Neutrino oscillation experiments have proved that neutrinos are massive particles but the assessment of their absolute\ud mass scale is still an outstanding challenge in today particle physics and cosmology. The laboratory experiments dedicated\ud to effective electron-neutrino mass determination are the ones based on the study of single beta decay or electron\ud capture (EC) decay. Exploiting only on energy-momentum conservation, this kinematic measurement is the only one\ud which permits to estimate neutrino masses without theoretical assumptions on neutrino nature and it is truly modelindependent.\ud To date the most competitive isotopes for a calorimetric measurement of the neutrino mass are 187Re and 163Ho. While the first decays beta, the latter decays via electron capture, and both have a Q-value around 2.5 keV.\ud The measurement of 163Ho EC is an appealing alternative to the 187Re beta decay measurement because few nuclei are\ud needed and it is a self-calibrating measurement. In this context the MARE project, based on rhenium thermal detectors\ud has been born.\ud We report here the status of MARE in Milan with Rhenium and the activity concerning the production of radioactive\ud 163Ho isotope in the framework of MARE

No abstract

The TES cryogenic detectors, due to their high spectral resolution and imaging capability in the soft X-ray domain, are the reference devices for the next proposed space missions whose aims are to characterize the spectra of faint or diffuse sources. ATHENA is the re-scoped IXO mission, and one of its focal plane instrument is the X-ray Microcalorimeter Spectrometer (XMS) working in the energy range 0.3-10 keV. XMS will be able to achieve the proposed scientific goals if a background lower than 0.02 cts/cm 2 /s/keV is guaranteed. The studies performed by GEANT4 simulations depict a scenario where it is mandatory to use an active Anti-Coincidence (AC) to reduce the expected background in the L2 orbit down to the required level. This is possible using a cryogenic AC detector able to provide a rejection efficiency of about 99%. We are developing for this purpose a TES-based detector made by Silicon absorbers (total assembled area about 1 cm 2 and 300 µm thick) and sensed by a Ir:Au TES. All the work done for IXO is applicable to ATHENA, with more margins due to the smaller area required for the detector. Here we present the results obtained from different samples, as a step towards the final detector design.

No abstract

No abstract