Note: Design and resonant condition measurement of the mushroom-shaped Al test cavity for critical magnetic field evaluation of superconducting thin-film sample

We designed a mushroom-shaped Al test cavity for measurement of the critical magnetic field at a radio frequency microwave with a frequency of 5.2 GHz. The characteristics of the Al test cavity are characterized toward the evaluation of the superconducting multilayer thin films under high power radio frequency microwaves at cryogenic temperatures by the Nb-based cavity. We evaluated a target resonant frequency, the separations of neighboring modes, and the electromagnetic field distribution of the target mode. The calculated frequency change was in good agreement with that obtained experimentally. Published by AIP Publishing.