Current Status of the SALER Experiment at FRIB

The Superconducting Array for Low Energy Radiation (SALER) is a new experiment in the ReA3 Hall at the Facility for Rare Isotope Beams (FRIB). SALER aims to measure the low-energy nuclear recoil spectrum of embedded short-lived radioisotopes using a superconducting tunnel junction (STJ) sensor array at ~30 mK to perform a wide range of BSM physics searches including fundamental tests of the weak interaction. In March 2024, we took delivery of the cryostat, electronics, and 32 of the eventual 128 STJ detectors at FRIB. In this talk, we present on the current status of the acceptance testing and initial offline characterization of SALER at FRIB using a ¹³⁷Cs source. We will also discuss the development of a fiber-coupled UV laser feedthrough for calibration and progress towards integration with existing systems at FRIB.