The Deep Underground Neutrino Experiment detector features four massive modules, each containing 17,000 metric tons of liquid argon.


U.K. pledges $88 million to gigantic U.S. particle physics experiment

The United Kingdom has agreed to help build the next great particle physics experiment in the United States.

In a signing ceremony today at the U.S. Department of State in Washington, D.C., U.K. officials pledged to spend ₤65 million—roughly $88 million—on key components for the proposed Deep Underground Neutrino Experiment (DUNE), a particle detector located in a defunct gold mine in Lead, South Dakota. Last month, researchers began digging the four massive caverns that will house the gargantuan modular detector.

The agreement “involves us in one of the most exciting new physics experiments in the world,” Jo Johnson, U.K. minister for universities, science, research, and innovation, told ScienceInsider. “We’re delighted to be a part of it.”

Although the U.K. contribution represents a small fraction of the total cost of the experiment, its timing will have an outsized impact on the effort, which the United States is striving to internationalize, says Edward Blucher, a physicist at the University of Chicago in Illinois and co-spokesperson for the 1020-member DUNE collaboration. “It’s like any other investment,” he says. “The early investors give others confidence that the project will go forward.” Project officials hope to attract contributions from other nations in the next few years.

DUNE aims to decipher the properties of elusive subatomic particles called neutrinos. Nearly massless and hardly interacting with other matter, neutrinos come in three types—electron, muon, and tau—depending on the particle interactions in which they are born. As the particles zip along at near light-speed, they can change type, in a phenomenon known as neutrino oscillation. Since 1999, physicists in Japan, Europe, and the United States have studied such morphing by shooting neutrinos from particle accelerator labs to distant detectors.

DUNE aims to be the definitive accelerator-based neutrino experiment. Fielding neutrinos fired from 1300 kilometers away at Fermi National Accelerator Laboratory (Fermilab) in Batavia, Illinois, it would nail down the parameters in physicists’ theory of such oscillations and search for inconsistencies that could point to new physics. It would also compare the rates at which neutrinos and antineutrinos oscillate, looking for a difference that could help explain how the infant universe generated so much more matter than antimatter.

Researchers hope to begin building the DUNE detector in 2019 and complete it in 2024. But it is only one piece of the project. The rest—the neutrino beam at Fermilab, the infrastructure in South Dakota, and the cryostats that will hold 70,000 metric tons of liquid argon—are nominally parts of DUNE’s partner, the Long-Baseline Neutrino Facility (LBNF). LBNF/DUNE would be funded mainly by the U.S. Department of Energy, which envisions spending a total of $1.5 billion. That contribution would cover 75% of the cost of the LBNF and 25% of the cost of DUNE, Blucher says. DUNE itself will cost roughly $480 million, he says—nailing down the amount is difficult because the United States and other countries do their accounting differently. U.K. researchers will make key internal components for DUNE as well as parts of the data acquisition system, Blucher says.

Johnson notes that the United Kingdom’s contribution to DUNE will augment other activities in particle physics. The United Kingdom is the second largest contributor to the European particle physics laboratory, CERN, near Geneva, Switzerland, with an annual contribution of $175 million. Johnson says that commitment won’t be affected by the United Kingdom joining DUNE.