Speaker
Description
Precise in-situ magnetometry is a crucial tool for achieving 40-meV sensitivity to the electron-neutrino-weighted mass sum from the tritium beta decay electron energy spectrum that the Project 8 collaboration has proposed to measure via its novel cyclotron radiation emission spectroscopy (CRES) technique. Magnetic field uniformity over the fiducial cryogenic volume is required at the 0.1 ppm level, for which high-precision magnetometry is vital. We describe a system for performing helium-3 nuclear magnetic resonance (NMR) in a modified resonant cavity based detector compatible with both magnetometry and the CRES science signal. Outside the detection volume, helium-3 will be spin-polarized to a fraction approaching unity via metastability exchange optical pumping (MEOP) at room temperature. It will then be fed into the cryogenic modified cavity, and used to perform in-situ magnetometry. A prototype apparatus is under construction at the University of Washington.