Compton step calibration feasibility study for SuperCDMS SNOLAB detectors

SuperCDMS SNOLAB will be a direct detection experiment with world-leading sensitivity for low-mass dark matter (DM) that employs cryogenic silicon and germanium calorimeters. The experimental infrastructure is expected to be commissioned in early 2024. Because of an expected non-linear energy response of SNOLAB detectors, a precise calibration over the entire energy range of DM models under investigation will be required. Insertable radioactive sources with known gamma lines and germanium activation lines constitute the primary calibration method for SuperCDMS detectors. One of the complementary methods proposed for silicon-based detectors is to make use of Compton steps providing two energy signatures at ∼0.1 keV and ∼2 keV which covers the energy range for sub-GeV DM searches. Compton step calibration is actively explored at test facilities running SuperCDMS silicon high-voltage, eV-scale (HVeV) prototype detectors. In this talk, we will present the status of the Compton step calibration performed on the HVeV detectors.