Field operation and cooling test of high Tc coil made of Bi-based pancake coil were carried out. By the measurement of critical current distribution inside the high Tc coil, we found that the critical current of the edge pancake coil is lower than that of the center pancake coil. This result is explained quantitatively in consideration of field and field angle dependence of critical current for the tape-shaped conductor and field distribution inside the coil. Magnet system assembled GM-refrigerator, high Tc current lead and the high Tc coil was tested. As a result, it was found that thermal load into the coil was low and field operation up to 90% of critical current of the high Tc coil was stable.

Coil noise

Bismuth

Coil tap

10.2221/jcsj.29.65

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Citations (2)

Effects of Thermal Conductance in the Cooling Stage of a 4K-GM Refrigerator on Refrigeration Capacity

Advances in cryogenic engineering (1998)

Takashi Inaguchi Masanori Nagao Kouki Naka Hideto Yoshimura

Cooling capacity

10.1007/978-1-4757-9047-4_228

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Citations (4)

Development of a 2W Class 4 K Gifford- McMahon Cycle Cryocooler

Springer eBooks (1997)

Takashi Inaguchi Masashi Nagao Kouki Naka Hideto Yoshimura

Cooling capacity

10.1007/978-1-4615-5869-9_70

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Citations (7)

A conceptual design of a superconducting magnet for MAGLEV using a Bi-based high-Tc tape

IEEE Transactions on Applied Superconductivity (1995)

Shoichi Yokoyama K. Shimohata Takashi Inaguchi Toshie Takeuchi T. Kim

A conceptual design of a superconducting magnet for MAGLEV using a Bi-based high-Tc superconducting tape ((BiPb)/sub 2/Sr/sub 2/Ca/sub 2/Cu/sub 3/O/sub 8/-Ag) is studied. In this study, the structure of conductor and coil, AC loss, stability, current lead, persistent current switch, cryostat structure and cooling system are estimated. The characteristics of the design are as follows: (1) the superconducting coil is cooled by a refrigerator at 20 K and is operated by persistent mode; (2) the coil is constructed by 6 pieces of double pancake coils, and each pancake coil is graded by changing conductor size; (3) the temperature rise of the coil is about 2 K due to AC loss; and (4) the superconducting stability is very high.< >

Cryostat

Maglev

10.1109/77.402624

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Citations (9)

Design of a large current-type fault current limiter with YBCO films

Physica C Superconductivity (2002)

K. Shimohata Syoichi Yokoyama Takashi Inaguchi S. Nakamura Yasuo Ozawa

Fault current limiter

Limiter

Temperature Gradient

10.1016/s0921-4534(02)01088-2

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Citations (32)

Experimental and numerical study on vacuum arc for designing electrodes of vacuum interrupters

IET conference proceedings. (2024)

Toshihiko Takematsu Yuta Sagara Takashi Inaguchi Takayasu Fujino

Vacuum arc

Electric arc

10.1049/icp.2024.0757

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Citations (0)

Cryocooler with Magnetic Regenerator Materials Review Article. Development of Rare Earth-Ruthenium Intermetallic Compounds for Use as Regenerator Materials.

TEION KOGAKU (Journal of Cryogenics and Superconductivity Society of Japan) (1996)

Y. Hanaue Kouichi Ishiyama Etsuji Kimura Takuo Takeshita Masashi Nagao

Rare earth-ruthenium intermetallic compounds have been developed for ues as regenerator materials in helium liquefaction Gifford-McMahon refrigerators. These compounds show characteristically lower magnetic transition temperatures than other rare earth intermetallic compounds. The refrigeration capacity of GM refrigerators has been remarkably improved by the use of Ho1·5Er1·5Ru spheres as regenerator materials at the temperature range below 5K. This material posseses a large heat capacity even under magnetic fields of 0.5T in such a temperature range. Spherical powders of these materials were produced by a simple method named the “low pressure jet method, ” which offers good sphericity powders with smooth surface. Nozzle clogging is a serious problem in this method, but we have overcome this problem by reducing gas elements such as oxygen, fluorine, from starting materials.

Magnetic refrigeration

10.2221/jcsj.31.156

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Citations (1)

Analysis of Transitional Change in Pressure after Quench in Superconducting Generator.

JSME International Journal Series B (1998)

Takashi Inaguchi Hideto Yoshimura Toshiki Hirao Kazuichi Suzuki Akinori Ueda

This paper describes analysis of transitional change in pressure after a quench of field windings in a superconducting generator. We constructed a calculation model by which it is possible to predict transitional changes in pressure after a quench in the helium vessel of a superconducting generator, and performed numerical calculation. To verify the calculation model, the calculated results were compared with tested results derived from the Model Rotor, and we could confirm the accuracy of the calculation model. Applying the calculation model to the 70-MW class superconducting generator, we found that the maximum pressure in the helium vessel of the 70-MW class superconducting generator reached 1.7 MPa at the quench of the maximum field current.

Superconducting electric machine

10.1299/jsmeb.41.697

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Citations (0)

Numerical Simulation of 4K GM Refrigerator

Springer eBooks (2002)

Takashi Inaguchi Masanori Nagao Kouki Naka Hideto Yoshimura

10.1007/0-306-47090-x_71

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Citations (1)