Performance improvment of RF superconducting cavity

To improve the acceleration properties of the niobium cavities and niobium-sputtered copper cavities, studies are carried out. For niobium-sputtered copper cavities, by adding a layer of NbN between the copper and niobium, the transition temperature of the superconducting film can be increased so that the superconducting properties can be improved. Analysis shows that the accelerating gradient can be improved by preparing SIS multilayers on the surface of the superconducting cavities.