SALER@FRIB: Nuclear Recoil Spectroscopy for BSM Physics

The Superconducting Array for Low Energy Radiation (SALER) at FRIB is a new experiment using superconducting tunnel junction (STJ) radiation detectors to make the first nuclear recoil measurements of short-lived isotopes at the eV scale. SALER is initially targeting exotic scalar and tensor current contributions to the weak force at the TeV scale, starting from the mirror nuclei ¹¹C and ¹⁹Ne. In these cases, the recoil encodes information about the ratio between Fermi and Gamow-Teller decay modes allowing for an indirect measurement of V_ud. Over the past 2 years, we have accepted the SALER equipment at FRIB and performed the offline commissioning of the first STJ array in the ReA3 experimental hall, with planned online (stable) beam commissioning in 2026. In this talk, we present on the newest results from the offline performance of SALER as well as progress towards integration with existing systems at FRIB.