Colloquium: Novel Detector Technologies for Nuclear Security and Non-proliferation

Speaker

Dr. Evan Rand, Canadian Nuclear Laboratories

Abstract

In this talk, two emerging technologies for nuclear security and non-proliferation applications which are actively being developed at Canadian Nuclear Laboratories (CNL) will be discussed. The first technology leverages the naturally occurring cosmic-ray muon background for the non-destructive testing of objects, such as shipping containers, large infrastructure, and spent nuclear fuel monitoring. Detecting shielded nuclear material is a difficult task with passive neutron and gamma-ray detectors. Muons, on the other hand, are highly penetrating and cannot be easily shielded, making them particularly attractive for imaging objects of various size, shapes, and geometry. Muon scattering tomography can provide information on the arrangement of objects within closed containers, detect voids, and determine the presence of high-density high-Z materials such as uranium or plutonium. Moreover, a newly developed non-parametric dense object detection algorithm, which doesn’t rely on imaging, shows promising results. The positive detection of high-density high-Z materials can be reduced to a few minutes for most objects, enabling other applications such as nuclear disarmament verification.

The second technology to be presented builds on advancements in noble liquid scintillator technology developed for the DEAP-3600 experiment - a state-of-the-art dark matter detector located 2 km below the surface of the earth at the SNOLAB facility in Sudbury, Ontario. The detector is comprised of 3600 kg of liquid argon (LAr) and is housed within a large ultra-pure water tank which serves as a radiation shield and a Cerenkov veto detector for cosmic-ray muons. CNL is adapting this same technology for the identification of special nuclear materials (SNM) at border crossings via fast neutron and gamma-ray detection. Conservative estimates using Monte Carlo simulation suggest that a 12 kg LAr detector could outperform a conventional helium-3 neutron detector by a factor of ~2 to 3 at spontaneous fission neutron energies of ~2 MeV.