Atomic hydrogen beam characterization for the Project 8 neutrino mass experiment

There have been significant gains in characterizing neutrino properties in recent decades, however the absolute neutrino mass scale continues to be elusive. The Project 8 experiment seeks to probe this property directly via kinematic analysis of atomic tritium single beta decay, using the cyclotron radiation emission spectroscopy (CRES) technique. CRES employs a frequency-based approach to measure the differential tritium beta decay spectrum in the endpoint region, where the spectral shape is most sensitive to distortions from a finite, non-zero neutrino mass. A vital component to Project 8's neutrino mass measurement with a design sensitivity of 40 meV, is the use of atomic tritium. As a first step towards achieving this goal, an atomic hydrogen test stand has been developed. Atomic hydrogen beam characterization from recent measurements with high flows, more than an order of magnitude higher than those achieved in similar previously-published setups, will be presented here.