Optimization of Cryogenic Ge Detector Equipped with NbSi Thin Film Thermometers: Fiducial Volume and Energy Resolution

Ionisation-heat detectors are very useful in direct detection dark matter experiments because they lead to an active rejection of the background. Their rejection performances are presently limited by near electrode surface events leading to incomplete charge collection. We propose an identification of near NbSi electrodes events based on pulse shape analysis of the phonon signal delivered by the thermometric layer. We discuss recent progress in the near surface event identification accuracy together with the remaining fiducial volume and the heat channel resolution.