Simulation of BeEST Photopeak Calibration

The Beryllium Electron Capture in Superconducting Tunnel Junctions (BeEST) experiment leverages Superconducting Tunnel Junction (STJ) sensors to investigate physics beyond the Standard Model, specifically looking at the recoil spectroscopy of the electron capture decay of ⁷Be to ⁷Li. Throughout the experiment, a pulsed UV laser is used to calibrate the STJ sensors; however, during Phase-III of the experiment, a systematic calibration discrepancy was observed within the various detectors caused by crosstalk and laser intensity variation. In Phase-IV these factors will be significantly mitigated by improving the experimental design with individual ground wires for each STJ pixel and the use of a more stable UV laser. This talk focuses on exploring the residual calibration artifacts of Phase III using a laser simulation approach and provides an approach to search for similar effects in Phase IV of the BeEST experiment.