Quench Current Measurement for Multi-Sectioned Superconducting Solenoid Coil

The technique of subdivision protection is extensively applied to protect large superconducting solenoid magnets such as accelerator magnets and MRI magnets. The number of subdivision and the parameters of protection circuit are usually decided by the quench simulation results. The accurate current data during quench process is important to verify the quench simulation code and estimate the magnet performance. But not like voltage signal, the acquisition of which just needs to attach a pair of voltage taps on both side of each protection resistor, current signal is very difficult to be obtained from cryogenic environment. This paper presents an algorithm to calculate the quench current from the quench voltage measurement result. By this algorithm the temperature rise history of protection resistor is obtained simultaneously.