Speaker
Description
Charge-Coupled Devices (CCDs), particularly in their Skipper-CCD configuration, are silicon-based detectors capable of single-electron sensitivity and eV-scale energy thresholds. These properties make them promising candidates for direct detection of certain low mass dark matter candidates and coherent elastic neutrino-nucleus scattering (CE$\nu$NS). A critical requirement for such applications is a precise understanding of the ionization response of silicon nuclei recoiling from interactions with neutral particles. In this talk, we present measurements of nuclear recoil ionization efficiency down to $\sim10$ eV of ionization energy. Low-energy neutrons ($< 23$ keV), generated via a $^{124}$Sb$^9$Be photoneutron source, were used to induce nuclear recoils in silicon, and the resulting ionization signals were recorded using a Skipper-CCD. Further, results of an identification efficiency measurement for nuclear recoil energies down to 1.5 keV performed by irradiating a CCD with neutrons from an $^{241}$Am$^9$Be source will be discussed, demonstrating the capability of CCDs in distinguishing nuclear recoil signals from those that are not.
