Thermal contraction of bobbin and winding for persistent current switches and their stability of current performance

We study the stability of persistent current switches (PCSs). In this study, we measured the thermal contraction coefficient of several samples of PCSs. The bobbins of the sample PCSs used in our experiments were made of several kinds of FRP, of glass fiber, high strength polyethylene (Dyneema) fiber, and cotton fiber. The thermal contraction coefficients of the bobbin and winding were measured by strain gages. It is found that the thermal contraction of the bobbins influenced the thermal contraction of the windings and also influenced the stability of current performance.