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Kathryn Hartling
Canadian Nuclear Laboratories(CNL)

Abstract

An overview will be presented of several on-going research projects at Canadian Nuclear Laboratories (CNL) involving the application of muon, gamma, and liquid argon detectors for nuclear security and forensics, as well as contributions to Ac-225 medical isotope production.

Muon tomography leverages naturally-occurring cosmic-ray muon radiation to image target structures. CNL is currently home to four types of muon detectors based on plastic scintillators or Micromegas, including variants that are field deployable or integrate momentum measurement. In a nuclear security context, muon tomography can be used to identify and characterize special nuclear materials or associated shielding structures to support border security as well as nuclear waste management, disarmament, and infrastructure monitoring.

Nuclear forensics examines nuclear or radioactive materials, or other materials contaminated with radionuclides, in the context of legal proceedings. In this field, gamma-ray spectroscopy is a valuable method of characterizing the isotopic composition of materials in a non-destructive way. Coincident-gamma systems can help to isolate isotopic signatures in complex mixtures or high-background measurements. CNL is currently engaged in the development of a field-deployable coincident-gamma detector based on an array of cadmium zinc telluride crystals.

Liquid argon detectors are commonly used in dark matter and neutrino detection experiments, where it has been shown that they can provide excellent discrimination of nuclear and electron recoils. Consequently, LAr detectors are capable of detecting and differentiating neutron and gamma/beta radiation, and it is expected that their efficiencies and gamma energy resolution can exceed current standards for radiation portal monitors deployed for border security. CNL has developed a bench-top LAr detector prototype, and is currently planning for a future field-deployable design.

Ac-225 is a popular medical isotope candidate for targeted alpha therapy, a developmental method of cancer treatment. However, clinical trials are challenging due to low global production of this isotope. CNL is one of only a few locations globally with the ability to produce this material in research scale quantities. Ac-225 is produced by a thorium generator at CNL's Chalk River site, and by cyclotron irradiation of Ra-226 in collaboration with the Sylivia Fedoruk Canadian Center for Nuclear Innovation and Isotope Technologies Munich.

Timbits, coffee, tea will be served in STI A before the colloquium.