High Statistics Decay Recoil Experiments with Superconducting Tunnel Junctions

The BeEST experiment is a case example of the use of superconducting tunnel junction (STJ) sensors for precision nuclear physics to study neutrinos in the electron capture decay of ⁷Be. In Phase I of the experiment, world leading constraints were placed on the sterile neutrino mass. More recently, Phase III data was used to place experimental constraints on the neutrino spatial wavepacket with new constraints on the sterile neutrino mass expected soon. In this talk I will discuss the BeEST collaborations progress towards Phase IV (at PNNL) and future projects such as SALER (at FRIB) and proposed work ASGARD, that seek to expand the applications of STJ sensors to study short-lived isotopes.