Defence R&D Canada - Suffield has conducted research and development on nuclear methods for detection of
bulk explosives since 1994. Initial efforts were directed at confirmation of the presence of bulk explosives in
land mines and improvised explosive devices (IEDs). In close collaboration with a few key Canadian companies,
methods suitable for vehicle-mounted or fixed position applications and those suitable for person- or small robotportable
roles have been studied. Vehicle-mounted systems mainly employ detection of characteristic radiation,
whereas person-portable systems use imaging of back scattered radiation intensity distributions. Two key design
tenets have been reduction of personnel shielding by the use of teleoperation and custom design of sensors to
address the particular problem, rather than adapting an existing sensor to a problem. This is shown in a number
of recent research examples.
Among vehicle-mounted systems, recent research to improve the thermal neutron analysis (TNA) sensors,
which were put into service with the Canadian Forces in 2002, are discussed. Research on fast neutron analysis
(FNA) and associated particle imaging (API), which can augment or replace TNA, depending on the application,
are described. Monoenergetic gamma ray induced photoneutron spectroscopy is a novel method which has a
number of potential advantages and disadvantages over TNA and FNA. Sources, detectors and geometries have
been identified and modelling studies have suggested feasibility. Among person-portable systems, research on
neutron backscatter imaging and X-ray coded aperture backscatter imaging are discussed.