Hybrid Cavities for Axion Detectors
Hybrid cavities, cavities with a layer of superconductor applied on top of the OFHC copper, are studied. The quality factor of a single thin layer and of a multilayer superconductor/insulator stack are estimated. The results for these thin-film coatings are not good. However, if the superconductor (either multilayer or single layer) were separated from the copper by a thick dielectric spacer, one that is a fraction of the wavelength at the cavity resonant frequency, extremely high quality factors could be obtained.
KeywordsAxion Dark matter Haloscope Superconducting Thin film Multilayer Anomalous skin depth Quality factor Type-II Fluxoids London model Drude model
This research was supported by DOE grant DE-SC0010296.
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