High-resolution bolometers for rare events detection

Since many years the Milano Gran Sasso collaboration is developing large ma ss calorimeters for Double Beta Decay and Dark Matter searches, employing T eO2 crystals as absorber elements. Recently, we have focused our attention on the improvement of the detector resolution: an efficient dumping suspens ion and the implementation of a new cold electronics device, have strongly suppressed the main sources of noise. The increase in SIN ratio has been of almost an order of magnitude and the resolution achieved is competitive wi th that of Ge diodes for gamma -rays detection, while a FWHM of 3.2 +/-0.3 keV has been obtained for 5.4 MeV alpha particles, the best result with any kind of detector. (C) 2001 Elsevier Science B.V. All rights reserved.