Multimode Resonant Cavity Designs for the Project 8 Neutrino Mass Experiment

Project 8 aims to measure the atomic tritium beta decay spectrum endpoint to determine the absolute neutrino mass scale using Cyclotron Radiation Emission Spectroscopy (CRES), with a projected sensitivity goal of 40 meV/c². Phase III of the experiment will demonstrate CRES with magnetically confined electrons in microwave resonant cavities. The cyclotron radiation combined with the axial motion of electrons in the resonant cavity will generate unique signal features that are important in event reconstruction, and the cavity resonance mode which the electron couples to determines what signal features are present. This talk will introduce a multimode resonant cavity design scheme that would involve electron coupling to multiple cavity modes. We will overview how electron event reconstruction from multiple cavity modes can outperform reconstruction from single modes.