Patent ID: 7161777
Filing Date: 2007-01-09
Classification: H02H,Y02E

Abstract:
1. A superconducting magnet system with a quench protection circuit, comprising: a superconducting magnet having a superconducting coil; a persistent current switch connected in parallel with the superconducting coil to cause a persistent electric current to flow through the superconducting coil; and first and second quench protection circuits connected in parallel with the superconducting coil and the persistent current switch, respectively; wherein the first quench protection circuit comprises anti-parallel diodes and a parallelly connected resistive heater and a shunt resistor, and the resistive heater and the shunt resistor are each connected in series with the diodes; wherein the second quench protection circuit has a diode connected in parallel with the persistent current switch; wherein the shunt resistor and the resistive heater protect the superconducting coil in the event of a quench, and the resistive heater has a function of heating adjoining superconducting coil; and wherein a turn-on voltage of the diode in the second quench protection circuit is lower than those of the diodes in the first quench protection circuit.