Characteristic Analysis and Design of the Heater Triggered Switch for High-Tc Power Supply in Various Helium Conditions

Abstract

This paper presents experimental results and characteristic analysis of a high-Tc heater-triggered switch using a coated conductor (CC) in various low operational temperatures. A high temperature superconducting (HTS) power supply has been studied only focusing on proving the operational concept rather than applying to real superconducting magnet load. A HTS insert coil that can be installed in a low temperature superconducting (LTS) magnet has been proposed and researched to generate higher magnetic field for NMR. Since the CC could be an attractive option for the HTS insert coil, it is important to research about characteristics of the heater-triggered switch employing the CC in the low temperature. The HTS power supply consists of the two switches and one of key design parameters is to make a timing sequential chart. We investigated a quench and recovery time of the switch with respect to a heater current. A heater test in a gas helium condition was also performed and compared with the result in a liquid helium condition. From these tests, a basic data of the heater-triggered switch for optimal design of the HTS power supply was obtained; correlations among the heater current, a state and temperature of cryogen, and the quench and recovery time.