The Underground Construction Association has awarded the Long-Baseline Neutrino Facility/Deep Underground Neutrino Experiment at the Sanford Underground Research Facility located in South Dakota, the prestigious 2026 Project of the Year Award. Hosted by the U.S. Department of Energy’s Fermi National Accelerator Laboratory, DUNE is a cutting-edge neutrino experiment comprised of three massive caverns located a mile below the surface. The underground space will house massive detectors and an entire laboratory system dedicated to neutrino research.
“The dedicated engineering teams who designed, excavated and constructed the colossal caverns in South Dakota, completed the project successfully and with an impeccable safety record,” said Fermilab Director Norbert Holtkamp. “Congratulations to the design and construction teams who achieved this important milestone. Construction of a project like this has never been done before in the U.S. They have my deep appreciation as we move to the next phase of making the underground laboratory a reality.”
LBNF won the award for a project in the $100M – $500M category. The construction teams of the LBNF/DUNE project included engineers from Arup, Delve Underground, Fermilab, Kiewit-Alberici Joint Venture, SURF and Thyssen Mining, Inc. Together, they pushed the limits of geotechnical engineering with the formation of two massive caverns, each measuring 65-feet wide, 92-feet tall, and 495-feet long (20 meters x 28 meters x 150 meters). The three caverns of the new research facility span an underground area close to the size of eight soccer fields.
“The dedicated engineering teams who designed, excavated and constructed the colossal caverns in South Dakota, completed the project successfully and with an impeccable safety record.”
Fermilab Director Norbert Holtkamp
For Mike Headley, the executive director of the South Dakota Science and Technology Authority and laboratory director at SURF, this award was made possible thanks to more than two decades of visionary leadership, generous philanthropy and dedicated labor.
“I think this UCA award is tremendous in that it recognizes the monumental scale of this project,” Headley said. “Building something like this on the surface would be challenging enough; it’s so impressive that through the cooperation of multiple partners, we have this enormous accomplishment nearly a mile underground,” Headley said of the project’s safety record; SURF logged more than one million hours during construction without a lost-time incident.
“The UCA Project of the Year Awards are presented to a project team or group that demonstrates insight and understanding of underground construction or a significant project, which may include practices, developing concepts, theories or technologies to overcome unusual problems within a project, resulting in little to no outstanding issues.”
Excavation work at the far site began in early 2019 and was completed in February 2024. During that time, the underground spaces were prepared for the DUNE project with the restoration and expansion of historic rock-handling systems that removed over 800,000 tons of rock from approximately 5,000 feet (1,520 meters) below ground. The rock traveled up the renovated mile-deep Ross shaft at SURF, continuing along an above-ground three-quarter-mile-long conveyor to a large former mining area called the Open Cut. LBNF consists of three long cut-out caverns; two of the caverns will house two far detector modules each, placed end-to-end, while the third will house cryogenics equipment and other utilities that keep the powerful detectors running.
Excavation successfully concluded with the stellar safety record of 1,135,105 hours worked without any lost-time injury.
DUNE scientists will study the behavior of mysterious particles known as neutrinos to solve some of the biggest questions about our universe. Why is our universe composed of matter? How does an exploding star create a black hole? Are neutrinos connected to dark matter or other undiscovered particles? The project is the largest neutrino collaboration in history and consists of more than 1,500 scientists and engineers from over 35 countries.
Fermi National Accelerator Laboratory is America’s premier national laboratory for particle physics and accelerator research. Fermi Forward Discovery Group manages Fermilab for the U.S. Department of Energy Office of Science. Visit Fermilab’s website at www.fnal.gov and follow us on social media.
When Steven Gardiner first embarked on his scientific career, his research centered on the practical applications of nuclear physics, such as prototyping neutron detectors for counterterrorism and improving simulations used by nuclear engineers to design reactors. Fundamental research on neutrino physics was far from his mind until he considered PhD programs and heard about the Deep Underground Neutrino Experiment, hosted by the U.S. Department of Energy’s Fermi National Accelerator Laboratory.
After speaking to his adviser, Bob Svoboda at University of California, Davis, about the exciting science potential of DUNE, Gardiner recalled, “I became a neutrino person and never looked back.” He joined Fermilab in 2018, bringing a unique background in neutron simulations to the study of some of the most elusive particles in the universe.
This career track recently earned Gardiner a Department of Energy Early Career Award, which provides funding to explore the low-energy research potential of DUNE. While the experiment is primarily designed for high-energy beam physics, Gardiner is advocating for its use as an unusual kind of telescope. Rather than collecting rays of light to study the universe, DUNE will be sensitive to ghostly low-energy neutrinos coming from outer space, including those from the Sun, supernovae, black holes and possibly dark matter.
“Even though DUNE is designed for beam physics, you can go way lower in energy, and it still performs,” Gardiner said. He believes his specific background allows him to make a “unique contribution due to my career trajectory,” taking him from neutrons to neutrinos.
The technical heart of this research involves upgrading a computer simulation code called MARLEY, or Model of Argon Reaction Low Energy Yields. Because neutrinos interact so weakly with ordinary matter, they are not directly visible in detectors. Instead, physicists must look for extremely rare collisions between neutrinos and atomic nuclei. Like a subatomic version of a car crash investigation, the tracks left by particles coming out of each collision provide clues about what originally happened. To put these puzzle pieces back together, scientists rely on detailed simulations of the collision physics, which is where MARLEY becomes essential. Results from these simulations will help researchers tell the difference between uninteresting noise, low-energy cosmic neutrinos and potential signals from undiscovered new particles. The ultimate goal of this work is to push the boundaries of physics. “My hope is that as a result of this project, we are thinking about new physics beyond the Standard Model,” Gardiner said.
