An analysis of the sensitivity of a low pressure time projection chamber to a directional anisotropy due to WIMP interactions

Abstract

The Dark Matter Time Projection Chamber (DMTPC) collaboration is a dark matter direct detection effort which develops TPCs to observe and reconstruct nuclear recoils generated by incident particles. If some of these recoils are the result of dark matter interactions, we can in theory observe an anisotropy in the direction of these recoils which is consistent with the galactic halo models of dark matter. Such an observation would serve as convincing evidence that these incident particles have an extrasolar origin. In this thesis I discuss the workings of a TPC known as the 4-shooter, the analysis used to identify nuclear recoil candidates, and the mathematics to quantify the anisotropy of a distribution. I then discuss the ways in which the pressure of the target gas in the TPC affects rejection power, and construct a framework to determine an optimal operating pressure for the 4-shooter and future DMTPC detectors.