DEAP-3600 dark matter experiment

Abstract

DEAP-3600 is a single phase liquid argon (LAr) dark matter experiment, located 2 km underground at SNOLAB, in Sudbury, Canada. The detector has 1 tonne fiducial mass of LAr. The target sensitivity to spin-independent scattering of 100 GeV weakly interacting massive particles (WIMPs) is 10$^{-46}$ cm$^{2}$. The DEAP-3600 background target is $<$ 0.6 background events in the WIMP region of interest in 3 tonne-years. The strategies to achieve this background include pulse shape discrimination to mitigate electron recoil and using ultra low radioactive materials for detector construction. Furthermore, to reduce neutron and alpha backgrounds, the DEAP-3600 acrylic vessel was sanded in situ to mitigate radon exposure of surfaces during construction and fabrication. The experiment is currently in the commissioning phase and will begin physics data taking later this year. This paper presents an overview of the experiment, its cross-section sensitivity to WIMPs and its current status.