Completion of Massive Caverns Deep Underground for Neutrino Research

The Deep Underground Neutrino Experiment will measure neutrino oscillations by studying a neutrino that will be sent from Fermilab to the DUNE detectors at the Sanford Underground Neutrino Facility. The experiment will use a muon neutrino beam created at Fermilab’s Long-Baseline Neutrino Facility and send it 800 miles/1300 kilometers straight through the earth to South Dakota. By the time the neutrinos arrive in South Dakota, only a small fraction of neutrinos will be detected as muon neutrinos. Most neutrinos will interact as electron and tau neutrinos. Credit: Fermilab

The Sanford Underground Research Facility celebrated the completion of excavation for the LBNF/DUNE project, a major international endeavor led by Fermilab to explore the universe’s deepest questions using neutrino interactions.

With substantial international collaboration and significant technological challenges overcome, this project stands to make groundbreaking scientific advances.

Celebrating the Completion of SURF Excavation

A ribbon-cutting event was held today at the Sanford Underground Research Facility (SURF) in Lead, S.D. to mark the completion of excavation work for the Long-Baseline Neutrino Facility/Deep Underground Neutrino Experiment (LBNF/DUNE), an international project led by the U.S. Department of Energy’s Fermi National Accelerator Laboratory. The “Into the Depths of Discovery” event, hosted by Fermilab and the South Dakota Science and Technology Authority (SDSTA), was attended by supporters of the three-year excavation of the caverns, including state and federal leaders as well as Department of Energy officials.

DUNE SURF Ribbon Cutting — Fermilab Director Lia Merminga (center, left) and Sanford Underground Research Facility Director Mike Headley (center, right) cut the ribbon to mark the completion of the three-year excavation of the caverns for the Long-Baseline Neutrino Facility/Deep Underground Neutrino Experiment. Supporters and people instrumental in the project helping to hold the ribbon are (left to right): LBNF/DUNE-US Federal Project Director Adam Bihary, CERN Senior Scientist and Neutrino Platform Project Leader Francesco Lanni, DUNE Collaboration Co-spokesperson Sergio Bertolucci, President and CEO of Universities Research Association John Mester, Department of Energy Assoc. Director for the Office of High Energy Physics Gina Rameika, DOE Principal Deputy Under Secretary for Science and Innovation Derek Passarelli, DOE Chief of Staff of Secretary Jennifer Granholm Christopher Davis, Acting DOE Director of the Office of Science and Deputy Director for Science Programs Harriet Kung, South Dakota Lt. Gov. Larry Rhoden, U.S. Senator for S.D. Mike Rounds, U.S. Rep. for S.D. Dusty Johnson, University of Campinas Rector Antonio José de Almedia Meirelles, LBNF/DUNE-US Project Director Jim Kerby. Credit: Ryan Postel, Fermilab

“Today we celebrate this remarkable engineering feat and are grateful to the many people who worked to achieve this milestone,” said Derek Passarelli, DOE Principal Deputy Under Secretary for Science & Innovation. “This is an extraordinary achievement given the nature of the underground excavation. The LBNF/DUNE endeavor, involving partners from the nation as well as from around the world, will bring together our collective minds and talents focused on tackling the most challenging questions about how our universe works.”

The Deep Underground Neutrino Experiment is an international experiment to unlock the mysteries of neutrinos. DUNE will be installed in the Long-Baseline Neutrino Facility, under construction in the United States. The U.S. Department of Energy’s Fermilab is the host laboratory for DUNE, in partnership with funding agencies and more than 1,300 scientists and engineers from over 35 countries.

Exploring Neutrino Interactions and the Universe’s Mysteries

The event occurred one mile beneath the surface at the northern detector cavern and marked the completion of excavation work on two seven-story caverns for housing particle detectors (see 2-minute animation above), as well as a smaller central utility cavern. The two detectors will each be filled with 17,000 tons of liquid argon cooled to minus 184 degrees DUNE SURF Cavern

Two colossal caverns, each more than 500 feet long and seven-stories tall, were completed to contain the gigantic particle detector modules for the Long-Baseline Neutrino Facility/Deep Underground Neutrino Experiment, an international collaboration led by Fermilab. A third cavern will house utilities for the operation of the DUNE far detector. Credit: Ryan Postel, Fermilab

The Role of International Collaboration in Scientific Progress

“It is exciting to have so many people here today who have supported the excavation and construction of the project,” said Lia Merminga, director of Fermilab. “This is an important step in making LBNF/DUNE a world-class international underground science facility.”

The research conducted at Fermilab and SURF is the foundation for future technological innovation. The history of scientific research shows that discoveries made today have the potential to positively impact humanity for generations to come.

DUNE SURF Lia Merminga — A mile underground, Fermilab Director Lia Merminga (left) discusses the progress of the three caverns for the Long Baseline Neutrino Facility/Deep Underground Neutrino Experiment with Construction Coordinator Nathan Strasbaugh (right) on Thursday, August 15, 2024 in Lead, S.D. Credit: Ryan Postel, Fermilab

Future Prospects at America’s Underground Lab

“This important milestone is a great way to celebrate the world-class research, innovation, education, and economic opportunities happening here at America’s Underground Lab,” said Mike Headley, laboratory director at SURF and the executive director of the South Dakota Science and Technology Authority. “The research underway at SURF will extend well into this century; the impact of scientific advancements made here could last much longer. Our future is incredibly bright, and we are excited to help it unfold.”

Excavation of LBNF/DUNE Caverns — The excavation of LBNF/DUNE caverns requires the transport of about 800,000 tons of rock from a mile underground to the surface, and then transporting it to its final resting place in a former mining area known as the Open Cut. Credit: Fermilab

Engineering, construction, and excavation teams have worked 4,850 feet below the surface since 2021 at SURF to prepare the space needed for the experiment. Over 800,000 tons of rock were excavated and moved from underground to an expansive former surface mining area known as the Open Cut. In order to accomplish this feat, construction crews dismantled heavy mining equipment and, piece by piece, transported it underground. Workers then reassembled the machinery and have been blasting and relocating rock ever since.

Fermi National Accelerator Laboratory and the Sanford Underground Research Facility celebrate this massive construction milestone and kick off the next phase of this project. Credit: Sanford Lab

A Global Scientific Endeavor

The U.S. Department of Energy’s Fermi National Accelerator Laboratory and Sanford Underground Research Facility are working together for this international science project as part of a large collaboration comprised of more than 1,400 scientists and engineers from over 200 institutions in over 35 countries and the European Organization for Nuclear Research, known as