Excavation of colossal caverns for Fermilab’s DUNE experiment completed

The excavation of the caverns that will house the gigantic particle detectors of the Deep Underground Neutrino Experiment in Lead, South Dakota is complete. Final outfitting of the colossal caverns will begin soon and make way for the start of the installation of the DUNE detectors later this year.

Construction workers created two colossal caverns, each more than 500 feet long and about seven stories tall, for the gigantic particle detector modules of the Deep Underground Neutrino Experiment, hosted by Fermilab. A third cavern will house utilities for the operation of the detector. Photo: Matthew Kapust, Sanford Underground Research Facility

A bird’s eye view of one of the large caverns in South Dakota, about the height of a seven-story building. Large particle detectors for the Deep Underground Neutrino Experiment will be placed here to study the behavior of neutrinos. The DUNE detectors are expected to be the largest underground cryogenic system in the world. Photo: Matthew Kapust, Sanford Underground Research Facility

Lead, South Dakota, Feb. 01, 2024 (GLOBE NEWSWIRE) -- Excavation workers have finished carving out the future home of the gigantic particle detectors for the international Deep Underground Neutrino Experiment. Located a mile below the surface, the three colossal caverns are at the core of a new research facility that spans an underground area about the size of eight soccer fields.

Hosted by the U.S. Department of Energy’s Fermi National Accelerator Laboratory, 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 caverns provide space for four large neutrino detectors—each one about the size of a seven-story building (see 2-minute animation). The detectors will be filled with liquid argon and record the rare interaction of neutrinos with the transparent liquid.

Trillions of neutrinos travel through our bodies each second without us even knowing it. With DUNE, scientists will look for neutrinos and examine the behavior of a neutrino beam produced at Fermilab, located near Chicago, about 800 miles east of the caverns. This will be the world’s most intense neutrino beam and will travel straight through earth from Fermilab to the detectors in South Dakota. No tunnel is necessary for the neutrinos’ path.

“The completion of the excavation of these enormous caverns is a significant achievement for this project,” said U.S. Project Director Chris Mossey. “Completing this step prepares the project for installation of the detectors later this year and brings us a step closer towards fulfilling the vision of making this a world-class underground facility.”

 Engineering, construction and excavation teams have been working 4,850 feet below the surface since 2021 at the Sanford Underground Research Facility, home of the South Dakota-portion of DUNE. Construction crews dismantled heavy mining equipment and, piece by piece, transported it underground using an existing shaft. Workers then reassembled the equipment, and workers spent almost two years blasting and removing close to 800,000 tons of rock.  

Workers will soon begin to outfit the caverns with the systems needed for the installation of the DUNE detectors and the daily operations of the research facility. Later this year, the project team plans to begin the installation of the insulated steel structure that will hold the first neutrino detector. The goal is to have the first detector operational before the end of 2028.

“The completion of the three large caverns and all of the interconnecting drifts marks the end of a really big dig. With no lost-time accidents in over three years, we reached a major achievement,” said Fermilab’s Michael Gemelli, who managed the excavation of the caverns by Thyssen Mining. 

The DUNE collaboration, which includes more than 1,400 scientists and engineers from over 200 institutions in 35 countries, is eager to start the installation of the particle detectors. They have successfully tested the technology and assembly process for the first detector and preparations for the technology of the second detector is underway at the European research laboratory CERN.

Fermilab is America’s premier national laboratory for particle physics and accelerator research. A U.S. Department of Energy Office of Science laboratory, Fermilab is located near Chicago, Illinois, and operated under contract by the Fermi Research Alliance LLC. Visit Fermilab’s website at www.fnal.gov and follow us on Twitter at @Fermilab.

The DOE 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.

Tracy Marc
Fermilab
2242907803
TRACYM@FNAL.GOV