A method for interplay analysis between quench protection and quench characteristics of close-wound superconducting magnet

Highlights: • A systematic way to determine the quench protection parameters (dump resistor ad quench voltage threshold) considering the coil quench is proposed. • The interplay between quench protection system and coil quench characteristics (voltage and temperature) is analyzed in detail. • The transverse heat conduction in the coilcross sectionis realized with the THEA code. -- Abstract: The quench protection of the close-wound superconducting magnet is a key factor during the design process, especially when used on the particle therapy gantry system. Therefore, the interplay between quench protection and coil quench needs to be considered from the earliest stage of the design. For this purpose, a method using Cryosoft code is presented in this paper. Based on the quench protection electric circuit, the current and voltage evolution of the quench protection circuit and the temperature and normal zone evolution of the superconducting coil all can be obtained with this method. By studying the allowable action time for the quench protection associated with the operating current, the quench voltage threshold and the resistance of the dump resistor are determined, which is 0.4 V and 0.3 Ω. The differences of the voltage evolutions obtained with different kinds of dump resistor connections are also studied. The results show that it is better to have the dump resistor directly connected to the coil than with a switch. The advantage of this method is its integration and comprehensiveness and can be used in the design procedure of different kinds of magnets.