Performance test of a persistent current switch insulated with cotton tape

In order to design thermally trigger controlled persistent current switches (PCSs) for superconducting magnet systems, it is very important to know information of adiabatic method and condition to obtain designed resistance and characteristics. In this work, the authors used cotton tape as a thermal insulator and calculated averaged thermal conductivity of it around 10 K on the assumption that the adiabatic structure of PCS is the shape of a pipe. The result of about 0.29 W/m/spl middot/K was verified a reasonable value by computer simulations and estimation of test PCS, which was designed and manufactured with different dimensional parameters. The experimental results of test PCS were in good agreement with the calculated results.