Fermilab and CERN Begin Installation Work on DUNE Neutrino Experiment

Insider Brief

• Fermilab, CERN and the Sanford Underground Research Facility have begun installing the steel structures for the two massive cryostats that will house the Deep Underground Neutrino Experiment’s (DUNE) far detectors.
• Each cryostat will hold approximately 17,000 tons of liquid argon, with the experiment designed to study neutrinos sent 1,300 kilometres from Fermilab to detectors nearly a mile underground in South Dakota.
• The underground facility is expected to be completed by 2029, with detector installation scheduled for 2030 and the long-distance neutrino beam expected to begin operating by 2031.

PRESS RELEASE — Installation crews with the U.S. Department of Energy’s (DOE) Fermi National Accelerator Laboratory (Fermilab) and CERN, the European Organization for Particle Physics, are working alongside the Sanford Underground Research Facility (SURF) to begin building massive cryostats, giant insulated containers designed to hold liquid argon at an extremely cold temperature, for the leading-edge Deep Underground Neutrino Experiment (DUNE).

The work is happening nearly a mile underground at SURF in Lead, South Dakota, where thousands of red steel beams were meticulously transported, one by one, from the surface down to the assembly area. Once installed, the beams will form the outer structures of the experiment’s two detector module cryostats. Each will house approximately 17,000 tons of liquid argon maintained at approximately minus 300 degrees Fahrenheit.

“DUNE is Fermilab’s top priority,” said Norbert Holtkamp, director of Fermilab. “The entire organization is thrilled to see this work begin. Once underway, DUNE has the potential to help us broaden our fundamental understanding of our universe, as well as potentially open the door to new technological advances.”

Once operational, Fermilab will send a beam of neutrinos 800 miles (1,300 kilometers) through Earth to DUNE’s liquid-argon detectors in South Dakota. A second detector near the neutrino beam source at Fermilab will measure the particles before they begin their journey. Together, the facilities at Fermilab and the underground site in South Dakota form the Long-Baseline Neutrino Facility.

DUNE is an international collaboration of over 1,500 researchers hosted by Fermilab, including five DOE Office of Science Laboratories. The more than 6,200 tons of steel being used on the cryostat modules are an in-kind contribution from CERN. CERN is leading the design, construction planning, logistics and installation of DUNE’s massive cryostats, working with a Minnesota-based structural steel contractor to assemble the structures deep underground in South Dakota.

“We have been lucky to see several milestones occur recently, such as the arrival of steel for both cryostats in Rapid City from Houston, to the celebration earlier this year marking the start of steel being lowered underground in Lead,” said Jolie Macier, project manager for the far detectors and cryogenics of DUNE. “This brings us one step closer to science.”

The DUNE experiment marks the first time CERN has made such significant contributions to an experiment happening outside of Europe. 

 “Collaboration is in CERN’s DNA, and our contribution to DUNE is a brilliant example of cross-organizational partnership,” said Mark Thomson, director general of CERN. “After years of planning and careful coordination, I am thrilled to see that we are ready to start installation.” 

CERN is a leader in particle physics technologies, including the design of the unique cryostats for DUNE. Using its Neutrino Platform facility, CERN developed and built the ProtoDUNE detector, the first prototype of the two detector technologies that will be used in the DUNE far detector modules.

“The work that has been done is a full contribution of CERN’s expertise,” said Lluís Miralles, Neutrino Platform principal project engineer at CERN. “Not only did we contribute our technical know-how, but also the project management capabilities of the organization. CERN demonstrates here how, by design, we have in-house competencies to address requirements and challenges at all levels of the project.”  

Each cryostat measures 216 feet long (65.8 meters), 62 feet wide (18.9 meters) and 60 feet high (18.3 meters). To illustrate the enormous size of the cryostats, each one is longer than a Boeing 747 airplane, and each one will stand a full story taller than the iconic Hollywood sign in Los Angeles. 

“SURF is proud to support this world-class research 4,850 feet (1,478 meters) below ground level. This massive experiment is slated to run into the late 2040s, with the potential to impact science for generations. In the process, it’s creating a home for some of the best and brightest scientific minds in the world and a range of high-paying jobs right here in the Black Hills,” said Mike Headley, SURF laboratory director and executive director of the South Dakota Science and Technology Authority. 

A total of 2,600 red steel beams will be used to build DUNE’s two cryostat modules. SURF is responsible for shaft operations and logistics, ensuring that each of these steel beams – and other necessary installation equipment – is safely transported underground to the work site. 

In addition to the installation work underway in the South Cavern, SURF crews have begun lowering steel components for the second cryostat into the North Cavern, where assembly is expected to begin next year.

“This marks an incredible milestone for the collaboration and reflects the cross-continental partnerships between CERN, Fermilab, and SURF that are essential to realizing this project,” said Sowjanya Gollapinni, co-spokesperson for DUNE. “This synergy is at the core of how big international collaborations work. We are thrilled to take this major step forward as we move closer to the transformative science that DUNE will deliver.”

The underground space of DUNE is planned to be completed by 2029, and the detector apparatus in 2030. From that date, a 1,500-strong worldwide team of researchers will begin probing the laws of nature more deeply than ever before, observing particles from the Sun and outer space. Using Fermilab’s PIP-II accelerator upgrade, the terrestrial neutrino beam is expected to be sent to the underground detectors in South Dakota by 2031, enabling DUNE’s long-term scientific program.

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.