A second generation experiment for direct neutrino mass measurement via 187Re β-decay

The calorimetric determination of the neutrino mass by means of cryogenic detector could play a significant role, being in principle able to investigate all the 10(-1) eV/c(2) region. However, the question is still open whether the development in this new technique will allow to confirm the expected performancies. A step forward in the advancement of this technology is represented by the incoming second generation experiment on the beta decay of Re-187 with superconducting Rhenium microcalorimeters. After the first pioneering experiment done in 1999 [2,3,6,7], we have undertaken an R&D phase for developing detectors with an energy resolution of about 5 eV, about 20 times better than that attained in the previous experiment. Here we describe the main features of the new experiment that is under construction, in which about 300 detectors will be under measurement for 1 year in order to reach an expected sensitivity of the eV/c(2).