DUSEL and the DarkSide of Physics

Dr. Kara Keeter
Idaho State University
Department of Physics

A world-class Deep Underground Science and Engineering Laboratory (DUSEL) is being built in the former Homestake mine in South Dakota, at the site of the Ray Davis solar neutrino experiment.  The unprecedented opportunities afforded by DUSEL will allow for a number of state-of-the-art next-generation experiments in nuclear and particle astrophysics.  One of the primary goals for building DUSEL is to provide dedicated infrastructure for dark matter detectors. 
The DarkSide detector (and its next generation version, MAX) will require large amounts of noble gases with ultra-low levels of elemental impurities such as H2O, O2, and N2.  We are designing a custom trace-gas analyzer based on Cavity Ring-Down Spectroscopy that is sensitive enough to the levels that are needed (< 1 ppb).  CRDS involves measuring the decay rate of the intensity of monochromatic light transmitted at mirrors enclosing a cavity filled with a sample of gas.  By comparing the decay rates for light at a resonance frequency of the contaminant of interest with that of light that is off-resonance, a direct measurement of the amount of absorbing material (the contaminant) is obtained.
I will give a brief introduction to dark matter and noble liquid-based dark matter detection, and describe the DarkSide and MAX detectors and the development of the custom CRDS analyzer.  An overview of DUSEL and DUSEL-related projects will also be given.