Development of a Detachable Current Feeder Terminal for Direct Excitation of Magnetically Levitated High-temperature Superconducting Coils

Abstract

An internal coil device, Mini-RT, is being constructed for high-beta plasma confinement studies by means of the magnetic field generated using a magnetically levitated high-temperature superconducting (HTS) coil. In the Mini-RT, the coil is directly charged by a DC power supply through removable current feeder terminals, and therefore, the generation of joules at the terminals as the result of contact resistance must be suppressed in order to reduce heat propagation to the HTS coil. Three different terminals with contact springs were trial manufactured and examined under room and liquid nitrogen temperatures. The contact resistances at both temperatures depended on the terminals and the spring materials. We selected the best terminals for Mini-RT, and confirmed that the differences between the design values and the results were less than 20 percent.