Numerical study on quench process and protection of BES III superconducting detector magnet Original Research Article

A 3D quench simulation model was developed for the BES III magnet, which is a superconducting solenoid used in Beijing Spectrometer III (BES III) of Beijing Electron and Positron Collider II (BEPC II). The BES III magnet was inner winded with aluminum stabilized Rutherford cable and conduction-cooled with forced flow of two phase helium. Quench processes of the magnet under different protection techniques were simulated with the model. The minimum quench energy, the quench propagation velocity, the maximum temperature rise and the maximum voltage drop of the coil were analyzed. Protection capabilities of the different techniques were compared according to the simulation results, and the simulation results were compared with the experimental data. Recommendations to the protection of the detector magnets are presented.