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

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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

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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

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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

石原 昭

出版者

CRYOGENICS AND SUPERCONDUCTIVITY SOCIETY OF JAPAN

雑誌

低温工学 (ISSN:03892441)

巻号頁・発行日

vol.8, no.4, pp.162-166, 1973-09-25 (Released:2010-02-26)

参考文献数

19

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A survey of researches on persistent current switches for superconducting magnets is presented.Basic principles and methods of persistent current switches are given. General characteristics and some problems of thermal type and mechanical type persistent current switches are described including off-state resistance, on-state resistance, stability of switch-superconductor, responce time and consumption of liquid He. Some examples of these switches are given.

著者

竹内 尚輝

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.332-339, 2017-09-20 (Released:2017-10-27)

参考文献数

53

被引用文献数

1 1

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We report recent progress on adiabatic quantum-flux-parametron (AQFP) logic, which is an energy-efficient superconductor logic based on quantum flux parametron (QFP). The switching energy of an AQFP gate can be arbitrarily reduced via adiabatic switching, in which the shape of the potential energy gradually varies between single-well and double-well shapes as the result of using ac excitation magnetic fluxes. First, we show the operation principle of AQFP and explain adiabatic switching in light of potential energy shapes. We also show calculated switching energy and bit error rates to demonstrate that the switching energy of AQFP can be significantly reduced while keeping a low error rate. Then, we report recently developed AQFP subsystems, which include an 8-bit carry look-ahead adder, a register file, and a long-interconnect driver. Our demonstration reveals that AQFP technology is ready to be applied in microprocessor design.

著者

藤巻 朗

出版者

CRYOGENICS AND SUPERCONDUCTIVITY SOCIETY OF JAPAN

雑誌

低温工学 (ISSN:03892441)

巻号頁・発行日

vol.31, no.11, pp.572-577, 1996-11-25 (Released:2010-02-26)

参考文献数

30

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An overview of present Josephson junctions based on high-temperature superconductors (HTSs) is described. I indicate the importance of the critical current-normal resistance (IcRn) product, and show the experimentally-obtained values of the IcRn products for the HTS Josephson junctions reported so far. The junctions include grain boundary junctions, edge junctions, and sandwich junctions. Considering the charge transport mechanism across the junctions, effective ways to increase the IcRn product are proposed.

著者

廣田 憲之

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.55, no.3, pp.185-188, 2020-05-20 (Released:2020-06-04)

参考文献数

14

---

The magneto-Archimedes effect is a technique to enhance the effect of the magnetic force acting on materials by considering the influence of the surrounding medium. Application of this technique as a way of materials separation is known as the magneto-Archimedes separation. The magneto-Archimedes separation enables the separation of many different materials into each component based on the differences in their magnetic susceptibilities and densities irrespective of the particle size. In this topical review, the principle of the magneto-Archimedes effect and its application as a way to separate materials are described and some other examples applying the magneto-Archimedes effect are introduced.

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 5

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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.

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.57, no.4, pp.236-240, 2022 (Released:2022-07-20)

参考文献数

8

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Introducing a superconducting cable is expected to reduce power loss. However, it needs cooling to maintain the superconducting state. In this paper, we outline the superconducting system which consists of superconducting cables and a cooling system. Subsequently, we report the examination of the efficient refrigerant circulation methods, the construction of the cooling system, and the results of the cooling tests on the railway site.

著者

岩本 雅民

出版者

CRYOGENICS AND SUPERCONDUCTIVITY SOCIETY OF JAPAN

雑誌

低温工学 (ISSN:03892441)

巻号頁・発行日

vol.34, no.9, pp.438-446, 1999-09-25 (Released:2010-02-26)

参考文献数

45

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This paper discusses biomagnetic effects and their possible applications that are unfamiliar to cryogenic and superconducting engineers. Biomagnetism is exotic applied magnetics and a transdisciplinary research target. There are two types of research methodology, physical and epidemiological. They are quite different. Both methodologies should be harmonized. The author proposes how to work in this transdisciplinary field. Finally, suggestions of guidelines for studing exotic phenomena are presented.

著者

成瀬 雅人 安藤 友彦 久保田 立記 桑田 正博 田井野 徹 明連 広昭

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.3, pp.174-180, 2019-05-20 (Released:2019-07-02)

参考文献数

37

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This paper reports how the superconducting micro-resonators work as high-sensitivity photon detectors, from millimeter-wave signals to high-energy particles. The resonators are called microwave kinetic inductance detectors and are suitable for use in a large format array. The resonators are easily fabricated applying a few photolithographic processes, and the resonator yield is more than 90%. Hundreds of superconducting resonators can be biased with a single readout line, enabling them to be read out together with frequency multiplexing. We introduce the recent progress of scientific projects relying on this technique, and summarize our results for millimeter-wave astronomy and a high-energy particle detection system. The device was made using epitaxial aluminum on a silicon wafer and its noise was as low as the background limit, approximately 6 × 10−18 W/Hz1/2 in the millimeter-wave range. For high-energy particle detection, we investigated two materials: niobium and a hightemperature superconductor, YBa2Cu3O7-δ. The niobium-based device detected the alpha line (5.4 MeV) events. The pulse decay time was approximately 5 μs and energy resolution was approximately 1 MeV.

