Excavation Completed for Gigantic Particle Detectors in Deep Underground Neutrino Experiment
Excavation workers have recently completed the monumental task of carving out the underground home for the gigantic particle detectors that will be used in the international Deep Underground Neutrino Experiment (DUNE). This groundbreaking research facility, located a mile below the surface, spans an area about the size of eight soccer fields.
The construction workers at Fermilab, hosted by the U.S. Department of Energy, have created two colossal caverns, each measuring over 500 feet long and standing at about seven stories tall. These caverns will house the massive particle detector modules for the DUNE experiment. Additionally, a third cavern has been constructed to accommodate the utilities necessary for the operation of the detector.
DUNE scientists aim to study the behavior of neutrinos, enigmatic particles that hold the key to answering some of the most significant questions about our universe. These questions include why our universe is composed of matter, how black holes are created by exploding stars, and whether neutrinos are connected to dark matter or other yet-to-be-discovered particles.
The caverns have been meticulously designed to provide ample space for four large neutrino detectors, each comparable in size to a seven-story building. These detectors will be filled with liquid argon and will record the rare interactions between neutrinos and the transparent liquid.
Neutrinos, which pass through our bodies unnoticed at an astonishing rate of trillions per second, will be studied using DUNE. Scientists will search for neutrinos emitted by exploding stars and analyze the behavior of a beam of neutrinos produced at Fermilab, located near Chicago. Remarkably, these neutrinos will travel straight through the earth and rock from Fermilab to the DUNE detectors in South Dakota, eliminating the need for a tunnel along their path.
U.S. Project Director Chris Mossey expressed his excitement about the completion of the excavation, stating, “The completion of the excavation of these enormous caverns is a significant achievement for this project. Completing this step prepares the project for installation of the detectors starting later this year and brings us a step closer towards fulfilling the vision of making this world-class underground facility a reality.”
The construction and excavation teams have been diligently working 4,850 feet below the surface since 2021 at the Sanford Underground Research Facility in South Dakota. They dismantled heavy mining equipment and transported it underground piece by piece using an existing shaft. Once underground, the equipment was reassembled, and workers spent nearly two years blasting and removing rock. In total, close to 800,000 tons of rock were excavated and transported from underground to an expansive former mining area above ground known as the Open Cut.
The next phase of the project will involve outfitting the caverns with the necessary systems for installing the DUNE detectors and ensuring the smooth operation of the research facility. Later this year, the project team plans to begin installing 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.
Fermilab’s Michael Gemelli, who managed the excavation of the caverns by Thyssen Mining, commended the exemplary safety record maintained throughout the project, stating, “The completion of the three large caverns and all of the interconnecting drifts marks the end of a really big dig. The excavation contractor maintained an exemplary safety record working over a million hours without a lost-time accident. That’s a major achievement in this heavy construction industry. The success of this phase of the project can be attributed to the safe, dedicated work of the excavation workers, the multi-disciplined backgrounds of the project engineers, and support personnel. What a remarkable achievement and milestone for this international project.”
The DUNE collaboration, consisting of over 1,400 scientists and engineers from more than 200 institutions across 36 countries, is eager to begin the installation of the particle detectors. The technology and assembly process for the first detector have been successfully tested, and mass production of its components has already commenced. Furthermore, testing of the underlying technologies for both detectors is currently underway using particle beams at the European laboratory CERN.
Fermilab, America’s premier national laboratory for particle physics and accelerator research, operates under the U.S. Department of Energy Office of Science. Located near Chicago, Illinois, Fermilab is dedicated to pushing the boundaries of scientific knowledge in the field of particle physics. For more information about Fermilab, visit their website at www.fnal.gov and follow them on Twitter at @Fermilab.
The DOE Office of Science, as the largest supporter of basic research in the physical sciences in the United States, is committed to addressing some of the most pressing challenges of our time. To learn more about their work, please visit science.energy.gov.
