@article{10902/35560,
year = {2024},
month = {8},
url = {https://hdl.handle.net/10902/35560},
abstract = {Charge-coupled devices (CCDs) are a leading technology in direct searches for dark matter because of their eV-scale energy threshold and micrometer-scale spatial resolution. Recent studies have also highlighted the potential for using CCDs to detect coherent elastic neutrino-nucleus scattering. The sensitivity of future CCD experiments could be enhanced by distinguishing nuclear recoil signals from electronic recoil backgrounds in the CCD silicon target. We present a technique for event-by-event identification of nuclear recoils based on the spatial correlation between the primary ionization event and the defect cluster left behind by the recoiling atom, later identified as a localized excess of leakage current under thermal stimulation. By irradiating a CCD with an ²⁴¹ Am⁹Be neutron source, we demonstrate  >93% identification efficiency for nuclear recoils with energies  >150  keV, where the coincident ionization events were confirmed to be nuclear recoils due to their topology. The technique remains fully efficient down to 90 keV, decreasing to 50% at 8 keV and reaching (6±2)% between 1.5 and 3.5 keV. Irradiation with a ²⁴Na gamma-ray source does not result in any detectable defect clusters, with the fraction of electronic recoils with energies  <85  keV that are spatially correlated with defects  <0.1%.},
organization = {We acknowledge financial support from the following agencies and organizations: the U.S. Department of Energy Office of Science through the Dark Matter New Initiatives program; the U.S. National Science Foundation through Grant No. NSF PHY-2110585 to the University of Washington and The University of Chicago; Swiss National Science Foundation through Grant No. 200021_153654 and via the Swiss Canton of Zurich; IFCA through Project No. PID2019–109829GB-I00 funded by MCIN/AEI. We thank the College of Arts and Sciences at the University of Washington for contributing the first CCDs to the DAMIC-M project. The CCD development at Lawrence Berkeley National Laboratory MicroSystems Lab was supported in part by the Director, Office of Science, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.},
publisher = {American Physical Society},
publisher = {Physical Review D, 2024, 110(4), 043008},
title = {Nuclear recoil identification in a scientific charge-coupled device},
author = {McGuire, K.J. and Chavarria, A.E. and Castello-Mor, N. and Lee, S. and Kilminster, B. and Vilar Cortabitarte, Rocío and Alvarez, A. and Jung, J. and Cuevas-Zepeda, J. and Dominicis, C. De and Gaïor, R. and Iddir, L. and Letessier-Selvon, A. and Lin, H. and Munagavalasa, S. and Norcini, D.},
}