Quench Voltage Analysis for a Long Superconducting Solenoids Group

A solid understanding and accurate analysis of the voltage transients in the quench process of superconducting magnets is the basis for verifying quench protection system design. This paper presents an analysis of the voltage spike that triggered a quench in a serially connected set of superconducting solenoid magnets, which are protected by a stack of cold diodes and dump resistors. The voltage development associated with the normal zone growth is analyzed. The magnets were trained close to the full design current and all the terminal voltages of the coils were captured by a specialized quench detection system. In the analyses described in this paper, the different stages of the voltage transient development will be detailed. Comparisons of simulations and the training results are provided to substantiate the mechanism of the quench voltage behavior in this passive protection scheme.