Abstract:

The search for Weakly Interactive Massive Particles (WIMPs) which may constitute the Dark Matter in the Universe is clearly a high priority and is one of the justifications for the Deep Underground Science and Engineering Laboratory (DUSEL) in the US. The simultaneous athermal phonon and ionization measurement in germanium detectors at low temperature is are the only demonstrated technology which has negligible background in the search for WIMPs. The challenge is to extrapolate this approach to the ton scale within the next ten years with zero background and at reasonable cost and construction time. I will describe the approach we propose in our recent S4 proposal to NSF and an accompanying proposal to DOE and how this articulates with the pre-DUSEL program. I will emphasize the role that LBNL could play.