著者

村上 正秀

出版者

CRYOGENICS AND SUPERCONDUCTIVITY SOCIETY OF JAPAN

雑誌

低温工学 (ISSN:03892441)

巻号頁・発行日

vol.17, no.2, pp.65-75, 1982-04-25 (Released:2010-02-26)

参考文献数

28

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Considerable astronomical interest has been directed towards the infrared observations in space using cooled telescopes. The design needs the use of advanced technology in many areas, especially in cryogenic.Observations in the infrared from the space environment are free from the absorption and emission by the earth's atmosphere. Telescopes and detectors cooled to a temperature near to absolute zero improve the sensitivity tremendously, because of reduction of the background noise.The use of liquid helium is essential to achieving such temperature level. Superfluid helium may be the best coolant for this purpose, owing to its excellent heat transport capability. On the other hand, several potential difficulties have been pointed out with respect to the containment of superfluid helium in tanks on board. One of such difficulties was the phase separation between vapor and liquid under zero-gravity condition. Now, it seems that this is solved by the use of the porous plug or the active phase separator.More than five space infrared missions have been planned to be launchned in the 80's. Some are presently in preparation and others are under consideration. These missions are expected to reveal stellar and planetary formation in clouds of gas and dust. The dust radiates primarily in the infrared and obscures shorter wavelengths such as the visible radiation. The Galaxy and several external galaxies are important objects which can be well studied in the infrared.We are also proposing an infrared telescope on board a Spacelab (IRTS). Relating fundamental studies and preliminary design consideration are under way.These all missions are ambitious projects and give a challenge to cryogenic physicists and engineers.

著者

橋本 巍洲

出版者

CRYOGENICS AND SUPERCONDUCTIVITY SOCIETY OF JAPAN

雑誌

低温工学 (ISSN:03892441)

巻号頁・発行日

vol.16, no.3, pp.118-130, 1981-07-05 (Released:2010-02-26)

参考文献数

15

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Recently, in order to actualize the magnetic refrigerator in the high temperature region from 4K to room temperature, several investigators in Japan and USA have studied the problem of the magnetic refrigerants, the refrigeration cycles and the new type of magnetic refrigerators. In this review successive to the previous one by Ohtsuka the current works of those are introduced.This paper consists of the following four parts:1) First, in order to make clear the direction of the investigation for the magnetic refrigerator, operations and physical charactor of the magnetic refrigerator by Brown are discussed precisely and it is pointed out that investigations on the magnetic refrigerant, heat exchange between the regenerator and refrigerant, and the thermal analysis of the fundamental magnetic refrigeration cycle are important.2) Next, current investigations on two types of magnetic refrigerants, which have the large applied magnetic field dependence of the magnetic entropy change caused by its considerable increase of internal field near Tc and the rotation of the large magnetic anisotropic substance in the magnetic field, are cited and the origin of these phenomena is explained physically.3) Then, we describe the investigations of heat exchange between the magnetic substance and heat transfer gas and of the thermal analysis of the refrigeration cycle.4) Last, for examples of new types of magnetic refrigerators, rotational-cooling magnetic refrigerator by Barclay and regenerative magnetic expander (RME) by Barclay and Steyert are introduced.

著者

米満 博夫

出版者

CRYOGENICS AND SUPERCONDUCTIVITY SOCIETY OF JAPAN

雑誌

低温工学 (ISSN:03892441)

巻号頁・発行日

vol.4, no.6, pp.247-264, 1969-12-25 (Released:2010-02-26)

参考文献数

15

被引用文献数

1 1

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This paper reviews supercritical helium gas cooling methods. The thermal transport properties of supercritical helium near 4.2°K are collected.Cryogenic helium pump or bellow pump for forced supercritical circulation is adequate to the laboratory-scale cooling system.The superconducting composite configurations with hollow conductors are used for supercritical channel forced cooling.

出版者

CRYOGENICS AND SUPERCONDUCTIVITY SOCIETY OF JAPAN

雑誌

低温工学 (ISSN:03892441)

巻号頁・発行日

vol.16, no.5, pp.259-262, 1981-11-15 (Released:2010-02-26)

著者

松本 尚徳

出版者

CRYOGENICS AND SUPERCONDUCTIVITY SOCIETY OF JAPAN

雑誌

低温工学 (ISSN:03892441)

巻号頁・発行日

vol.19, no.1, pp.35-42, 1984-03-10 (Released:2010-02-26)

参考文献数

8

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Cold Air Products Company, Ltd. (CAP) was established in May, 1975, in order to produce Liquid Oxygen, Liquid Nitrogen and Liquid Argon utilizing the cold of LNG (-160°C) imported by Osaka Gas Company.The utilization of LNG cold reduces greatly the electric power comsumption as compared with conventional processes. This feature will contribute to the savings in energy and natural resources which is a world wide requirement.In this report, the utilization of LNG cold for air separation plants is described.

著者

山田 一成 大関 和貴 須田 健嗣

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.4, pp.201-208, 2021 (Released:2021-07-20)

参考文献数

18

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A helium cryogenics system for the superconducting heavy-ion linear accelerator (SRILAC) has been introduced at the RIKEN Nishina Center. The SRILAC contains a total of 10 superconducting quarter-wave-length resonators made of pure niobium materials installed in 3 cryomodules; which realizes the beam energy upgrade of the existing room-temperature linear accelerator. The refrigerator, a HELIAL MF manufactured by Air Liquide, has successfully accomplished a cooling capacity of about 730 W and a sufficient helium pressure stability with a fluctuation less than ±0.4 kPa. The cryogenic system started operation in October 2019, and the SRILAC has been supplying beams to experiments since June 2020, along with a stable operation of the cryogenics system. This article provides an overview of the cryomodule and the helium cryogenics system as well as the operational status of the helium cryogenics system.