Effect of twist on wires made from i n s i t u superconductors

Abstract

The effect of twist on the transverse field hysteresis of in situ superconducting wires is assumed to result from a lowering of the axial critical current density due to anisotropy of critical current density in the material. In weak transverse magnetic fields the twist raises the hysteresis loss, while in stronger fields the twist lowers the loss. It is shown that the axial critical current density determined from hysteresis or magnetic moment measurements in a twisted wire can be lower than the value obtained from transport measurements.