Project 8 Phase II: Measuring the Tritium Beta-Decay Spectrum using Cyclotron Radiation Emission Spectroscopy*

Project 8 is a tritium endpoint neutrino mass experiment utilizing a phased program to achieve sensitivity to the range of neutrino masses allowed by the inverted mass hierarchy.  The Cyclotron Radiation Emission Spectroscopy (CRES) technique is employed to measure the differential energy spectrum of relativistic decay electrons with high precision.  A proof of principle experiment (Phase I) has measured the monoenergetic conversion electrons of a gaseous ^83mKr source using a small waveguide detector.  Phase II will extend this work to a first demonstration of the CRES technique on a continuous spectrum, measuring the tritium beta-decay spectrum near the endpoint.  Significant hardware modifications to the existing system have enhanced the radiofrequency properties and made the system compatible with the tritium source gas.  Here we present the hardware upgrades and the data analysis challenges faced during the second phase of the Project 8 experiment.