Cryogenic detectors with single-electron sensitivity for Dark Matter searches – CRYOSEL

The objective of the CRYOSEL proposal is to develop and exploit a massive (30 g) cryogenic Ge detector sensitive to the single electron-hole pair, in order to search for the interaction of light Dark Matter particles with electrons (ER) or nuclei (NR). A resolution of 0.1 pair is obtained by the Luke-Neganov amplification of the thermal signal associated to the drift of the charges in the detector. The background of purely thermal signals (not associated with ionization) is rejected by requiring a coincidence with the detection of at least one electron in an array of superconducting lines covering a surface of the crystal. The detector will be used in the low-radioactivity environment of the LSM to search for ER-induced DM signals in the 0.1 to 100 MeV/c2 mass range and NR-induced signals for range from 0.1 to 1 GeV/c2. A laser-pulse injection system and an AmBe neutron source will be used for the calibration of the response to single-electron and nuclear recoil events, respectively.