Characteristics of High Temperature Operation in a Conduction Cooled (Nb,Ti)3Sn Superconducting Magnet
Intense investigations aiming at application workable at liquid nitrogen temperature have been performed, since the discovery of high temperature superconductors with the critical temperature Tc in excess of 77.3 K. Realization of practical superconductors at high temperature like 77.3 K is expected to significantly promote industrial development. The most important superconducting properties for application are the large critical current Ic and the high critical current density Jc. Especially, the large transport current in fields is a key parameter for power application. However, there exist many crucial issues in the Jc properties of high-Tc oxide superconductors. The flux creep behavior1 is one of the difficult problems to be solved out for application at 77.3 K. Although the flux creep has been already understood through the model proposed by Anderson and Kim2 in conventional low-Tc superconductors, it did not practically influence the usage at liquid helium temperature of 4.2 K for low-Tc superconductors, because of the negligibly small effect at 4.2 K. On the contrary, the extremely large flux creep phenomenon is observed at high temperature like 77.3 K in high-Tc superconductors. Therefore, the satisfactory solution of the flux creep is inevitable to realize a superconducting magnet employing high-Tc superconducting wires, which will be operated at 77.3 K, for instance.
KeywordsSweep Rate Superconducting Magnet Liquid Helium Temperature Coil Current Heat Leak
Unable to display preview. Download preview PDF.
- 4.K. Watanabe, Y. Yamada, J. Sakuraba, F. Hata, C.K. Chong, T. Hasebe, and M. Ishihara, Proc. 8th US-Japan Workshop on High-Field Superconducting Materials, Wires and Conductors and Standard Procedures for High-Field Superconducting Wires Testing, edited by K. Yamafuji, H. Wada, D.C. Larbalestier, and M. Suenaga, Madison, p112 (1993).Google Scholar
- 5.H. Shiraki, S. Nakagawa, M. Tanaka, S. Murase, K. Noto, K. Watanabe, and Y. Muto, Proc. MRS Inter. Meeting on Adv. Mat., Tokyo, p43 (1989).Google Scholar