Speaker
Description
In direct detection searches for scattering of electrons off low-mass (sub-GeV) DM, a promising approach to address problematic backgrounds and penetrate the "neutrino fog" is to exploit Earth’s daily rotation relative to the direction of the DM wind, which can result in a modulation of the expected signal rate. Organic scintillating crystals contain an intrinsic anisotropy in their crystalline structure which manifests as a directionally-sensitive scintillation threshold. Particularly for DM masses around 1 MeV, this is expected to result in an O(1) daily modulation in the signal rate in the case of optimal crystal alignment. Meanwhile, decoupling the scattering target from the readout sensor allows for more cost-effective scaling. We present here the proof-of-concept for a prototype directional DM detector using anisotropic scintillating crystals optically coupled to Skipper-CCD photosensors. In future, the prototype could be scaled up in an "ice cube tray"-like configuration, and installed in a cryostat at SNOLAB. Given that SNOLAB currently hosts the DAMIC infrastructure, this would be a natural continuation of the CCD program at the lab.