Feasibility study for axion searches: non-linearity investigation in Nb SRF cavities

The SQMS Physics and Sensing thrust is working toward the implementation of multiple axion search schemes to improve upon the current state-of-the-art sensitivity. The search schemes under consideration utilize either single or multiple SRF cavities in several distinct manners. This work presents the first results of multi-mode and single mode non-linearity measurements carried out on 1.3 GHz Nb SRF cavities that give insights on the fundamental behavior of these resonators as well as the feasibility of the proposed axion search schemes.