Science Arguments for a National Underground Laboratory Wick Haxton, University of Washington

Over the past two years possibilities for creating a deep underground science laboratory in the US have been discussed. While the driver for this laboratory is physics -- a broad program of solar, supernova, and atmosphericneutrino measurements, proton decay, dark matter searches, long-baseline accelerator neutrino oscillation experiments, and double beta decay -- there is also significant interest from geomicro-biology, earth sciences, and various applied sciences. I review some of the science possibilities and discuss why a very deep laboratory is needed. One existing facility, the soon to be abandoned Homestake Mine in South Dakota, is of special interest. This operating facility extends to 8000 feet and has massive shafts and hoists, sophisticated ventilation and air conditioning systems, fiber optics, sensor, and communications systems, hydroelectric power generators, and a skilled staff of engineers, geologists, and miners who understand how to operate a complex facility. I describe plans for converting this site into a dedicated National Underground Science Laboratory.