Superconducting RF Cavity Performance Degradation after Quenching in Static Magnetic Field
I. Terechkine1 T. Khabiboulline1 D. Sergatskov1
1Fermi National Accelerator Laboratory, Batavia, IL, USA
Performance degradation of a superconducting RF cavity after quenching in an external magnetic field was calculated using COMSOL. This degradation is due to the increased resistance of a superconducting surface with trapped magnetic flux. The amount of the trapped flux depends on the size of the normally-conducting opening that develops in the superconducting wall of a cavity during quenching. This size is found by solving time dependent problem of heat propagation in walls of RF cavities; the trapped flux can be found by making static magnetic modeling for any specific geometry that includes the quenching cavity and a source of the magnetic field. Results of simulation are compared with the data obtained in a specially designed experiment.