The DEAP-3600 Dark Matter Search Experiment - Updates and Commissioning results
Tina Pollmann (SNOLAB/Laurentian University)

The DEAP-3600 experiment uses a 3.6 tonne liquid argon target for a direct dark matter search with a projected sensitivity to the spin-independent WIMP-nucleon cross-section of 10^-46 cm^2 at 100 GeV WIMP mass after a three-year background-free exposure.

DEAP is operated as a single-phase detector. The liquid argon volume is viewed by 255 high efficiency photo multiplier tubes, which record the scintillation light emitted when particles interact there. The resulting pulse shapes allow very efficient rejection of the overwhelming electromagnetic backgrounds from the dark matter signal region using pulse shape discrimination.

To meet the detector’s extremely stringent background targets, remaining backgrounds are suppressed through several layers of active and passive shielding - including 6000 m.w.e of rock overburden, through material screening, through the use of clean construction techniques, through careful detector design, and in offline analysis through fiducialization.

The DEAP detector was built between the years of 2011 and 2016 at the SNOLAB facility, 2 km underground, and is currently taking commissioning data. We will present the status of the experiment and results from analysis of the first commissioning data on behalf of the DEAP-3600 collaboration.