From Sanford Underground Research Facility: “Science impact”

SURF logo
Sanford Underground levels

From Sanford Underground Research Facility

Erin Broberg
Matthew Kapust, photographer

Sanford Lab’s dedication to science, research and development and engineering, as well as its innovative approach to education, make it a world-leading science facility.

Dark matter science impacts

The LZ experiment is the upgraded successor to the highly successful Large Underground Xenon (LUX) experiment. LUX held world-leading sensitivity for approximately three and a half years over most of the WIMP-mass region. The LZ experiment was one of two direct-search, next-generation dark matter experiments selected for funding by DOE’s Office of High Energy Physics (HEP).

LZ involves a collaboration of 250 scientists, engineers and technicians from 38 institutions, including five U.S. National Labs. LZ expects to achieve a projected sensitivity level up to 100 times better than the final LUX search result for weakly interacting massive particles (WIMPs), the leading dark matter particle candidate.

Currently in the construction and installation phase, LZ is expected to begin operations in late 2019. The collaboration will perform a direct search for dark matter using 10 tonnes of liquid xenon within an ultra-pure titanium cryostat that will be surrounded by a new liquid scintillator veto system. The entire experiment will be immersed in a 72,000-gallon tank filled with ultra-pure water.

Neutrino science impacts

Beginning with Dr. Ray Davis’ groundbreaking neutrino research (1965-1992), the drifts at Sanford Lab are dedicated to refining knowledge about neutrinos and other research.

The Majorana Demonstrator Project has been collecting physics data since 2017. Recently published results are competitive with world-leading experiments and highlight the exceptional energy resolution and low backgrounds that have been achieved through the shielding offered at Sanford Lab.

The MJD project invested significant resources to produce the world’s purest copper. In parallel with ongoing MJD operations, specific elements—such as electronics upgrades and copper electroforming—are being pursued at Sanford Lab in the context of R&D for the next-generation neutrinoless double-beta decay experiment called the Large Enriched Germanium Experiment for Neutrinoless bb Decay (LEGEND). LEGEND-200 physics data collection is expected to begin in 2021. Extraordinary levels of material radiopurity will be required to reach the LEGEND-1000 background goal.

The work done at Sanford Lab, including depth and ultra-pure materials, have been instrumental in refining the search and preparing for the next generations.

223 acres
Surface footprint

The local footprint of the facility includes 223 acres on the surface. Facilities at both the Yates and Ross surface campuses offer researchers administrative support, office space, communications and education and public outreach. The Waste Water Treatment Plant handles and processes waste materials and a warehouse for shipping and receiving.

370 miles
Underground footprint
Of the 370 total miles of underground space, Sanford Lab maintains approximately 12 for science at various levels, including the 300, 800, 1700, 2000, 4100, and 4850 levels. The Davis Campus on the 4850 Level is a world-class laboratory space that houses experiment for neutrinoless double-beta decay and dark matter.

The CASPAR experiment, led by SD Mines, studies stellar nuclear fusion reactions, especially neutron production for slow neutron-capture nucleosynthesis (s-process). Accelerator components were relocated from the University of Notre Dame in 2015, and since the first beam in May 2017 and the first operations event in July 2017, accelerator commissioning has continued. Advanced commissioning data were obtained starting in February 2018 using the domain of interest for stellar CNO reactions.

“Researchers at CASPAR are engaging a community of researchers. Although Notre Dame and SD Mines are at the core, the collaboration continues to reach out to other research groups to build interest. One of the biggest impacts in South Dakota is the number of grad students participating in the Physics Ph.D. program in the state.” —Jaret Heise


Low-background counting impacts

The BHUC houses a low-background counting facility where components for physics experiments, including current and future Sanford Lab experiments, can be assayed. There has been significant interest in the BHUC low-background counting facility from many groups, including the Sub Electron Noise Skipper-CCD Experimental Instrument (SENSEI) experiment, which aims to search for low-mass dark matter using ~100 g of silicon CCD sensors, and the Germanium Internal Charge Amplification for Dark Matter Searches (GeICA) project.

Six high-purity germanium detectors are currently operating at the facility, with installation of an additional germanium detector expected in 2019. These low-background counters have been instrumental in characterizing materials for the LZ experiment for the past several years.

“The campus at Sanford Lab is an ideal location for these counters. Not only does its depth create a shield for the detectors, but it’s in the thick of major physics experiments—it’s where the action is.” —Kevin Lesko, senior scientist at Lawrence Berkley National Lab (Berkeley Lab) who manages the measurement and control of backgrounds

Geology research impacts

The SIGMA-V experiment, led by Lawrence Berkeley National Lab (Berkeley Lab), is a significant effort within the earth science field. SIGMA-V mobilized in October 2017, drilling a set of eight horizontal holes (each nearly 200 feet long) on the 4850L.

