UK milestone brings DUNE neutrino detector closer to discovery

Imperial researchers are helping prepare giant detector panels for DUNE as the UK reaches a major production target.

Scientists and engineers across the UK have reached an important stage in the construction of the Deep Underground Neutrino Experiment (DUNE), an international project which will use one of the world’s largest neutrino detectors to investigate why matter dominates over antimatter in the Universe.

Half of the 137 Anode Plane Assemblies (APAs) being produced by the UK for DUNE’s Far Detector are now complete, marking significant progress towards the completion of the facility’s first detector module.  The giant detector panels will be used to sense neutrinos and are a key component of the facility’s first detector module.

Once complete, DUNE will send a beam of neutrinos from Fermilab in Illinois to the Sanford Underground Research Facility in South Dakota, 1,300 kilometres away. In doing so, scientists will be able to study how neutrinos change during their journey through the Earth. 

Known as neutrino oscillations, this phenomenon is one of the clearest signs that the Standard Model is incomplete. By making the most precise measurements of these oscillations to date, researchers hope DUNE could point the way towards new physics. 

The achievement comes at a significant moment for neutrino research. Earlier this month, the 2026 Nobel Prize in Physics recognised Francis Halzen’s leadership of the IceCube Neutrino Observatory, which transformed a cubic kilometre of Antarctic ice into a detector capable of observing high-energy cosmic neutrinos.

While IceCube uses neutrinos to study distant astrophysical phenomena, DUNE will focus on the particles themselves, measuring how they change as they travel and probing their fundamental properties.

Building DUNE’s giant detector panels

Among the UK’s flagship contributions to the experiment are the APAs. Standing more than six metres tall and 2.3 metres wide, each detector panel carries around 24 kilometres of fine copper-beryllium wire. These sense wires will record the faint electrical signals produced when neutrinos interact inside 10,000 tonnes of liquid argon.

The UK is responsible for producing 137 of the 150 APAs required for the experiment. They are assembled at STFC’s Daresbury Laboratory in partnership with researchers at Imperial and the Universities of Lancaster, Liverpool, Manchester, Sheffield and Sussex.

The Imperial team signing one of the beams that will be part of the DUNE cryostat at the SURF laboratory in South Dakota that will hold the liquid argon and the APAs.

Preparing APAs for the deep freeze

Imperial researchers are ensuring the detector components can operate reliably in the demanding conditions they will face once installed nearly a mile underground in South Dakota.

At CERN, the team tests completed APAs under conditions similar to those they will experience inside DUNE’s liquid argon detector. Using a custom-built “cold box”, researchers cool fully instrumented detector panels to temperatures of around -120 °C and monitor their performance throughout the process.

These tests are designed to confirm that the large wire frames remain mechanically stable at low temperatures and that the electronics used to read out detector signals continue to operate reliably.

Dr Philip Hamilton, from Imperial’s Department of Physics, explained “Getting an APA fully instrumented and into the cold is a complex operation. We've been testing APAs at CERN since 2023 and we're still learning a lot each time we test. The work we're doing here will help us put our best foot forward when it comes to installing all 150 APAs down the mine.”

The team is also responsible for checking the tension of all 3,520 wires on each APA before installation. Across all 150 APAs, this means verifying more than half a million wires before the detector begins operation.

Because the detector cannot be opened once it begins operating, every wire must be verified to ensure it meets strict performance requirements.

To do this, researchers use a Digital Wire Analyser (DWA), which applies electrical signals to make each wire oscillate. By measuring the resulting frequencies, the team can identify any broken, loose or over-tensioned wires, much like tuning a musical instrument.

They routinely test APAs when they arrive at CERN for cold tests and will test every wire on each of the 150 APAs before they are installed underground.

Dr Anyssa Navrer-Agasson, who leads the analysis of the DWA measurements at Imperial, said “Every single wire has to be checked, because once the APA goes inside the detector, there's no going back to fix it. The Digital Wire Analyser lets us catch any problems with the wires before installation, ensuring the APA will perform reliably for decades of operation.”

Looking ahead

While reaching the halfway point in production is a major achievement, substantial work still lies ahead. The remaining APAs will be completed over the coming years before being shipped to the United States for final testing and installation.

Professor Stefan Söldner-Rembold, former spokesperson for the international DUNE collaboration and leader of the experiment’s second phase, said “DUNE is one of the largest international projects in particle physics, with more than 1,800 collaborators from over 230 institutions worldwide.

As the detector moves from construction towards operation, we are delighted that Imperial will host the collaboration in September next year, bringing together researchers from across the globe to help shape the next phase of the experiment.”