Calorimetric measurement of the 163Ho spectrum by means of a cryogenic detector

A cryogenic micro-calorimeter to investigate the electron capture decay of 163Ho has been developed. The interest for the 163Ho decay is related to its possible application in experiments to determine a limit on the electron neutrino mass. The preliminary results obtained with a prototype detector have demonstrated that a cryogenic micro-calorimeter permits to resolve the doublet NI NII, and the doublet MI MII of the 163Ho electron capture spectrum that gas proportional counters and semiconductor diode detectors were unable to separate. Assuming a zero neutrino mass, it has been calculated the end point QEC value.