PURPOSE: To obtain a current lead which can avoid the burnout of a low temperature side lead due to quench of oxide superconductor and continue to supply a current to a superconducting coil, whose lead has little permeated heat, and simple constitution.
CONSTITUTION: A current lead 13 electrically connects a superconducting coil 1 accommodated in a vacuum heat insulation vessel 2 and kept at a very low temperature, with an external power supply. A high temperature side lead 4 is connected in series with a low temperature side lead 5, in the current lead 13. Stainless material as the low thermal conductivity metal is used for a hollow pipe surrounding oxide superconductor 9 of the low temperature side lead, and turned into bypass conductor 17 connected in parallel with oxide superconductor. Since the thermal conductivity is low, permeating heat is usually reduced. When quench is generated in the oxide superconductor 9, the current in the oxide superconductor flows through the bypass conductor 17, and the heat generation of the oxide superconductor 9 is restrained, so that burnout is prevented.
KUMAGAI TAKEO
UEDA KAZUO
ITO IKUO
KAMIIDE TOSHIO
