STUDY OF IONIZATION PARTICLE DETECTORS AT MILLIKELVIN TEMPERATURES

We present the results of germanium and silicon ionization detectors t ests at 20-100 mK. Such devices allow for particle identification when used in coincidence with bolometric detection in particular for dark matter search. We obtained 1.7 keV (FWHM) resolutions for 10-100 keV X -rays on 4-10 mm thick germanium and 3 mm thick silicon pin diodes. We also studied the performances of a ''solid ionization chamber'' with evaporated aluminium electrodes. We focused our attention on the carri ers trapping which alter the detector performances