Members of the SIGMA-V experiment are continuing to explore enhanced or engineered geothermal systems (EGS) by building on results obtained from a previous experiment that was hosted at SURF between 2016 and 2017. Both groups drilled new holes as field demonstration sites in support of DOE flagship EGS effort called the Frontier Observatory for Research in Geothermal Energy (FORGE). SIGMA-V is testing the validation of thermal-hydrological mechanical-chemical (THMC) modeling approaches, as well as novel monitoring tools.

Biology opportunities

Important questions in life science, such as the conditions of life, the extent of life and ultimately the rules of life, are also being addressed underground at SURF. Generally, these programs have a small footprint in existing spaces and require only modest support from the facility. Biology researchers take full advantage of SURF’s footprint by gathering samples from a number of underground levels and areas with different temperatures and geologic mineralogies. Various groups focus on the diversity of life, including rock-hosted microbial ecosystems, and engineering applications such as improvements to biofuel production.


The Sanford Underground Research Facility offers a variety of environments in which engineers can test real-world applications and new technologies. And the rich history of the Homestake Mine, which includes a vast archive of core samples, allows engineers to better understand how to excavate caverns for new experiments.

Sanford Lab’s dedication to science, research and development and engineering, as well as its innovative approach to education, make it a world-leading science facility.

The Sanford Underground Research Facility supports world-leading research in particle and nuclear physics and other science disciplines. While still a gold mine, the facility hosted Ray Davis’s solar neutrino experiment, which shared the 2002 Nobel Prize in Physics. His work is a model for other experiments looking to understand the nature of the universe.

The Facility’s depth, rock stability and history make it ideal for sensitive experiments that need to escape cosmic rays. The impacts on science can be seen worldwide.

Our science as national priority

In 2014, the Department of Energy’s High Energy Physics Advisory Panel (HEPAP) committee prioritized physics experiments, giving neutrino and dark matter projects high-priority. Sanford Lab houses two of the five experiments named in the Particle Physics Project Prioritization Panel (P-5) Report: LUX-ZEPLIN (LZ) and LBNF/DUNE.

In 2015, a similar report done by the Department of Energy’s Nuclear Science Advisory Committee (NSAC) committee prioritized the ton-scale neutrinoless double-beta decay experiment, which aligns with the objectives of the Majorana Demonstrator Project.

International investment and cooperation

Sanford Lab hosts a variety of research projects in many disciplines. Researchers from around the globe use the facility to learn more about our universe, life underground and the unique geology of the region.

The site also allows scientists to share and foster growth within the science community and encourages cooperation between many countries and institutions.

We now have several hundred researchers from dozens of institutions around the world.

For example, for the first time in its history, CERN is investing in an experiment outside of the European Union with its $90 million commitment to LBNF/DUNE in the form of ProtoDUNE. The ProtoDUNE detectors have already recorded physics results. Additionally, the UK committed $88 million to the project.

CERN ProtoDune

Cern ProtoDune


Local impact

Building laboratory spaces deep underground at Sanford Lab created new opportunities for higher education in South Dakota. In 2012, the Board of Regents authorized a joint Ph.D. physics program at the South Dakota School of Mines and Technology in Rapid City and the University of South Dakota in Vermillion. Since then, dozens of students have participated in the program and worked on experiments at Sanford Lab. In 2017, each university saw their first students complete the program.

To date, there are 27 ongoing research projects housed at Sanford Lab, 24 of which include students and faculty from universities across South Dakota.

The Black Hills State University Underground Campus (BHUC) provides a space for students from across the state to preform interdisciplinary research underground. While physics students contribute to large-scale physics experiments by working in the low background counting facility, students from other disciplines can work on research in two areas adjoining the counting cleanroom.

“Biology students can study microbes in situ, and geology students can study the unique rock formations of the Black Hills,” said Briana Mount, director of the BHUC.

Additionally, a National Science Foundation (NSF) program, Research Experience for Undergraduates (REU), gives students from around the country, opportunities to pursue research through the underground campus.


Global footprint

Competition for underground laboratory space is fierce. With the completion of the Long-Baseline Neutrino Facility (LBNF) construction, Sanford Lab will host approximately 25 percent of the total volume of underground laboratory space in the world.

Surf-Dune/LBNF Caverns at Sanford

FNAL LBNF/DUNE from FNAL to SURF, Lead, South Dakota, USA

The sheer amount of space (7,700 acres underground) and existing infrastructure make the site highly attractive for future experiments in a variety of disciplines.

Global footprint depth

Sanford Lab is the deepest underground lab in the U.S. at 1,490 meters. The average rock overburden is approximately 4300 meters water equivalent for existing laboratories on the 4850 Level. The underground laboratory space has a strong track record of meeting experiment needs.


See the full article here .

Please help promote STEM in your local schools.

Stem Education Coalition

About us.
The Sanford Underground Research Facility in Lead, South Dakota, advances our understanding of the universe by providing laboratory space deep underground, where sensitive physics experiments can be shielded from cosmic radiation. Researchers at the Sanford Lab explore some of the most challenging questions facing 21st century physics, such as the origin of matter, the nature of dark matter and the properties of neutrinos. The facility also hosts experiments in other disciplines—including geology, biology and engineering.

