This study focuses on the detection of gravitational waves (GW) in the high frequency regime with superconducting radio frequency (SRF) cavities. Measurements in the intended frequency range O(kHz-GHz) could give possible hints to new physics beyond the standard model and insights into previously hidden early universe phenomena.
The detection principle is based on the transition between two electromagnetic eigenmodes of a SRF cavity and can be described by a direct and an indirect interaction of gravitational waves with the electromagnetic field. The indirect coupling coefficients with the cavity shell are precisely analyzed and additionally the Gertsenshtein effect governing the direct interaction is presented.
In order to improve the description of GW detection, we apply our results to a SRF cavity prototype built by the MAGO collaboration at INFN Genoa in the early 2000s. Together with FNAL the Universität Hamburg and DESY revisit research on this detector concept by characterizing its geometry and the corresponding mechanical and electromagnetic eigenmodes. Combined with numerical simulations the GW strain sensitivity is calculated in the desired frequency range.
Further improvements on the MAGO cavity prototype parameters indicate that the region of new physics is accessible.