Society faces threats through the malicious use of chemical, biological, radiological, nuclear and/or explosive (CBRNE) materials. The detection of illicit trafficking or other criminal acts, as well as many security and safety applications, call for novel material analysis techniques and instruments. These detection systems should be non-destructive but still be able to detect and identify the threat objects, even from inside a shielding or masking enclosure. Active interrogation methods that use penetrative particle beams can reveal the presence of CBRNE materials.
"In prompt gamma neutron activation analysis (PGNAA), an unknown object is exposed to a high neutron flux and the outgoing prompt gamma radiation is measured with a high energy resolution gamma spectrometer. The emitted gamma rays are isotope-specific, so gamma neutron activation analysis can be used to detect the presence of nearly all elements," says Dr. Camille Bélanger-Champagne from the Helsinki Institute of Physics (HIP) at the University of Helsinki.