Abstract:
The threat of a material is caused by its chemical, biological, radiological or nuclear (CBRN) properties. Radiological materials can be identified by the type and intensity of their emitted penetrating radiation. However, some radiation (alpha and beta) hardly penetrates matter, making it difficult to detect its sources. Similarly, some nuclear materials do not emit radiation to make them directly detectable. Typical explosive materials are characterized by their nitrogen (a bonding agent), oxygen (an oxidizer), hydrogen and carbon (fuel elements) content, but many innocuous materials have similar composition. Also, narcotics are organic materials with composition not too different from other organics. Many biological hazardous materials do not exhibit easily distinguishable characteristics. In addition, the presence of threat materials can be obscured by concealment within other harmless substances.  Moreover, threat materials do not generally have any particular geometric shape or pattern. Nonintrusive detection of contraband and threat materials also requires reliable, fast and deployable detection equipment. Therefore, the detection of threat materials challenges conventional nondestructive testing and imaging techniques, which exploit a particular physical property to distinguish one material from another. This presentation will explore the characteristics of CBRN materials that make them distinguishable from common substances; including density, chemical composition, volatility, crystal structure, heat conductivity, magnetic permeability, dielectric constant, nuclear spin, radioactivity and susceptibility to nuclear activation. The importance of detection orthogonality will be emphasized.  Existing detection techniques will be appraised, and methods recently developed for detecting indiscernible threat materials will be presented. The presentation will also outline remaining challenges and research and development opportunities.

Brief biography:
Esam M. A. Hussein is a professor in the Department of Mechanical Engineering, and Associate Dean of Engineering at the University of New Brunswick, Fredericton, Canada. After completing his undergraduate studies and a master's degree in nuclear engineering at Alexandria University, Egypt, he earned a PhD in nuclear engineering from McMaster University, Canada. Prior to joining the University of New Brunswick in November 1984, he was employed for four years as a Nuclear Design Engineer at Ontario Hydro.

He is leading a research program that focuses on the industrial and medical uses of nuclear and atomic radiation for non-destructive testing and imaging and for the detection of threat materials.  He has published numerous scientific papers and industrial reports, and is a holder of six patents, and the author of three books, with one more in preparation  Dr. Hussein is a recipient of the Canadian Nuclear Innovation Achievement Award in June 2003, and the Sylvia Fedoruk Award - 2000 of the College of Physicists in Medicine and the Canadian Organization of Medical Physics.