WE-P4-3 15:15

The DEAP 10 Kg Prototype, Kevin Graham , Queen's University — It is now observationally well-established that most of the matter in the universe is in the form of an, as yet unknown, ‘dark matter’. The currently favoured solution to the dark matter question postulates the existence of weakly interacting massive particles (WIMP). If these particles exist, it is expected that they will permeate space at the Earth and can be detected by terrestrial experiments. A variety of initial attempts to directly discover dark matter particles have been carried out and include such experiments as CDMS, PICASSO, and DAMA. No evidence for WIMPs has been found, but significant portions of the allowed parameter space remain unexplored. These experiments are designed to be sensitive to the nuclear recoil energy deposited by WIMPs scattering off of nuclei in the detector medium. Such events typically deposit 10's of keV of energy and must be distinguished from the large background of beta/gamma and alpha events.

The aim of the DEAP experiment is to utilize the characteristic differences in scintillation light between beta/gamma events and nuclear recoils in liquid argon to search for dark matter. A brief introduction to dark matter detection and the specific principles involved for DEAP will be presented. The current phase of the experiment, consisting of a 10 kg prototype, will be described and data from initial measurements presented.