10 years of science

Lab celebrates banner year of activity, makes plans for expansion

B y W endy P itlick Black Hills Pioneer

LEAD — From its sought-after, world-renowned facility for underground science, to its award-winning education and outreach program, and its access to knowledgeable personnel and support services, the Sanford Underground Research Facility (SURF) has quickly made a name for itself across the world.

In 2022, SURF officials celebrated 10 years of science at the Davis Campus — where many of its key experiments are set up a mile underground to avoid cosmic radiation from the earth’s surface. In its first decade, the facility has secured its place as one of the premier locations for physics research, with a projected $2 billion economic impact on the state from 2020-29, and a spotlight on the world stage in the scientific community. Recently, the United States Particle Physics Community “strongly recommended” expansion at the 4850-level, to accommodate the next generation of experiments in dark matter, neutrinos, and other ground-breaking research projects that can only be conducted deep under the earth’s surface. SURF, as the United States’ only underground laboratory and one of the deepest in the world, checks all of the boxes scientists need for their research — depth, space, availability of environmental radiation monitoring, material screening capability, access for equipment and people, space for and availability of needed infrastructure and local support, and underground machine shops.

“SURF is recognized by the scientific community as a world-leading laboratory,” said Mike Headley, executive director of the S.D. Science and Technology Authority, which manages the lab. “Currently, the particle physics community is preparing a new 10-year strategic plan. They have strongly endorsed the future expansion of SURF to host an even broader suite of next-generation experiments.

“There are no competing interests at SURF,” Headley continued. “We are 100% dedicated to the science mission. Our scientists appreciate our focus on helping them be successful. We receive consistently positive feedback about the strong support they receive from the team.”

As officials with SURF look forward to hosting even more world-leading experiments across all disciplines of science, they are also focused on current projects, achievements, and educational opportunities. Currently the S.D. Science and Technology Authority, the managing entity for the lab, has 185 full time employees and 15 part time workers. There are also two employees from the Department of Energy on site, and about 20 employees from Fermilab. Additionally, the lab works with about 200 contractor employees that are at SURF full time.

Long Baseline Neutrino Facility

As of the beginning of this year, crews from Thyssen Mining have completed 56% of the excavation, having removed more than 400,000 tons of rock from the 4,850-level to prepare for the Long Baseline Neutrino Facility construction. Once complete, the space includes three large caverns. Two of them are 500 feet long, 65 feet wide, and 90 feet high. The third cavern will be 625 feet long, 65 feet wide, and 36 feet tall.

Patrick Weber, head of the Fermilab South Dakota Services Division said the Thyssen Mining team includes 145 staff members actively working on the excavation, including 115 people who work underground each day. The crew is on track to complete excavation by 2024. Once that is done, Weber said crews will start pouring concrete on the base of the caverns and on all the interconnecting drifts.

“Once the floors are cured, the team will begin the installation of all utilities necessary to support the detectors,” Weber said. “This includes electrical power distribution, lighting, fire alarms and suppression systems, communications, and air conditioning. At the same time, assembly of the large cryostats that house the detectors will begin as the first step in detector installation.”

Once the Long Baseline Neutrino Facility is complete, it will host the international Deep Underground Neutrino Experiment, which will have scientists shooting a beam of neutrinos from Fermilab in Illinois, through the earth to detectors set up deep underground at SURF. By doing this, scientists plan to study the properties of neutrinos, including how the subatomic particles change in transit, the mass of different neutrinos, and the imbalance of matter and antimatter in the universe. They hope to answer some of the most fundamental questions in physics today, including how the universe was created.

Science

Currently the Sanford Underground Research Facility is the host for 29 experiments that span multiple disciplines. This year, two of the largest experiments — the LUX-ZEPLIN (LZ) dark matter experiment and the Majorana Demonstrator — celebrated major milestones. The LZ established itself as the most sensitive dark matter experiment in the world. Majorana collaborators proved that the methodology and infrastructure for the experiment could be successfully used to build a larger detector to search for an extremely rare process called neutrinoless double beta decay, which could explain why there is more matter in the universe that antimatter. Additionally, scientists have repurposed the Majorana detector to switch gears and search for a rare isotope decay and conduct further dark matter research. Both experiments have been operating in the Davis Campus at the 4850 level for many years, and their announcements were considered major successes and advancements in the worldwide scientific community.

“When we started this project there were many risks and no guarantee that we could achieve our goals, as we were pushing into unexplored territory,” said John Wilkerson, principal investigator

10 Years Of Science

for Majorana and a physics professor at the University of North Carolina. “Today we’re one step closer to understanding the imbalance in the universe, and why we exist at all.”

Hugh Lippincott, spokesperson for the LZ experiment said his collaboration has only begun its groundbreaking work at SURF. “We plan to collect about 20 times more data in the coming years, so we’re only getting started,” he said. “There’s a lot of science to do and it’s very exciting.”

