The primary detection technique for nuclear weapons, nuclear and other radioactive materials is passive gamma-ray and neutron detection using large area, high efficiency detectors which permit threat levels of radioactivity to be detected at practical scanning speeds (up to 30 km/hr is required in some cases to avoid impacting cargo throughput). If the radioactive source is heavily shielded by dense, high-Z material the passive detection technique may fail to detect the source. In this case, a complementary technique, such as x-ray or gamma-ray radiography can aid by detecting the dense material. Imaging willalso help verify that the cargo container contents are consistent with the manifest; thus, helping to resolve “nuisance alarms” from naturally radioactive material commonly found in cargo (for example, ceramic tiles, porcelain toilet bowls, kitty litter, etc.)
The primary Radiation Portal Monitors (RPM) typically are unable to determine the specific radionuclide(s) responsible for initiating an alarm. Thus, containers triggering an RPM alarm require secondary inspection. A handheld isotope identification system can perform a gamma-ray spectroscopic analysis near the suspect region of the container and determine the specific isotope causing the alarm. This measurement is essential for identifying “nuisance” alarms and allowing expeditious disposition of cargo in secondary
inspection. A material-specific non-intrusive technique such as fast and thermal neutron elemental analysis can aid in verifying the presence of WMD materials such as explosives, chemical agents, and nuclear materials (such as highly-enriched uranium) which cannot usually be detected passively but can be detected using neutrons to induce fission in the U-235.When processing hundreds of containers and trucks per day at a sea or land border port with multiple traffic lanes, it is essential to automate the positive identification of the container and truck. For instance, this will ensure that the alarming truck or container is properly directed to secondary. Fortunately, technologies for (automatic license plate readers) and cargo containers identification (video OCR systems) have been developed for logistics purposes and can be readily adapted for security applications.
The primary Radiation Portal Monitors (RPM) typically are unable to determine the specific radionuclide(s) responsible for initiating an alarm. Thus, containers triggering an RPM alarm require secondary inspection. A handheld isotope identification system can perform a gamma-ray spectroscopic analysis near the suspect region of the container and determine the specific isotope causing the alarm. This measurement is essential for identifying “nuisance” alarms and allowing expeditious disposition of cargo in secondary
inspection. A material-specific non-intrusive technique such as fast and thermal neutron elemental analysis can aid in verifying the presence of WMD materials such as explosives, chemical agents, and nuclear materials (such as highly-enriched uranium) which cannot usually be detected passively but can be detected using neutrons to induce fission in the U-235.When processing hundreds of containers and trucks per day at a sea or land border port with multiple traffic lanes, it is essential to automate the positive identification of the container and truck. For instance, this will ensure that the alarming truck or container is properly directed to secondary. Fortunately, technologies for (automatic license plate readers) and cargo containers identification (video OCR systems) have been developed for logistics purposes and can be readily adapted for security applications.
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