2–6 Dec 2024
CERN
Europe/Zurich timezone

Development of Position Sensitive Deep Transient Spectroscopy as a background mitigation tool for CCD-based dark matter searches

4 Dec 2024, 10:20
20m
500/1-001 - Main Auditorium (CERN)

500/1-001 - Main Auditorium

CERN

400
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WG3 Radiation Damage - Extreme Fluence WG3 - Radiation Damage

Speaker

Dr Vagelis Gkougkousis (University of Zurich)

Description

The unparalleled sensitivity achieved with skipper CCDs, coupled with ultra-pure high-resistivity substrates (>22 kOhm×cm) and cryogenic operation, has rekindled interest in this technology for low-background experiments (DAMIC@SNOLAB, DAMIC-M, SENSEI, and OSCURA) Such devices offer sub-electron noise resolution, enabling the detection of extremely low-energy interactions critical for rare-event searches, including dark matter detection and neutrino studies. However, exposure to alpha particles and cosmic rays may induce lattice defects with extended annealing times, potentially degrading resolution and increasing background noise. We propose a novel method to mitigate these effects by integrating Laplace Deep-Level Transient Spectroscopy (DLTS) with electrical state pumping through the bias line, combined with the sequential readout of CCDs. Utilizing a lock-in amplifier synchronized to the shift register clock, we achieve pixel-by-pixel readout following charge injection. This approach addresses the inherent loss of timing information in charge-accumulating devices through a frequency scan at the pumping signal level. The method can be applied across various temperature points and injection levels, with an operational range typically spanning 120 K to 200 K. By conducting measurements at multiple injection and thermal conditions, we aim to characterize and mitigate background effects caused by lattice defects.

Type of presentation (in-person/online) in-person presentation
Type of presentation (I. scientific results or II. project proposal) I. Presentation on scientific results

Author

Dr Vagelis Gkougkousis (University of Zurich)

Presentation materials