Conceptual Design for SuperCDMS SNOLAB

Beyond the present dark matter direct detection experiment at the Soudan underground laboratory, the SuperCDMS Collaboration is engaged in R&D activities for a 100-kg scale germanium dark matter experiment nominally sited at SNOLAB (2070 m overburden of rock). The expected sensitivity after 3 years of running is 3x10(-46) cm(2) for the spin-independent cross section, an order of magnitude improvement over present exclusion limits for WIMP masses similar to 80 GeV/c(2). At this depth, and appropriate design of shielding and cryostat, neutron backgrounds will be negligible. The baseline design is an expanded version of CDMS II with Ge substrates (100x33 mm discs) instrumented with the iZIP phonon sensor layout to achieve the electron surface-event rejection power required.