑誌
低温工学 (ISSN:03892441)
巻号頁・発行日
vol.22, no.5, pp.298-307, 1987-10-25 (Released:2010-02-26)
参考文献数
4

The development program of the H-II Rocket has been initiated in 1985, and now engineering model test is being progressed. The H-II Rocket is a new expendable launch vehicle to meet a demand of space activities in the 1990's, with capability of placing a 2 ton class satellite into geostationary earth orbit (GEO). After trade-off studies, LOX/LH2 propulsion system with a single main engine (LE-7) of staged combustion cycle has been selected for the 1st stage of the H-II Rocket, considering its high performance and the accumulated experience in cryogenic propulsion system technology through development of the 2nd stage (LOX/LH2) of the H-I Rocket, of which the first test flight was successfully launched in August, 1986. And the 2nd stage propulsion system will be developed by upgrading modification (tank volume increase and engine thrust up) of the H-I Rocket 2nd stage. This paper shows an outline of the propulsion systems of H-II Rocket 1st and 2nd stages, and the technical problem including the technics which was gained in the development of H-I 2nd stage propulsion system.
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.