Preliminary Results of the MARE Experiment.

The microcalorimeter array for a rhenium experiment (MARE) project aims at the direct and calorimetric measurement of the electron neutrino mass with sub-eV sensitivity. The design is based on large arrays of thermal detectors to study the beta decay of $$^{187}$$ Re and the electron capture of $$^{163}$$ Ho. One of the activities of the project, MARE 1 in Milan, has started in Milan using one array of 6 $$\times $$ 6 silicon implanted thermistors equipped with AgReO $$_4$$ absorbers. The purposes of MARE 1 in Milan are to achieve a sensitivity on the neutrino mass of a few eV and to investigate the systematics of $$^{187}$$ Re neutrino mass measurements, focusing on those caused by the beta environmental fine structure and the beta spectrum theoretical shape. In parallel, the MARE collaboration is performing an R&D work for producing absorbers embedded with radioactive metal $$^{163}$$ Ho. We report here the status of MARE using Re as beta source and the preliminary results obtained with $$^{163}$$ Ho. [ABSTRACT FROM AUTHOR]