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

門奈 五兵

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.8, no.3, pp.118-119, 1973-07-15 (Released:2010-02-26)

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

森 大吉郎

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.17, no.4, pp.215-221, 1982-08-30 (Released:2010-02-26)

---

Noticing the excellent performance of liquid hydrogen-liquid oxygen (LH2/LOX) propulsion system, the Institute of Space & Astronautical Science (ISAS) has started the preliminary study in 1971, and since 1975, full-scale development program of the engine, which has the capability of 7ton thrust in vacuum, has been undertaken.Various development tests of the engine components (thrust chamber, turbopump, gas-generator and turbine spinner etc.) have been conducted at the Noshiro Testing Center of ISAS.Integration tests of the stage, comprised of thrust chamber, turbopump, gas-generator and tank, have been carried out from September through December in 1981 with fairy good results.In the present paper, major features and characteristics of this 7ton engine are summarized.

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

---

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

田辺 圭一

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.47, no.7, pp.436-437, 2012-07-25 (Released:2012-09-12)

著者

大塚 泰一郎

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.35, no.6, pp.279-284, 2000-06-25 (Released:2010-02-26)

参考文献数

7

---

As described in the previous chapters, experiments following the introduction of the London theory revealed a few serious problems which could not be explained by the theory. Examples are transition to the normal state when the magnetic field is applied parallel to the surface of a superconducting film and the dependence of the penetration depth on the addition of impurities. The latter problem was resolved by Pippard through the introduction of the coherence length as described in the previous chapter. A serious problem which remained unresolved was the surface energy at the boundary of the superconducting and normal phases in the intermediate state of Type 1 superconductors. The stability of the intermediate state observed in experiments requires the boundary energy to be positive, which can not be explained by the London theory. In the next few chapters, the phenomological theory by Ginzburg and Landau, which not only resolved these problems but also led to the prediction of Type 2 superconductors, will be described.

著者

山田 豊 長谷部 次教 柳谷 知之 直原 和哲 石塚 正之 安原 征治 石原 守

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.28, no.2, pp.86-91, 1993-02-25 (Released:2010-02-26)

参考文献数

12

被引用文献数

3 7

---

Superconducting properties of Bi-Pb-Sr-Ca-Cu-O superconducting bulk fabricated by intermediate cold isostatic pressing (C. I. P.) process have been investigated, and heat leakage per a bulk lead pair from 77K to 4.2K has been evaluated. The critical current density of the tubular bulk, approximately inner diameter 10-30mm and 200mm long, was indicated more than 1, 000A/cm2 at 77K under self-magnetic field, and at 4.2K was indicated as about 2, 000A/cm2 under 15T. The reasons for improvement of Jc are the formation of high Tc single phase and highly aligned microstructure of the bulk. The heat leakage per a pair of the bulk leads from 77K to 4.2K has been measured to be 0.16W at DC 800A and considered to be less than one-tenth of that of 800A-class conventional gas-cooled current leads.

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 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

高橋 勝國 斎藤 敏雄 柳島 淑隆 神谷 祥二 老固 潔一 岩田 章 増井 喜健

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.15, no.2, pp.97-110, 1980-05-25 (Released:2010-02-26)

参考文献数

18

被引用文献数

3

---

This paper presents the results of a study on the pressure drop and the film boiling heat transfer for a two-phase flow of hydrogen in a horizontal tube.Experiments were made on two types of tube; two pieces of vacuum insulated straight tubes of 4m long, inside diameters of which are 18.4 and 23.9mm, respectively; Anuninsulated tube of 8m long with 90 degree bends at two locations, inside diameter of which is 12.3mm.Experimental conditions were as follows; Flow rate (l/min.); 5 to 50 Vapor quality; 0.01 to 0.90 Pressure (bar); 1.4 to 5.8 Conclusions obtained from the experiments are summarized below.1) The frictional pressure drop of two-phase flow of hydrogen for a straight tube is well related to a modified Lockhart-Martinelli (L-M) curve, that is, L-M pressure ratio parameter, φl multiplied by 0.8, for both adiabatic and diabatic conditions. More than 90% of data fell within the scatter band of ±20% from the modified L-M curve.The pressure drop for a bend was also correlated by using parameters analogically introduced from L-M parameters for a straight tube.2) As for the heat transfer by forced-convection film boiling, the following relationship was established based on the method proposed by Ellerbrock.(Nuf/Nufm)⋅Bo-0.4=9.46Xtt-0.131More than 90% of data obtained were in agreement with the the expression shown above with no more than ±20% error.In this study, it was known that the heat transfer for two-phase flow of nitrogen as well as hydrogen follow Ellerbrock's theory.

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.