Detecting scintillation light of NaI(Tl) crystals with SiPMsat cryogenic temperature

The direct search for dark matter interaction is a main open issue in astroparticle physics, and a promising technique is based on scintillation light detection with NaI(Tl) crystals to validate of refute the DAMA/LIBRA claim. The signal is observed in the (1 to 6) keV energy interval, where the main source of background is due to noise from the Photomultiplier Tubes used by all current generation experiments. This paper presents the ASTAROTH Project, whose goal is to achieve a significantly higher signal-to-noise ratio at the energies of interest and a lower threshold, by reading out the light from of NaI(Tl) crystals using arrays of cryogenic SiPMs. We present the characterisation of a first SiPM array with laser light in liquid nitrogen and the results of a cool-down of ASTAROTH’s custom cryostat where a NaI(Tl) crystal is coupled to the array.