USE OF NEARLY MONOCHROMATIC AND TUNABLE PHOTON SOURCES WITH NUCLEAR RESONANCE FLUORESCENCE IN NON-INTRUSIVE INSPECTION OF CONTAINERS FOR MATERIAL DETECTION AND IMAGING

• Main Authors: BERTOZZI, William, LEDOUX, Robert J
• Format: Patent
• Language: English; French; German
• Published: 01.02.2017
• Subjects: DETECTING MASSES OR OBJECTS; GEOPHYSICS; GRAVITATIONAL MEASUREMENTS; INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIRCHEMICAL OR PHYSICAL PROPERTIES; MEASURING; PHYSICS; TESTING

A method and apparatus for detecting a potential item of interest in a target sample, the method comprising: a) providing a source of photons (12) with an energy spectrum that overlaps a nuclear resonance in the item of interest, wherein the photons from the source are generated by at least one of: Compton scattering of photons by electrons; passage of electrons through a periodic lattice; a particle-induced reaction in a nucleus; and passage of bremsstrahlung radiation photons through at least one absorber constituting a graded filter comprising both high-Z and lower-Z materials; b) illuminating the target sample (20,22) with photons (34) from the source; c) providing at least one reference scatterer (28), the reference scatterer (28) comprising at least one nuclear species of interest; d) allowing photons transmitted through the target sample (20,22) to scatter from the at least one reference scatterer (28); e) providing at least one photon detector (42) to measure an intensity of photons scattered (48) from the at least one reference scatterer (28) in at least one energy channel; and f) identifying an item of interest detection event if the intensity of photons detected in at least one of the at least one energy channels of interest meets a predetermined item of interest detection criterion.