A Proposal of Multi-stage current lead for reduction of heat leak

Abstract

AbstractThe reduction of the heat leak from the terminal is one of important issues to realize the applications of superconductivity, and the Peltier current lead (PCL) has been developed until now. The reduction of the PCL as compared with the usual copper lead is almost 40%, however the reduction of heat leak is still required to improve the total efficiency of the superconducting system. Therefore, we estimate the performance of the multi-stage current lead (MCL) and propose a gas-cooled MCL in this paper. The principle of the MCL depends on that the COP of the refrigerator is higher in a high temperature, and the resistivity of the copper is lower at lower temperature. But MCL was not tested experimentally until now. Fortunately, the COP of the various kinds of the refrigerators has been improved recently. The preliminary estimation of the MCL and the gas-cooled MCL shows that the saving power is high as 50% to 70%, depending of the assumption of the refrigerator COP. Therefore, it is a good time to examine the concept of MCL experimentally