Status of the Project 8 Detector Prototype

The average mass of the 3 neutrino mass eigenstates has been bound by oscillation experiments and by direct mass measurements to lie in the range $0.02{\rm\ eV} \leq m_\nu \leq 2{\rm\ eV}$. Nonetheless, only the upper decade of this parameter space will be accessible to the most sensitive experiment presently under construction, KATRIN. The Project 8 collaboration has been involved in the development of technology in the form of a prototype detector which may offer sensitivity to neutrino masses over the entire allowed parameter space. The key to this technology is a direct, non-integrated measurement of the energy spectrum of $\beta$ decay electrons very near the endpoint of $^3{\rm H}$ decay by probing the cyclotron frequency of those electrons as they move in a strong background magnetic field. The current generation of the prototype detector is expected to reach 1\,ppm resolution of the cyclotron frequency of the electron. Recent progress and results from the detector prototype will be discussed. This research is supported by DOE under grant DE-FG02-97ER41020.