Monitor Detector for Relative Normalization with $^{\mathrm{6}}$He-CRES Experiment

The $^{\mathrm{6}}$He Cyclotron Radiation Emission Spectroscopy (CRES) experiment at the University of Washington aims to precisely measure the Fierz coefficient by analyzing the cyclotron radiation of beta-decay electrons in a magnetic trap. This experiment takes data over a finite bandwidth which does not cover the entire beta spectrum. In order to \textit{stitch together} each piece of the spectrum, we use a silicon beta detector. We are testing the stability of a Passivated Implanted Planar Silicon (PIPS) detector and digitizer to be used to monitor beta activity. Initial tests were done with an $^{\mathrm{241}}$Am alpha source, cooled to -10 C to optimize resolution. With this system, we've achieved stability on the level of 10$^{\mathrm{-4}}$ as shown via an Allan deviation analysis. Our next measurements will be taken with a $^{\mathrm{90}}$Sr beta source whose energy spectrum more closely resembles that of $^{\mathrm{6}}$He.