He-CRES: Apparatus Upgrades*

The ⁶He-CRES experiment aims to precisely measure the beta spectra of ${}^{19} extrm{Ne}$ and ${}^6 extrm{He}$ using Cyclotron Radiation Emission Spectroscopy (CRES). The technique is based on determining the beta energy from measurements of the cyclotron frequency. In order to minimize sensitivity to frequency-dependent RF response, the experiment uses the ratio of these spectra. The ratio exhibits enhanced sensitivity to chirality-flipping currents because the latter have opposite signs for positron versus electron emission. First results of broadband CRES have been reportedfootnote{https://doi.org/10.48550/arXiv.2209.02870}. 

Since that data was collected, improvements to the apparatus were made. These include changes to the RF systems to improve the frequency dependence of noise and signal. Various other improvements to the source, vacuum system, and data collection were also made. These refinements and their impacts for planned CRES measurements will be presented.