Variable temperature apparatus using a thermal conductivity measurement technique for the determination of superconducting ac power loss

A variable temperature apparatus is described which uses a thermal conductivity measurement technique for the determination of superconducting ac power loss. The technique consists of measuring the increase in temperature of a thermally isolated sample carrying an alternating current. Accurate measurements over a relatively large temperature range are possible. Loss data on a 13 cm long, single filament NbTi superconductor are presented at various temperatures and currents.