Fundamental Research Division
The DRF at the CEA assemble approximately 6,000 scientists since January 2016.
Scientific result | Content of the Universe
In Gran Sasso, Italy, under 1400 meters of rocks, the international detector CUORE detectors (Cryogenic Underground Observatory for rare Events) has begun its long watch. One thousand bolometers containing 741 kg of tellurium dioxide (TeO2) cooled to 10 millikelvins are waiting to record the very rare radioactive decay of tellurium 130—this time not just a double-beta decay (emission of two electrons and two anti-neutrinos) but the even rarer, neutrinoless double-beta decay.
To increase the probability of detecting this event, the researchers at LUMINEU propose using "scintillating" bolometers, capable of measuring not only the very slight excess of heat that's a signature of radioactive decay, but also the light emission that it induces in the crystal. The latter acts as the emitter and detector at the same time. This innovative concept drastically reduces the surrounding radioactive background while preserving the exceptional energy resolution and efficiency of bolometers. Another essential point is picking the best nucleus among ten candidates: 100Mo.
Two crystals of approximately 200 g of Li2100MoO4 were produced and tested, one at the Modane Underground Laboratory (LSM), and the other at the Gran Sasso underground laboratory. According to this study, 200 kg of enriched crystals and a ten-year exposure should lead to a tenfold sensitivity increase on the absolute mass of the neutrino, compared to current experiments.
Beginning in November 2017, scintillating bolometers at LSM combined with twenty 210 g crystals will accumulate data for over a year. This demonstrator will provide the best global result on the double-beta decay of 100Mo, leading to the final choice of the crystal to be used in detector CUPID (Cuore Upgrade with Particle Identification), CUORE's successor.
First test of an enriched 116CdWO4 scintillating bolometer for neutrinoless double-beta-decay searches, The European Physical Journal C.Enriched TeO2 bolometers with active particle discrimination: towards the CUPID experiment, Physics Letters B.
Development and underground test of radiopure ZnMoO4 scintillating bolometers for the LUMINEU 0ν2β project, Journal of Instrumentation.
CEA is a French government-funded technological research organisation in four main areas: low-carbon energies, defense and security, information technologies and health technologies. A prominent player in the European Research Area, it is involved in setting up collaborative projects with many partners around the world.