TY - JOUR
T1 - Study of HTS bulk current lead with metal alloy impregnation under vacuum
AU - Tsuzuki, K.
AU - Sugyo, D.
AU - Kimura, Y.
AU - Izumi, M.
AU - Sakai, N.
AU - Miki, M.
AU - Hayakawa, H.
N1 - Funding Information:
Manuscript received August 19, 2008. First published June 23, 2009; current version published July 15, 2009. This work was supported in part by Sasakawa Scientific Research Grant from The Japan Science Society and Japan Railway Construction, Transport and Technology Agency (JRTT). K. Tsuzuki, D. Sugyo, Y. Kimura, and M. Izumi are with Tokyo University of Marine Science and Technology, 2-1-6 Etchu-jima, Koto-ku, Tokyo, Japan (e-mail: m084026@kaiyodai.ac.jp). N. Sakai is with ISTEC-SRL, Shinonome, Koto-ku, Tokyo 135-0062, Japan. M. Miki and H. Hayakawa are with Kitano Seiki Co. Ltd., Ota-ku, Tokyo 143-0024, Japan. Digital Object Identifier 10.1109/TASC.2009.2018449 Fig. 1. Schematic view of the sample of a Bulk HTS for current lead. They are Gd-Ba-Cu-O melt-growth crystals synthesized by Nippon Steel Co. Ltd.
PY - 2009/6
Y1 - 2009/6
N2 - The high-temperature superconductor (HTS) bulk current lead (BCL) is a crucial device for a large number of currert applications such as the propulsion motor with HTS winding. The coexistence of low thermal conductivity and superconductivity enables us to shrink the dimension of the power system. To use the BCL effectively, we have to optimize the temperature gradient across the BCL along its length. For this purpose, it is essential to obtain a better physical contact between the bulk HTS surface and Cu terminal leads. There are, however, many pores at the surface of the bulk which cause difficulties for joining. In order to solve this problem, we focused on an impregnation technique which has been known to improve strength and thermal characteristics of the bulk HTS itself by using epoxy. We succeeded to fill in the pores of the bulk HTS surface with a metal alloy impregnation Following this method, we made the BCL of Gd-Ba-Cu-O by ourselves. By adopting a suitable cooling with a GM cryocooler the resistance of the BCL was 0.8 across the BCL under a current flow of 300 A, considering one end was at 40 K and the other one was at 70 K. The properties of the present BCL are satisfactory for connecting a coil in large current power systems such as superconducting motors.
AB - The high-temperature superconductor (HTS) bulk current lead (BCL) is a crucial device for a large number of currert applications such as the propulsion motor with HTS winding. The coexistence of low thermal conductivity and superconductivity enables us to shrink the dimension of the power system. To use the BCL effectively, we have to optimize the temperature gradient across the BCL along its length. For this purpose, it is essential to obtain a better physical contact between the bulk HTS surface and Cu terminal leads. There are, however, many pores at the surface of the bulk which cause difficulties for joining. In order to solve this problem, we focused on an impregnation technique which has been known to improve strength and thermal characteristics of the bulk HTS itself by using epoxy. We succeeded to fill in the pores of the bulk HTS surface with a metal alloy impregnation Following this method, we made the BCL of Gd-Ba-Cu-O by ourselves. By adopting a suitable cooling with a GM cryocooler the resistance of the BCL was 0.8 across the BCL under a current flow of 300 A, considering one end was at 40 K and the other one was at 70 K. The properties of the present BCL are satisfactory for connecting a coil in large current power systems such as superconducting motors.
KW - Gd-Ba-Cu-O
KW - High-T superconductor
KW - Melt-growth bulk crystal
KW - Superconducting coils
KW - Superconducting current leads
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U2 - 10.1109/TASC.2009.2018449
DO - 10.1109/TASC.2009.2018449
M3 - Article
AN - SCOPUS:68649105663
SN - 1051-8223
VL - 19
SP - 2214
EP - 2217
JO - IEEE Transactions on Applied Superconductivity
JF - IEEE Transactions on Applied Superconductivity
IS - 3
M1 - 5109557
ER -