Stability test of conduction-cooled LTS/HTS composite coil

Abstract

A small LTS/HTS composite coil made of NbTi/Cu and YBCO, with an inner diameter of 80 mm, an outer diameter of 88mm, a height of 50 mm, and an inductance of 5.5 μH, was designed to test its heat disturbance performance in a GM cryocooler. For comparison, a conventional LTS coil of a similar size made of NbTi/Cu wire was also tested. Transport current was applied from 50 A to 700 A at 8 K and 8.5 K, respectively. The two coils’ heat disturbance, minimum quench energy and quench propagation velocity performance were investigated and simulated. The results indicate that the LTS/HTS composite coil shows better thermal stability and is more fit for operation in conductive cryocooler systems compared to LTS coils.