AIT / WATCHMAN: Year One

The Advanced Instrumentation Testbed (AIT) is a new facility, to be sited in the Boulby Underground Laboratory, that aims to explore new technologies for the purposes of nuclear non-proliferation and particle physics. The first phase of AIT is the WATer CHerenkov Monitor for Anti-Neutrinos (WATCHMAN). WATCHMAN construction is primarily funded through the US National Nuclear Security Administration (NNSA). UK involvement is a partnership between our industrial partners in the Atomic Weapons Establishment (AWE), the STFC-Boulby laboratory, and the Universities of Sheffield, Edinburgh, and Liverpool.

The WATCHMAN detector is a technology demonstrator, which will attempt the first monitoring of nuclear reactors from a standoff distance of tens of kilometres. The mechanism for this monitoring is anti-neutrino detection. Nuclear reactions all produce a large flux of anti-neutrinos, which cannot be shielded. The WATCHMAN detector combines the decades-old technology of water Cherenkov neutrino detectors with the new technique of gadolinium loading. Adding gadolinium to the detector makes it sensitive to the neutron that is produced in an anti-neutrino interaction, but not a low-energy neutrino interaction. As such, the coincident signature of positron plus neutron can be used to tag anti-neutrinos.

If successful, the techniques pioneered by WATCHMAN could be used to search for clandestine nuclear reactors as a means of non-proliferation and nuclear threat reduction.

The AIT also includes a significant component of research and development into new detection materials and technologies. For this purpose, AIT will be investigating fast photosensors such as the Large Area Picosecond Photo-Detector (LAPPD), and new detector materials, such as water-based liquid scintillator. These can be used in future phases of the project to enhance the reactor detection range, as well as to enable particle physics goals such as geoneutrino studies and searches for neutrinoless double-beta decay.

First and foremost, WATCHMAN is an impact project. The primary sponsor is the US National Nuclear Security Administration, which has committed $33M of US funding for the construction of WATCHMAN. The technology demonstrated by WATCHMAN is aimed at field deployment in regions where it is felt there may be clandestine nuclear reactors. The main goal of this project is impact, using particle physics techniques developed over the past four decays, and re-purposing them for practical use. In this case, the impact goal is nuclear threat reduction and non-proliferation.

The primary non-proliferation impact case will be fully realised on the timescale of six years, following the construction phase and the exploitation phase. In the interim, there is also a secondary impact case, which is knowledge transfer. UK involvement in WATCHMAN is a partnership between the STFC-Boulby Underground Laboratory, the universities, and the Atomic Weapons Establishment (AWE). We are engaged in knowledge exchange with our industrial partners at AWE, which is a valuable impact case taking place now, during the four year construction phase of WATCHMAN.