Improved Modelling of Detector Response Effects in Phonon-based Crystal Detectors used for Dark Matter Searches

• Main Authors: Wilson, M. J, Zaytsev, A, von Krosigk, B, Alkhatib, I, Buchanan, M, Chen, R, Diamond, M. D, Figueroa-Feliciano, E, Harms, S. A. S, Hong, Z, Kennard, K. T, Kurinsky, N. A, Mahapatra, R, Mirabolfathi, N, Novati, V, Platt, M, Ren, R, Sattari, A, Schmidt, B, Wang, Y, Zatschler, S, Zhang, E, Zuniga, A
• Format: Journal Article
• Language: English
• Published: 24-06-2024
• Subjects: Physics - High Energy Physics - Experiment; Physics - Instrumentation and Detectors
• DOI: 10.48550/arxiv.2403.01259

Phys. Rev. D 109, 112018 (2024) Various dark matter search experiments employ phonon-based crystal detectors
operated at cryogenic temperatures. Some of these detectors, including certain
silicon detectors used by the SuperCDMS Collaboration, are able to achieve
single-charge sensitivity when a voltage bias is applied across the detector.
The total amount of phonon energy measured by such a detector is proportional
to the number of electron-hole pairs created by the interaction. However,
crystal impurities and surface effects can cause propagating charges to either
become trapped inside the crystal or create additional unpaired charges,
producing non-quantized measured energy as a result. A new analytical model for
describing these detector response effects in phonon-based crystal detectors is
presented. This model improves upon previous versions by demonstrating how the
detector response, and thus the measured energy spectrum, is expected to differ
depending on the source of events. We use this model to extract detector
response parameters for SuperCDMS HVeV detectors, and illustrate how this
robust modelling can help statistically discriminate between sources of events
in order to improve the sensitivity of dark matter search experiments.