Bolometers as Particle Spectrometers

A spectrometer based on low-temperature calorimetry is under development since 1983. The present detector, capable of recording individual alpha and beta particles and X-ray photons, is based on a composite diamond-germanium bolometer. The advantage of a composite bolometer is that it separates the absorption and detection functions. Diamond, as an absorber, is of particular advantage because of its low heat capacity and high thermal diffusivity. The goal is a theoretical energy resolution of a few eV at 0.1/sup 0/K. Our initial experiments at 1.3/sup 0/K and 0.9/sup 0/K, which give resolutions in the keV range, are still noise limited. High-resolution applications, such as in X-ray astronomy and nuclear physics - in particular neutrino mass measurements - are forseen.