He also emphasized science opportunities going far beyond the microscopic world. “Neutrinos reveal the inner workings of stars to us, whether it’s the core of our own Sun or the first moments of a supernova explosion,” Gardiner said. By refining the models used to interpret neutrino interactions, he is helping to open a wider view of the distant universe. “DUNE is a new window to the cosmos,” he said. “It gives us a new way of seeing into a hidden world where all kinds of crazy stuff might be going on.”
The DOE funding ensures that low-energy neutrino research may expand our understanding of the fundamental building blocks of the universe through the unparalleled sensitivity of the DUNE detectors.
Fermi National Accelerator Laboratory is America’s national laboratory for particle physics and accelerator research. Fermi Forward Discovery Group manages Fermilab for the U.S. Department of Energy Office of Science. Visit Fermilab’s website at www.fnal.gov and follow us on social media.
For nearly a century, scientists have been searching for evidence of dark matter, an invisible substance they believe makes up most of the mass of the universe. Such a discovery could lead to a greater understanding of our universe and how it works.
But finding this elusive material is easier said than done. For one thing, nobody knows exactly what dark matter is made of, so the range of particle masses and their signal frequencies is incredibly broad. Also, dark matter interacts infrequently with ordinary matter and light. To observe it, scientists rely on extremely sensitive detectors to capture very weak signals produced by dark matter particles.
In a study published in Physical Review Letters, scientists at Fermi National Accelerator Laboratory, University of Chicago, Stanford University and New York University used a state-of-the-art detector to speed up the search for one theorized dark matter particle — the dark photon — with unprecedented precision. If it exists, the dark photon would be distantly related to the photon, a visible particle of light.
Their research is enabled by the U.S. Department of Energy’s Quantum Information Science Enabled Discovery program, which partners Fermilab and university scientists to advance quantum sensor development for future high-energy physics experiments.
“Fermilab’s longstanding expertise in designing and building ultrasensitive, low-noise electronics makes it the ideal place to further this technology for next-generation quantum science research like dark matter searches,” said Aaron Chou, a scientist at Fermilab who worked on the study.
The dark photon resides in a narrow frequency band, which means to see its signal a radio-like detector must be carefully tuned to its exact frequency. Scientists developed this detector to be capable of capturing weak signals from dark photons by placing an electrically-tunable instrument called a superconducting quantum interference device — or SQUID — inside a three-dimensional microwave cavity. The device’s superconductance means it has no resistance to energy and can therefore pick up even the faintest signals, such as those from a dark photon.
Key to the detector’s ability to speed up the search for a tiny signal in a broad range of frequencies is flux tuning, which uses electricity to tune the device instead of manually.
“Rather than physically turning a dial to a specific frequency like with a radio, we apply electromagnetic flux to the SQUID, precisely controlling its ability to oppose changes in electricity flowing through it,” said Fang Zhao, a former Fermilab postdoctoral researcher who led the study.
Somewhat like an electronic pendulum, this flux essentially changes how quickly or slowly the device moves. The microwave cavity is coupled to the SQUID, so changes in the SQUID correspondingly changes the speed of the cavity, allowing it to “listen to” different frequencies.
“Without the ability to electrically tune its frequency, you would have to build billions of detectors to capture the signal,” said Ziqian Li, a former University of Chicago graduate student who also worked on the study. “In contrast, we can build a few flux-tunable detectors and place them at various frequencies, enabling capture of possible signals much faster than before.”
Conventional tunable detectors require mechanically changing the shape of a cavity by physically exerting force or adding mechanical parts inside connected circuits. This poses a challenge because qubit-based detectors require ultracold temperatures to function properly, and extreme cold can cause these parts to seize and break. In addition, mechanical parts emit a lot of heat, which creates noise in the cavity, obscuring signals and decreasing the ability to read and understand the quantum information stored inside the detector.
But use of flux tuning not only enables rapid frequency scanning, it also generates very little heat. This overcomes a major challenge for dark matter searches — preserving coherence. Quantum coherence, says Zhao, is what makes these sensors so precise.
“It’s a fundamental requirement for quantum devices to be protected from anything like heat or noise that might obscure such fragile signals and preserve them long enough for us to detect them.”
The scientists scanned a relatively large frequency range of 22-megahertz over three days. During this time, they were able to speed up the scanning rate by at least a factor of 20 over mechanical tuning methods. While their search did not turn up any dark photons, they were able to build on previous studies at multiple institutions and narrow the frequency range where dark matter can exist.
“What we’re really trying to do is to build a detector that is more sensitive than anybody else has ever made before; we did that,” said Chou. “We also showed that the detector was compatible with the qubit-based signal readout that we use for dark matter searches and that everything was integrated and everything just worked. It laid the foundation for larger dark matter searches.”
The current detector is very simple, with one cavity and one tunable device — the SQUID. However, work is underway to scale up this technology. Researchers could combine 10, 50 or even more cavities, each covering a different frequency range, with a single tunable element and simultaneously scan a 50 times wider range.
“While there is more work to do to improve scaling, we know now we can use the same detection technique to allow us to detect a large range of the dark photon within a few days, and then the full coverage search of the dark photon is within our reach,” said Li.
Fermi National Accelerator Laboratory is supported by the Office of Science of the U.S. Department of Energy. The Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time. For more information, please visit science.energy.gov.