DELight: A Direct search Experiment for Light dark matter with superfluid helium

Abstract

To reach ultra-low detection thresholds necessary to probe unprecedentedly low Dark Matter masses, target material alternatives and novel detector designs are essential. One such target material is superfluid ^44He which has the potential to probe so far uncharted light Dark Matter parameter space at sub-GeV masses. The new “Direct search Experiment for Light dark matter”, DELight, will be using superfluid helium as active target, instrumented with magnetic micro-calorimeters. It is being designed to reach sensitivity to masses well below 100 MeV in Dark Matter-nucleus scattering interactions.