Construction and performance of fast thermal detectors of alpha particles and X-rays

Three new silicon bolometers have been constructed and exposed to alpha particles and X-rays at temperatures down to 10 mK in a dilution refrigerator. The low impedence of these detectors enabled us to achieve, together with energy resolutions comparable with those of similar counters, much faster pulse risetime. The flexibility of these bolometers allows measuring energies from a few keV to tens of MeV.