MEASURE OF LOW RADIOACTIVE CONTAMINATION AND NUCLEAR RECOIL QUENCHINGFACTOR USING CRYOGENIC PARTICLE DETECTORS

For double beta decay and dark matter experiments the determination of the radioactive contamination of materials used is of fundamental imp ortance. The cryogenic particle detectors allow the realization of det ectors with various types of materials and in this way the radioactivi ty is measured in a calorimetric approach with very high sensitivity. In particular a new complete analysis for different types of leads, mo dern and ancient roman, was realized and here presented. The detector sensitivity for a nuclear recoil event is a crucial point in the dark matter experiments. The nuclear recoil detection efficiency for cryoge nic particle detectors was directly measured using two TeO2 crystals f acing one with other and performing a coincidence-anticoincidence anal ysis of the collected data. The determination of the quenching factor for low energy nuclear recoils in the TeO2 cryogenic detectors shows t hat these devices are very sensitive to a possible dark matter particl e interaction. In cryogenic detectors a nuclear recoil generates signa ls with the same amplitude of an electron with the same energy. The pe rformed measure and the data analysis will be discussed in detail. Fin ally the experimental setup and the preliminary test of the new array of TeO2 cryogenic detectors for double beta decay and dark matter sear ch will be discussed in detail.