Today at Berkeley Lab

How an Underground Science Facility Got Off the Ground

By Glenn Roberts


(l-r) Mike Headley, SURF lab director, executive director, South Dakota Science and Technology Board; Ron Wheeler, vice chairman, SDSTA Board; Sen. Mike Rounds, R-S.D.; Kevin Lesko; James Symons, Associate Laboratory Director, Berkeley Lab.

In the Black Hills of South Dakota, extending nearly a mile below ground, is one of the nation’s premier sites for experiments seeking out the nature of dark matter and ghostly particles known as neutrinos, among other experiments that make use of the depth and geology of the site.

Berkeley Lab has played a critical role in establishing, developing and operating Sanford Underground Research Facility (SURF), in Lead, S.D. The site has become an important fixture in the global science community and a welcome neighbor for its surrounding communities.

Starting in the late 1960s and extending for nearly three decades, the site was home to the famous Homestake Chlorine experiment (also known as the Davis experiment), with which Ray Davis first detected solar neutrinos and was awarded the Nobel Prize in 2002. This observation led to the so-called solar neutrino problem—an apparent discrepancy in the number of neutrinos expected to be produced in the sun’s interior that ultimately was resolved in the Nobel Prize-winning discovery of neutrino oscillations.

More recently, SURF hosted the world leading Large Underground Xenon experiment, or LUX. Berkeley Lab was DOE’s lead laboratory for LUX, which having completed its experimental run in searching for dark matter is now being dismantled to make way for a more sensitive experiment: LUX-ZEPLIN (LZ). LZ, led by Berkeley Lab, will be about 30 times more sensitive than LUX. Ironically, LZ may be limited by the interfering “noise” of astronomical neutrinos in its hunt for dark matter. LZ will occupy the same underground space that once housed the Homestake experiment.

Among other experiments and facilities in progress at the site with significant involvement by Berkeley Lab staff:

  • The Majorana Demonstrator, which is searching for evidence of a theorized phenomenon known as “neutrinoless double-beta decay” that could help explain whether neutrinos are their own antiparticle and why there is more matter than antimatter in the universe.
  • CASPAR, a nuclear astrophysics facility, is taking shape under the guidance of Notre Dame University and the South Dakota School of Mines and Technology.
  • The Black Hills State University Underground Campus (BHUC), a world-leading low-background assay facility led by Berkeley Lab and Black Hills State University (BHSU). Housing four low background high purity Germanium gamma-ray screeners, the BHUC campus is providing most of the assay services for LZ, the Majorana Demonstrator and a half-dozen other experiments. Berkeley Lab, BHSU and UC Berkeley will be installing a pair of new detectors later this fall while other collaborators will be commissioning another two to three detectors in the coming six months.

SURF will host the international Deep Underground Neutrino Experiment (DUNE) that will include huge underground particle detectors at SURF and a high-intensity neutrino beam at Fermi National Accelerator Laboratory (known collectively as the Long-Baseline Neutrino Facility or LBNF). LBNF/DUNE requires the excavation of three large caverns a mile underground at SURF and represents the most ambitious physics project since the construction of the Large Hadron Collider at CERN in Switzerland. The DUNE collaboration already includes more than 160 institutions from around the globe, and CERN is a leading partner to develop and deliver key components for the project.

Because of Fermilab’s major role in the Long Baseline Neutrino Facility that is taking shape at SURF, the management of SURF transferred from Berkeley Lab to Fermilab on Oct. 1.

Lesko, who served as the head of the SURF operations office, was instrumental in the effort to transform South Dakota’s former Homestake gold mine into a research facility in 2000. Lesko led the team that submitted a proposal for the use of the Homestake Site with UC Berkeley as the lead institution and was funded in 2005 to develop a conceptual design report.

Between 2005 and 2007 Lesko helped to form the Homestake Collaboration, forging strong ties to the South Dakota Office of the Governor and the South Dakota Science and Technology Authority (SDSTA). He also helped to establish advisory committees, and solicited letters of interest from scientific collaborations interested in being hosted at Homestake. The Conceptual Design Report was completed in January 2007 and was the first of four reports the team submitted to the National Science Foundation (NSF).

Working with the South Dakota Legislature, Gov. Mike Rounds secured $40million for the conversion of the former Homestake mine into a science facility. In June 2006, T. Denny Sanford donated $70 million for the creation of the facility.

Lesko recounted, “I have worked with three Governors of South Dakota, five executive directors of the SDSTA, and all of the South Dakota congressional delegation for the past decade. No individual has maintained a clearer picture of the impact of an underground research facility on his state nor strived harder to achieve a world-class facility than has Mike Rounds.”

In June 2007, the NSF’s site-selection process picked Homestake as the site for a deep underground laboratory, and for roughly three years thereafter continued to develop the designs for a deep underground laboratory while simultaneously developing the early science program funded with state of South Dakota funds and a philanthropic donation by T. Denny Sanford.

The DOE Office of Science funded operations of SURF when the NSF funds were exhausted while it considered options for its experiments.

In 2011, Berkeley Lab stepped up to manage and oversee the operations of SURF for the Department of Energy, establishing the SURF Operations office within the Berkeley Lab Physics Division. DOE support of Homestake enabled the LUX dark matter and the Majorana Demonstrator experiments to proceed.

Lesko noted, “A collection of biology and earth science experiments are making increasing use of the Sanford Facility’s underground infrastructure including a significant effort by kiSMET,” an effort to measure the effects of hydraulic fracturing.

Rounds, now a U.S. senator, said in a statement about SURF, “The research being conducted at the Sanford Underground Research Facility is vital to learning more about particle physics, neutrinos and what makes up our universe.

“Berkeley Lab has been a critical partner since the very beginning. I thank Dr. Lesko for his hard work and dedication to Homestake and SURF over the past 16 years and wish Kevin and his team the best of luck in their future endeavors.”

-Berkeley Lab’s Kevin Lesko contributed to this article.