conceptual drawing of the Watchman antineutrino detector

A cutaway view of the Watchman antineutrino detector. (Credit: The support structure conceptual design and these drawings were created by Jim Brennan of Sandia National Laboratories, California branch)

The first-ever detection device to remotely monitor nuclear reactors is being designed and built by universities and laboratories around the world including researchers from the University of Hawaiʻi at Mānoa. When finished, the device offers great potential in the study of celestial events like supernovae, exploding stars that jettison millions of neutrinos into space.

“This new international project presents a great step toward major new large neutrino detectors, which will monitor nuclear activities and can simultaneously do interesting and possibly very dramatic physics and astrophysics explorations,” said John Gregory Learned, a UH physics and astronomy professor who has been influential in advancing the science and technology for long-range neutrino scanning for more than 16 years.

Neutrinos and their antimatter cousins, antineutrinos, are subatomic particles produced by stars, like the Sun, supernovae, nuclear reactors and radioactive materials.

The collaborative project, called Watchman, was announced on March 27 by the Lawrence Livermore National Laboratory in England and is sponsored by the National Nuclear Security Administration with the U.S. Department of Energy. The U.S. is contributing more than $30 million to build an antineutrino detector in a mine in England.

The device could detect undeclared nuclear reactors and monitor nonproliferation agreements aimed at preventing the spread of nuclear weapons.

In addition, Learned said one of the most exciting potential discoveries could come through detailed observation of a galactic supernova in neutrinos. “UH was a major participant in the only previous supernova neutrino observation in 1987, and we can only await the next arrival of a wave of neutrinos,” he said.

Learned added that the UH group possesses “special technical expertise, unique in the world’s elementary particle physics community, which will be utilized in this venture, further strengthening our status as one of the world’s preeminent neutrino research groups.”

Other UH researchers involved in the project are: Stephen Dye, UH physics and astronomy professor and chairman of the Institutional Board of Watchman who has been involved for more than 10 years; Assistant Professor Kurtis Nishimura and Professor Gary Varner, who run the Instrument Development Laboratory at UH and Jelena Maricic, associate professor of physics and astronomy, who has built specialized calibration hardware for similar detectors.

For more on the project, go read the Lawrence Livermore National Laboratory news release

Boulby mine

Boulby potash, polyhalite and salt mine on the northeast coast of England is Great Britain’s deepest mine and the home of the Science and Technology Facilities Council’s Boulby Underground Laboratory. The mine, operated by ICLUK /Cleveland Potash Ltd, is expected to be the site of the Advanced Instrumentation Testbed project, a new international multi-laboratory and university collaboration for nonproliferation research. The Watchman detector would be placed in an excavated cavern at the Boulby site and is slated to become operational in approximately 2023. (Photo credit: Science and Technology Facilities Council Boulby Underground Laboratory)