Superconducting Quantum Sensors for sub-keV Radiation Detection with Short-Lived Rare Isotopes

Low-energy nuclear recoil spectroscopy of short-lived rare isotopes is a powerful and unique probe in our search for physics beyond the Standard Model (BSM) using beta decay. This work has been been performed to great effect using atom and ion traps over the past several years but are now reaching the limits of EM field control and particle scattering backgrounds.  As a result, the exploration of new experimental paradigms is required.  Recently, our community has seen specific use of low-temperature quantum sensors for BSM physics searches in rare nuclear decay (such as magnetic microcalorimeters (MMCs) and transition edge sensors (TES’)) which are characterized by their exceptionally high energy resolution (~eV) but suffer from a slow detector response thus limiting their applications in nuclear decay spectroscopy.  High-resolution cryogenic-charge sensitive quantum sensors like superconducting tunnel junctions (STJs) overcome this limitation and can count at rates 2-3 orders of magnitude higher than MMCs and TES’ making them exceptionally well suited for low-energy nuclear decay measurements.  In this talk, I will present the concept of SALER (the Superconducting Array for Low-Energy Radiation) to perform on-line decay measurements with STJ quantum sensors at RIB facilities.