Speaker
Description
Project 8 has pioneered the technique of cyclotron radiation emission spectroscopy (CRES) to probe the neutrino mass. In CRES, a beta decay electron in a magnetic field produces cyclotron radiation that can be detected and used to recover the electron energy; the neutrino mass can be extracted near the endpoint of the electron spectrum. Molecular tritium, the beta source used in previous experiments, suffers from endpoint smearing due to rovibrational modes, driving an effort to develop an atomic tritium source. Project 8 will require 10$^{15}$ atoms per second at $~$5 mK to reach a neutrino mass sensitivity of 40 meV. To characterize the atom beam flux from 2000 K to 5 mK, we are developing several characterization tools. One otherwise-valuable tool, a quadrupole mass analyzer that is sensitive to low masses (Hiden DLS-20), will have limited utility in the strong-magnetic-field environment of the magnetic evaporative cooling beamline. We describe here our work developing a wire detector that detects atoms via the change to its resistance when atoms recombine into molecules on its surface. We also describe our work characterizing the beam using the wire detector, quadrupole mass analyzer, and a rotating chopper to periodically interrupt the beam.