Journal of the Korean Physical Society

pISSN 0374-4884 eISSN 1976-8524


J. Korean Phy. Soc. 2006; 49(9(6)): 268

Published online December 20, 2006

Copyright © The Korean Physical Society.

Joint Development for KSTAR CS Coil

K. Park, D. Lee, S. Kwak, W. Chung, K. P. Kim, Y. Chu, Y. M. Park, Y. K. Oh and J. S. Bak


We have developed a lap joint for KSTAR CS coils. CS coils use Nb$_{3}$Sn strand and require a heat-treatment process. Before heat-treatment of the coil, the chrome coating of the cable surface was removed, and the cable of a superconductor was compacted by 60-ton force in a stainless steel housing. After heat-treatment, the housing was removed and the cable was soldered with the copper block of the CS coil joint. We completely filled the lap joint with solder and made additional helium paths in the joint block. We manufactured full-size lap joint samples for the CS coil by this process and tested them at liquid helium temperature. The DC resistance of the joint is below 2 n$Omega $, so it satisfies the DC design requirement of KSTAR, which is 5 n$Omega $.