Mi-Beta

Home page of the Experiment: http://crio.mib.infn.it/wig

This experiment is based on the use of micro-bolometers for high resolution energy independent X - ray spectroscopy and measurements of the decay of 187Re in view of the determination of the mass of the electron antineutrino. In thermal detectors micro-bolometers due to their low heat capacity can reach energy resolutions (see later) superior by more than an order of magnitude then any other detector. The measurement of the spectrum of 187Re is very promising because this b active nucleus has the lowest transition energy in Nature. The basic idea of these experiments, carried out surprisingly in the world only in the Sezioni of Genoa and Milan, is to perform a "calorimetric" experiment to determine, unlike in electron spectrometers, not only the electron energy, but the entire energy released in the detector. In this sense these experiments are to be considered as complementary to those carried out with electron spectrometers. In addition the lifetime of the 187Re decay (~43 Gyear) is of the same order of the life of the Universe and therefore very important in Cosmochronology.