Analysis of the Quench Protection System of a Series Connected Hybrid Magnet

An active quench protection system is planned to safely guard the superconducting coils of a 36 T hybrid magnet during a quench. The quench circuit includes a 0.1 Omega external discharge resistor, blocking diodes, and high-current circuit breakers for isolation of the power supplies during a dump. The protection system will rely on redundant hardware encoded circuits for detection of quench voltages. A quench modeling program has been created that incorporates GANDALF as the thermal and hydraulic module. Quench simulations have been performed to model temperatures, pressures, and mass flow rates of the helium and conductor. The response of the system under a protected quench has been analysed and it is shown that the coils would be adequately protected with a quench detection voltage of 1 V. Energy and helium expulsion rates during a quench are computed to determine the capacity and configuration of the cryogenic refrigeration system during off-normal events.