Development of a Technical Design for the Germanium Observatory for Dark Matter at DUSEL

This proposal, from the California Institute of Technology, requests funds to develop a Preliminary Design for the Germanium Observatory for Dark Matter (GEODM), a 1.5 ton active mass WIMP search experiment with a WIMP nucleon elastic scattering cross section reach of 2 × 10 to the power of minus 47 cm**2 at 60 GeV WIMP mass using the technology of the CDMS II and SuperCDMS experiments. The detectors will be operated at the DUSEL 7400 foot level within a cryogenic, shielded apparatus designed to provide a zero-background raw exposure of 4.5 ton year over 4 years.

The award, through a Cooperative Agreement, will fund the California Institute of Technology and collaborators to produce a Preliminary Design for such an experiment to be constructed and run at the DUSEL underground laboratory. The case is made that (1) recent technical innovations improvements are a moderate risk evolution from current performance and thus are largely an engineering effort appropriate to the DUSEL S4 solicitation; (2) prior efforts on CDMS and SuperCDMS provide empirically verified technical performance and cost baselines, placing these estimates on a solid foundation; and (3) the team undertaking this effort has a proven strong track record of such evolutionary gains in background reduction, background rejection, increased target mass, and scientific reach. Because of these characteristics, GEODM provides an extremely promising path to significant gains in WIMP sensitivity or to detailed study of a possible WIMP signal at DUSEL. Further, the CDMS collaboration has contributed many novel technologies now in use by other groups and in other fields. GEODM will address the cost challenges of cryogenic detectors, which will likely broaden even further their use (e.g., for homeland security). Dark matter research provides students and postdocs with a diverse education and range of career avenues, as evidenced by the recent granting of six PhDs based on CDMS II work and the impressive number of former students and postdocs now in faculty and senior level laboratory positions.

The future of germanium technology in dark matter searches, and in the search for neutrinoless double-beta decay, rests on the development of time and resource-saving techniques for detector production.