Underground science research facilities in the United States, the transition from mine tenant to facility operator

Abstract

The underground physics research community (UPRC) in the United States has historically conducted research in underground mines. Because underground mines exist for the purposes of ore extraction, research activities sometimes take a secondary role. Underground science has matured, as second and third generation experiments have demonstrated the continuing benefit of such research. Success breeds interest, so the demand for underground research space has increased. Hence the need for a dedicated underground laboratory has been recognized and pursued. Underground physics research in the United States began with several cosmic ray studies in the 1950s. In the 1960s, future Nobel Prize winner Fred Reines and his associates observed cosmic-ray produced neutrinos at the famous East Rand Proprietary Gold Mine near Johannesburg, South Africa. The first large-scale US detector was located at the Homestake gold mine in Lead, South Dakota. The detector was a 380,000-liter tank of perchloroethylene, a cleaning fluid. Subsequent experiments included: the water Cerenkov detector for the Irvine-Michigan-Brookhaven (IMB) experiment, located 600 m underground in the Morton salt mine near Cleveland, OH; the Harvard-Purdue-Wisconsin (HPW) experiment 650 m underground in Park City, UT; and the Soudan 2 proton decay experiment located 713 m underground at the Soudan Underground Mine State Park in northeastern Minnesota. International underground physics laboratories include: Gran Sasso, Pyhasalmi mine, Kamioka Mozumi mine, Sudbury Neutrino Observatory at the INCO Creighton mine, and the Boulby mine. The underground physics research community in the US is pursuing a sole-purpose National Underground Science Laboratory. Candidate sites are: Homestake mine, Mount San Jacinto, Soudan mine, WIPP site and the Henderson mine. The next-generation nucleon decay experiment, tentatively called UNO, will require a cavern 60 m wide by 60 m high by 180 m long at a depth on the order of 1,500 m. The transition from a single experiment facility to a multiple experiment facility requires development of a separate operating authority. The authority must deal with the new institutional issues associated with balancing the laboratory versus experiment issues, including different sources of funding, shared responsibilities and liabilities, experiment rights and conflict resolution, decommissioning, and provided services. In all inhabitable building spaces, whether above- or underground, providing fire and life safety is the most important design requirement. For the underground science laboratories, this must be accomplished in the underground environment, and in the framework of several mining, occupational and building codes. The underground environment, while inhospitable in some ways, is a necessity for current and future high-energy physics research. Deep underground space can be developed to make regular human occupation safe, functional and appealing. The benefits are clear for a single-purpose underground facility, where underground science is the sole reason for being underground. Sites for an US National Underground Science Laboratory are many and varied. The challenge remains to develop and fund the best site. (A). Reprinted with permission from Elsevier. For the covering abstract see ITRD E124500.