An Overview of the $^6$He CRES Experiment

The $^6{\rm He}$ CRES experiment at the University of Washington CENPA aims to precisely measure the Fierz coefficient $b_{fierz}$ which parameterizes a distortion of the beta-decay spectrum that is proportional to $m/E$, the mass divided by the energy of the beta-decay electron. A measurement of $b_{fierz}$ with a $10^{-3}$ uncertainty would be competitive with current LHC measurements. The decay of $^6{\rm He}$ has a large endpoint ($Q(^6{\rm He})\approx 3.5\,MeV$) which allows for the $m/E$ distortion to vary by about a factor of 7 over the spectrum and therefore leads to high sensitivity to $b_{fierz}$. Using Cyclotron Radiation Emission Spectroscopy (CRES) (a technique demonstrated by the Project 8 collaboration) the $^6{\rm He}$ CRES experiment based at the University of Washington CENPA will have high energy resolution and be shielded from systematics that affect traditional means of electron spectroscopy. We expect to have an event rate of $\approx 1 \,{\rm event} /{\rm ms}$ and need $\sim 10^8$ events for a $10^{-3}$ measurement of $b_{fierz}$. With a few days of data we should have sufficient statistics for a competitive measurement. Hardware and software progress towards the observation of our first CRES event will be presented.