Identification of Dark Matter 2010-IDM2010

The Dark Matter Time Projection Chamber (DMTPC) experiment uses CF4 gas at low pressure (0.1 atm) to search for the directional signature of Galactic WIMP dark matter. We describe the DMTPC apparatus and summarize recent results from a 35.7 g-day exposure surface run at MIT. After nuclear recoil cuts are applied to the data, we find 105 candidate events in the energy range 80−200 keV, which is consistent with the expected cosmogenic neutron background. Using this data, we obtain a limit on the spin-dependent WIMP-proton cross-section of 2.0 × 10−33 cm2 at a WIMP mass of 115 GeV/c2. This detector is currently deployed underground at the Waste Isolation Pilot Plant in New Mexico