The Sanford Lab is located at the former Homestake gold mine, which was a physics landmark long before being converted into a dedicated science facility. Nuclear chemist Ray Davis earned a share of the Nobel Prize for Physics in 2002 for a solar neutrino experiment he installed 4,850 feet underground in the mine.

Homestake closed in 2003, but the company donated the property to South Dakota in 2006 for use as an underground laboratory. That same year, philanthropist T. Denny Sanford donated $70 million to the project. The South Dakota Legislature also created the South Dakota Science and Technology Authority to operate the lab. The state Legislature has committed more than $40 million in state funds to the project, and South Dakota also obtained a $10 million Community Development Block Grant to help rehabilitate the facility.

In 2007, after the National Science Foundation named Homestake as the preferred site for a proposed national Deep Underground Science and Engineering Laboratory (DUSEL), the South Dakota Science and Technology Authority (SDSTA) began reopening the former gold mine.

In December 2010, the National Science Board decided not to fund further design of DUSEL. However, in 2011 the Department of Energy, through the Lawrence Berkeley National Laboratory, agreed to support ongoing science operations at Sanford Lab, while investigating how to use the underground research facility for other longer-term experiments. The SDSTA, which owns Sanford Lab, continues to operate the facility under that agreement with Berkeley Lab.

The first two major physics experiments at the Sanford Lab are 4,850 feet underground in an area called the Davis Campus, named for the late Ray Davis. The Large Underground Xenon (LUX) experiment is housed in the same cavern excavated for Ray Davis’s experiment in the 1960s.
LUX/Dark matter experiment at SURFLUX/Dark matter experiment at SURF

LBNL LZ project will replace LUX at SURF [see below]

In October 2013, after an initial run of 80 days, LUX was determined to be the most sensitive detector yet to search for dark matter—a mysterious, yet-to-be-detected substance thought to be the most prevalent matter in the universe. The Majorana Demonstrator experiment, also on the 4850 Level, is searching for a rare phenomenon called “neutrinoless double-beta decay” that could reveal whether subatomic particles called neutrinos can be their own antiparticle. Detection of neutrinoless double-beta decay could help determine why matter prevailed over antimatter. The Majorana Demonstrator experiment is adjacent to the original Davis cavern.

LUX’s mission was to scour the universe for WIMPs, vetoing all other signatures. It would continue to do just that for another three years before it was decommissioned in 2016.

In the midst of the excitement over first results, the LUX collaboration was already casting its gaze forward. Planning for a next-generation dark matter experiment at Sanford Lab was already under way. Named LUX-ZEPLIN (LZ), the next-generation experiment would increase the sensitivity of LUX 100 times.

SLAC physicist Tom Shutt, a previous co-spokesperson for LUX, said one goal of the experiment was to figure out how to build an even larger detector.
“LZ will be a thousand times more sensitive than the LUX detector,” Shutt said. “It will just begin to see an irreducible background of neutrinos that may ultimately set the limit to our ability to measure dark matter.”
We celebrate five years of LUX, and look into the steps being taken toward the much larger and far more sensitive experiment.

Another major experiment, the Long Baseline Neutrino Experiment (LBNE)—a collaboration with Fermi National Accelerator Laboratory (Fermilab) and Sanford Lab, is in the preliminary design stages. The project got a major boost last year when Congress approved and the president signed an Omnibus Appropriations bill that will fund LBNE operations through FY 2014. Called the “next frontier of particle physics,” LBNE will follow neutrinos as they travel 800 miles through the earth, from FermiLab in Batavia, Ill., to Sanford Lab.

Fermilab LBNE

U Washington Majorana Demonstrator Experiment at SURF

The MAJORANA DEMONSTRATOR will contain 40 kg of germanium; up to 30 kg will be enriched to 86% in 76Ge. The DEMONSTRATOR will be deployed deep underground in an ultra-low-background shielded environment in the Sanford Underground Research Facility (SURF) in Lead, SD. The goal of the DEMONSTRATOR is to determine whether a future 1-tonne experiment can achieve a background goal of one count per tonne-year in a 4-keV region of interest around the 76Ge 0νββ Q-value at 2039 keV. MAJORANA plans to collaborate with GERDA for a future tonne-scale 76Ge 0νββ search.

LBNL LZ project at SURF, Lead, SD, USA


CASPAR is a low-energy particle accelerator that allows researchers to study processes that take place inside collapsing stars.

The scientists are using space in the Sanford Underground Research Facility (SURF) in Lead, South Dakota, to work on a project called the Compact Accelerator System for Performing Astrophysical Research (CASPAR). CASPAR uses a low-energy particle accelerator that will allow researchers to mimic nuclear fusion reactions in stars. If successful, their findings could help complete our picture of how the elements in our universe are built. “Nuclear astrophysics is about what goes on inside the star, not outside of it,” said Dan Robertson, a Notre Dame assistant research professor of astrophysics working on CASPAR. “It is not observational, but experimental. The idea is to reproduce the stellar environment, to reproduce the reactions within a star.”