SENSEI: Characterization of Single-Electron Events Using a Skipper-CCD

Abstract

We use a science-grade Skipper Charge Coupled Device (Skipper-CCD) operating in a low-radiation background environment to develop a semi-empirical model that characterizes the origin of single-electron events in CCDs. We identify, separate, and quantify three independent contributions to the single-electron events, which were previously bundled together and classified as "dark counts": dark current, amplifier light, and spurious charge. We measure a dark current, which depends on exposure, of (5.89+-0.77)x10^-4 e-/pix/day, and an unprecedentedly low spurious charge contribution of (1.52+-0.07)x10^-4 e-/pix, which is exposure-independent. In addition, we provide a technique to study events produced by light emitted from the amplifier, which allows the detector's operation to be optimized to minimize this effect to a level below the dark-current contribution. Our accurate characterization of the single-electron events allows one to greatly extend the sensitivity of experiments searching for dark matter or coherent neutrino scattering. Moreover, an accurate understanding of the origin of single-electron events is critical to further progress in ongoing R&D efforts of Skipper and conventional CCDs.

9 pages, 6 figures, 4 tables

References in corpus (3)

• Single-electron and single-photon sensitivity with a silicon Skipper CCD
• SENSEI: Direct-Detection Constraints on Sub-GeV Dark Matter from a Shallow Underground Run Using a Prototype Skipper-CCD
• DAMIC-M Experiment: Thick, Silicon CCDs to search for Light Dark Matter

Cited by in corpus (22)

• EXCESS workshop: Descriptions of rising low-energy spectra
• SENSEI: First Direct-Detection Results on sub-GeV Dark Matter from SENSEI at SNOLAB
• Searches for light dark matter using condensed matter systems
• Search for coherent elastic neutrino-nucleus scattering at a nuclear reactor with CONNIE 2019 data
• Skipper-CCD Sensors for the Oscura Experiment: Requirements and Preliminary Tests
• SENSEI at SNOLAB: Single-Electron Event Rate and Implications for Dark Matter
• Absorption of Axion Dark Matter in a Magnetized Medium
• Confirmation of the spectral excess in DAMIC at SNOLAB with skipper CCDs
• Fast Single-Quantum Measurement with a Multi-Amplifier Sensing Charge-Coupled Device
• Low-Energy Backgrounds in Solid-State Phonon and Charge Detectors
• Skipper-in-CMOS: Non-Destructive Readout with Sub-Electron Noise Performance for Pixel Detectors
• Multi-Amplifier Sensing Charge-coupled Devices for Next Generation Spectroscopy
• Searches for CEνNS and Physics beyond the Standard Model using Skipper-CCDs at CONNIE
• Cherenkov Photon Background for Low-Noise Silicon Detectors in Space
• Readout Optimization of Multi-Amplifier Sensing Charge-Coupled Devices for Single-Quantum Measurement
• SENSEI: A Search for Diurnal Modulation in sub-GeV Dark Matter Scattering
• Extracting Halo Independent Information from Dark Matter Electron Scattering Data
• Dual-sided Charge-Coupled Devices
• Light-tight skipper-CCDs for X-ray detection in space
• Revisiting the Dark Matter Interpretation of Excess Rates in Semiconductors
• Characterization of the Cherenkov Photon Background for Low-Noise Silicon Detectors in Space
• Skipper-CCDs: current applications and future