CALDER (Cryogenic wide-Area Light Detectors with Excellent Resolution) wants to contribute in settling two important issues that particle physics is now facing: 1) Is the neutrino a standard particle or is it equal to its own antiparticle, as predicted by Ettore Majorana? The answer is of fundamental importance in the global framework of particle interactions and in cosmology, and could come from the observation of a rare nuclear process called "neutrinoless double beta decay". 2) What is the the “dark” matter filling the Universe made of? We know that it is different from the ordinary matter, however we still do not know what it actually is.

The goal of CALDER is to develop high-sensitivity cryogenic light detectors for the identification of rare events, such as double beta decay and dark matter interactions with ordinary matter. We are developing a new technology based on superconducting resonators. We are currently designing the prototypes in the Sapienza laboratory, in collaboration with the Italian Institute for Photonics and Nanotechnologies. Then the detectors will be installed in the CUORE and LUCIFER experiments running at the Gran Sasso underground laboratories of INFN to enhance their performances.

Video in Italian of my presentation at Piano Triennale INFN 2014 - Trento.


CUORE (Cryogenic Underground Observatory for Rare Events) is one of several next generation 0νββ experiments. CUORE will study the possible 0νββ decay of 130Te with a sensitivity to a half life of 2.1×1026 yr (68% C.L.), which corresponds to an effective neutrino mass of less than 24 − 81 meV. The primary physics goal of CUORE is to determine whether 0νββ occurs and, if so, to determine the half-life of the process, the Majorana/Dirac nature of the neutrino, the neutrino mass scale, and mass hierarchy.

Infrastructure for CUORE is currently under construction in Hall A at LNGS and components for CUORE are being manufactured around the world. The CUORE detector will be a tightly packed array of 988 TeO2 bolometer modules, each 5×5×5 cm3 and 750 g, for a total mass of 741 kg of TeO2. Since the tellurium is unenriched, 204 kg of the total mass is the isotope of interest, 130Te. The bolometer modules will be arranged in 19 towers of 13 floors each, with 4 crystals per floor (see the figure above). The CUORE detector will be housed in a specially built cryostat and cooled to about 10 mK by a pulse-tube-assisted dilution refrigerator.

Articolo su DA N. 1 2014 (pagina 41)


The goal of LUCIFER is to build a background-free 0νββ experiment with a discovery potential better than the future, already approved, funded experiments. Although aiming at a discover, in the case of insufficient sensitivity the LUCIFER technique will be the demonstrator for a higher mass experiment able to probe the entire inverted hierarchy region of the neutrino mass and to start approaching the direct one. The idea of LUCIFER is to join the bolometric technique proposed for the CUORE experiment (one of the few 0νββ experiments in construction world-wide) with the bolometric light detection technique used in cryogenic dark matter experiments. The bolometric technique allows an extremely good energy resolution while its combination with the scintillation detection offers an ultimate tool for background rejection. Preliminary tests on several 0νββ detectors have clearly demonstrated the excellent background rejection capabilities that arise from the simultaneous, independent, double readout (heat + scintillation).