Geneva, 10 November 2026 – Installation crews with the U.S. Department of Energy’s (DOE) Fermi National Accelerator Laboratory (Fermilab) and CERN, the European Laboratory 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 1.5 kilometres 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 tonnes of liquid argon maintained at approximately −185 °C.

“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 1300 km through the 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 1500 researchers hosted by Fermilab, including five DOE Office of Science Laboratories. The more than 6200 tonnes 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 in Rapid City, from Houston, of steel for both cryostats, and 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 that CERN has made such significant contributions to an experiment happening outside Europe.

“Collaboration is in CERN’s DNA, and our contribution to DUNE is a brilliant example of cross-organisational 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 ProtoDUNEdetector, 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 66 metres long, 19 metres wide and 18 metres high. 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 1478 metres 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 2600 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 under way 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 realising 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.”

DUNE’s underground space is planned to be completed by 2029, and the detector apparatus by 2030. From 2030, a worldwide team of 1800 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, launching DUNE’s long-term scientific programme.

Further resources:

Images:
- https://cds.cern.ch/record/2884532?ln=en
- https://cds.cern.ch/record/2858342?ln=en
- https://cds.cern.ch/record/2855567?ln=en

Videos:
- https://videos.cern.ch/record/3027278
- https://videos.cern.ch/record/2677463
- https://videos.cern.ch/record/2298023

Fermilab DUNE media kit: https://cernbox.cern.ch/s/O9jxNLOU5XrUqcg