Design and characteristic analysis of active quench protection system for superconducting magnet

The detection of normal zones in the coil winding and the initiation of the proper dump sequence have been one of the most important areas in supercon ducting magnet technology. An active protection scheme is also needed for p rotection of high-Tc superconducting magnet. In this paper, the theoretical process to derive the dump sequence has been investigated in magnetically coupled adiabatic magnet system. The magnet terminal voltage, maximum tempe rature in the quench, initiation point and resistance rise in the winding a re calculated numerically with respect to various input variables. The expe rimental system is comprised of 3-nested solenoid cells, data acquisition d evice, external circuit breakers and dump resistor. Quench behavior of the magnet (e.g., the temperature profile and the voltage signals) was measured as a function of operation current, dump resistance, etc. From these resul ts, theoretical predictions were found to coincide with the experimental ob servations.