Using scientific-grade CCDs for the direct detection of dark matter with the DAMIC-M experiment

Abstract

The DAMIC-M (Dark matter in CCDs at Modane) experiment, successor of DAMIC at SNOLAB (Sudbury Neutrino Observatory laboratory), is devoted to the search for dark matter (DM) candidates interacting with the electrons or the nuclei of the bulk silicon of fully depleted Charge-Coupled Devices (CCDs). A kilogram-sized target mass will be installed at the Modane underground laboratory which offers an excellent low background environment for rare-event searches. The implementation of the Skipper readout allows for multiple non-destructive pixel charge measurements, reaching a readout noise of a fraction of an electron. This perfect performance in terms of charge resolution can be limited by the radioactive background and the noise introduced by the external electronics. Much effort is put into the protection of the silicon from contamination by cosmic ray spallation, careful choice of the materials to support and shield the CCDs, and development of a new acquisition system with fast and sensitive electronics for the control and readout of a CCD. All these advancements will push the detection threshold down to a few eVs, improving the sensitivity of DAMIC-M by at least one order of magnitude with respect to previous experiments. I will present the current status of DAMIC-M describing our technological challenges and the solutions we have adopted, and introduce the ongoing assembly of a prototype detector, the Low Background Chamber, aiming at validating our final design options and produce the first scientific results.