The proliferation of nuclear weapons is a global concern and most nations with nuclear arsenals are working to reduce their own stockpiles of nuclear weapons while discouraging non-nuclear nations from obtaining nuclear weapons. India is having problems obtaining some nuclear technology from other nations because of fear that the tech might be repurposed to help develop nuclear weapons. Saudi Arabia is seeking assistance in the construction of nuclear power reactors but U.S. rules against export of dual-use technologies to countries that might use that technology for nuclear weapons production are impeding deals involving U.S. nuclear technologies companies.
The United States and the United Kingdom are collaborating on a new joint program called the Advanced Instrumentation Testbed (AIT) which is dedicated to the development of tools that can help prevent nuclear proliferation. AIT is being sponsored by the National Nuclear Security Administration at the U.S. Department of Energy. The first project of AIT is the WATCHMAN antineutrino detector.
WATCHMAN will be built by the AIT consortium which consists or which consists of Lawrence Livermore and Brookhaven national laboratories, the United Kingdom’s Atomic Weapons Establishment, UC Berkeley, UC Davis, UC Irvine, Iowa State University, Penn State University, the University of Pennsylvania, the University of Michigan, the University of Hawaii and the University of Sheffield, U.K.
Physicists from the University of California, Davis are leading the WATCHMAN antineutrino detector project. The new detector will be constructed inside a closed potash mine near Boulby, Cheshire, in the U.K.
WATCHMAN is an acronym that stands for WATer Cherenkov Monitor of Antineutrinos. It is designed to detect antineutrino particles generated by the nuclear power plant at Hartlepool which is about fifteen miles from Boulby. Ultimately, the goal is to create detectors that can pick up antineutrino production much further away that might be related to nuclear weapons production. WATCHMAN will be the first system that utilizes a scalable water-based technology to remotely monitor the activity at a single nuclear reactor.
Neutrinos and antineutrinos are nuclear particles which have almost no mass and interact only weakly with other nuclear particles such as protons and neutrons. They can pass through the entire Earth without being stopped by interaction with normal matter. Neutrinos and antineutrino detectors are often located far underground where other types of nuclear particles from space will be screened out.
The WATCHMAN detector will be a cylinder about fifty-three feet tall and about fifty-three feet in diameter lined with thousands of photomultiplier tubes. It will be filled with purified water to which gadolinium has been added. Gadolinium can capture neutrons. When an antineutrino enters the cylinder and triggers the release of a neutron in the water, it will trigger a very small flash of light when the gadolinium absorbs the neutron.
The UC Davis group is working on the ultrafast photomultiplier technology and finding new materials that can capture neutrinos and antineutrinos. The group has worked on other projects involving neutrinos and antineutrinos. The team hopes to have the WATCHMAN detector running in 2023.
