Speaker
Description
CEνNS and dark matter experiments aim to detect interactions producing low-energy nuclear recoils using cryogenic detectors with excellent energy resolution (~5 eV) and low thresholds (~20 eV). However, these detectors currently lack a proper calibration method to probe new physics. The CRAB (Calibrated Recoils for Accurate Bolometry) experiment aims to calibrate cryogenic detectors with pure nuclear recoils in the sub-keV range, in the whole detector volume, and with sub-percent precision. These recoils are produced by thermal neutron radiative capture emitting a single gamma and subsequently a pure nuclear recoil with a known energy. A new experimental setup has been installed and commissioned at the TRIGA Mark-II research reactor at the AtomInstitut in Vienna in 2024. The cryostat is exposed to a collimated thermal neutron beam and coupled to gamma detectors, enabling the measurement of the nuclear recoil in coincidence with the gamma emitted following the neutron capture.
This poster will present sub-percent accuracy measurements of two nuclear recoil peaks at 575 eV and 1144 eV with an Al₂O₃ cryogenic detector having a 6 eV baseline energy resolution. To better understand the detector response and to be able to translate this nuclear calibration at other experimental sites, I will also discuss new ongoing developments to perform a direct inter-calibration with electronic recoils. This new setup will include LED bursts and low-energy X-rays. This inter-comparison will also shed new light on solid-state physics.