Status of the HOLMES detector development

Nucciotti, A.; Alpert, B.; Becker, D.; Bennett, D.; Biasotti, M.; Brofferio, C.; Ceriale, V.; Ceruti, G.; Corsini, D.; Day, P.; De Gerone, M.; Dressler, R.; Faverzani, M.; Ferri, E.; Fowler, J.; Fumagalli, E.; Gard, J.; Gatti, F.; Giachero, A.; Hays-Wehle, J.; Heinitz, S.; Hilton, G.; Koester, U.; Lusignoli, M.; Maino, M.; Mates, J.; Nisi, S.; Nizzolo, R.; Orlando, A.; Parodi, L.; Pessina, G.; Pizzigoni, G.; Puiu, A.; Ragazzi, S.; Reintsema, C.; Ribeiro-Gomes, M.; Schmidt, D.; Schumann, D.; Siccardi, F.; Sisti, M.; Swetz, D.; Terranova, F.; Ullom, J.; Vale, L.

doi:10.1016/j.nima.2015.09.066

HOLMES is a new experiment to directly measure the neutrino mass with a sensitivity as low as 0.4 eV. HOLMES will perform a calorimetric measurement of the energy released in the electron capture decay of163Ho. HOLMES will deploy a large array of low temperature microcalorimeters with implanted163Ho nuclei. HOLMES baseline detector is an array of 1000 microcalorimeters each with an implanted163Ho activity of about 300 Bq, an energy resolution FWHM of about 1 eV at the spectrum end-point (Qâ2.5 keV), and a time resolution of about 1 Î¼s. Matching these performances requires a careful optimization of all components, from the microcalorimeters to the signal processing algorithms. We outline here the project technical challenges and the present status of the development.