Optimizing Beamline Geometry for Enhanced SNR in BECOLA’s Fluorescence Spectroscopy

Nuclear Physics has undergone rapid advances thanks to new accelerator facilities being built. The Facility for Rare Isotope Beams (FRIB) at Michigan State University is a world-leading nuclear physics research laboratory. At FRIB, the BEam COoling and LAser spectroscopy (BECOLA) group performs high-resolution optical measurements to provide model-independent nuclear data on the radius of radioactive rare isotopes. Such data is required to benchmark state-of-the-art theoretical calculations. To produce high-quality data, resolution and sensitivity are crucial. Increasing Signal to Noise Ratio (SNR) is key for the best experimental results. At BECOLA laser-resonant fluorescence measurements are performed, where large background due to scattered laser light hinders to achieve high SNR. We studied the time-dependent distribution of scattered laser light or photons in the BECOLA photon detection chamber. This work aims at the development of a new approach to fluorescence detection by eliminating background in a time-dependent manner. Simulations have been performed using the optical engineering software, FRED, to maximize the SNR by adjusting the geometry of the photon detection region. Optimized geometry of the detection region will be discussed. The improved SNR will open the possibility of measuring more exotic nuclei with the fluorescence technique.