In addition to physics experiments, SURF is also the host for Caterpillar’s testing facility for underground tracking systems designed to keep miners and other workers safe while working underground, and to offer autonomous equipment operation. That work is being conducted at the 1700 Level.

Acoustic sensing technology, and microbial studies of lifeforms that make their home a mile beneath the surface of the earth are also examples of some of the latest research projects in the lab, along with many other projects.

Education and Outreach

During the 2021-22 school year, officials from the SURF Education and Outreach Department report that they helped support 700 teachers and reached more than 20,000 students. So far in the 2022-23 school year, the lab has reached out to 300 teachers and had an impact on 13,000 students.

SURF offers professional development services for teachers, school presentations, field trip opportunities and self-contained math and science curriculum modules with a goal to teach children in grades K-12 how to learn about STEM concepts, rather than what to learn.

In addition to working within the education system, officials with SURF have been working to engage Lead residents in the science and activities at the lab by hosting Deep Talks, a monthly public lecture series that features a wide array of lab topics. Sanford Lab Communications Director Constance Walter said each lecture attracts between 50 to 125 community members, and many more who attend virtually.

In 2021, the S.D. Science and Technology Authority acquired the Sanford Lab Homestake Visitor’s Center, with a goal to create a space that tells the history of the Homestake Mine, the story of the lab development, and to explain current science experiments at the lab. In 2022, Visitor’s Center Director Kelly Kirk said the facility hosted 54,000 visitors who enjoyed the displays, talked with scientists, and participated in a multitude of other educational activities. In just the first few months of 2023, the facility has already welcomed 1,500 visitors.

Headley said the emphasis on education and outreach to all members of the community is part of SURF’s mission to be a good neighbor.

“The citizens of Lead are our neighbors,” he said. “We feel strongly about participating in the community and working hard to minimize any impacts on our neighbors. It’s the right thing to do.”

SURF facility

While scientists and educators kept busy underground and in the community, S.D. Science and Technology operators were busy maintaining the facility. A major aspect of operations at the lab includes pumping and treating water from underground, and in 2022 Wastewater Treatment Plant foreman Ken Noren reported that more than 9 billion gallons of water had been treated.

“That’s the same as 13,686 Olympic swimming pools,” Noren said. “Or, you could think of it as one Olympic swimming pool being filled every eight hours since 2008.”

SURF crews also completed significant infrastructure repairs on the Yates Shaft. The timber-bracedshaft was shut down for about six months while crews stabilized weight-bearing beams and wall plates. Shutting down the shaft meant limiting some access to the underground lab space and using the for science and con - traffic. Crews worked around the clock to complete the work safely and efficiently, and in record time.

“It got a little crazy, and planning was key,” said Wendy

SURF. “We were able to get the work done safely and have that time we needed to really take a look at things and do the repairs that we needed to do. The guys did a terrific job.”

10 Years Of Science

Straub said the work was a learning experience for the entire crew, since there are not very many wooden shafts left in the world. Most mining shafts are made of steel, but the Yates Shaft was constructed during World War II, when steel was in short supply. In the future, Straub said replacing timber in the shaft with steel will likely become part of the lab’s long term facility plan.

“It’s such a fine art and everything has to go together just so, and there aren’t a lot of people left who know how those things work and how those things go together,” Straub said of the timber shaft.

Looking ahead

Gov. Kristi Noem’signed Senate Bill 35, which passed the Legislature with an overwhelming majority. The bill will give $13 million in emergency funding to expand the lab facilities to accommodate future experiments.

Headley said the support for the lab leading up to the vote was “amazing,” as he worked with them to explain the lab investment. To date, the state has contributed $62 million in appropriations and future funds. That initial invest - ment has resulted in $932 million in federal and private dollars that have paid for operations and projects. That means the state has received a return investment of 15 times.

The $13 million, officials say, will pay for Thyssen Mining crews to remain underground longer to start the expansion process by installing critical ventilation and rock removal infrastructure. Starting the expansion while Thyssen crews already have their equipment underground for the Long Baseline Neutrino Facility excavation saves about $15 million in mobilization costs. Lab officials say the projected $100 million in construction costs for the expansion will be raised with private donations. Philanthropist T. Denny Sanford, who previously invested $70 million at SURF, has already pledged to be at least one of those major donors for the expansion project.

“We’re out of space,” S.D. Science and Technology Authority Board Chair Casey Peterson told members of the Senate Commerce and Energy committee. “Recently two experiments have gone to Canada and Italy, taking U.S. dollars for research and experiments. That is unacceptable.”

“We are at a critical point right now,” said Mike Headley, executive director of the S.D. Science and Technology Authority. “If we want to grow and remain a world leader in science, we need to have more underground space in the United States. We are competing with the world’s best science labs in the world, and for that to continue, we have to expand. The science community has endorsed building more space at SURF.”

The planned expansion includes two caverns, each 100 meters long, 24 meters tall, and 20 meters wide. Each cavern could potentially host up to three experiments.