The CRAB project: Precise detection and simulation of nuclear recoils for the calibration of cryogenic detectors in the 100 eV energy range
Cryogenic detectors have reached energy thresholds of a few tens of electronvolts, for detector masses on the order of a gram. These characteristics make them valuable technologies for detecting low-energy nuclear recoils induced by coherent elastic scattering of reactor neutrinos or for the direct detection of light dark matter. A detailed understanding of the detector response to sub-keV nuclear recoils will however be crucial for interpreting future experimental data. The CRAB (Calibrated Recoils for Accurate Bolometry) project proposes using radiative thermal neutron capture to induce mono-energetic nuclear recoils in the 100 eV to 1 keV range, which can be leveraged for calibration purposes.
This work presents the experimental validation of the CRAB method through a first experiment with a portable thermal neutron source and a CaWO4 cryogenic detector. Following this first success, a high-precision experimental campaign is currently being prepared at a thermal neutron beamline of the Atominstitut in Vienna, with the goal of unlocking the full scientific potential of the method. In particular, details of the atomic collision cascade induced in the surrounding matter by recoiling atoms should be accounted for when predicting the CRAB expected energy spectra. Their modelisation using state-of-the-art solid-state simulation tools has been at the heart of this doctoral work.
Projet CRAB https://irfu.cea.fr/Phocea/Vie_des_labos/Ast/ast.php?t=fait_marquant&id_ast=5371
LEARN – Laboratoire d’études et d’applications des réactions nucléaires- Study and Applications of Nuclear Reactions
DPhN, LEARN