An accelerator based cargo container inspection system for nuclear materials

The Idaho Accelerator Center at Idaho State University has been developing a cargo container imaging system to detect nuclear threats. Although cargo container inspection systems are currently in place using gamma-rays or X-rays, they were originally designed to detect contraband. Passive radiation monitoring systems have supplemented current imaging systems in an effort to detect nuclear threats but unfortunately suffer from false alarms due to naturally radioactive cargo. The detection of small, shielded radioactive elements is even more problematic. An electron accelerator based inspection system has been developed by the Idaho Accelerator Center and used to image a cargo container with 10 MeV bremsstrahlung photons. Neutrons and photons exiting the cargo container are detected. Preliminary imaging results from a full scale, cargo container assay prototype illustrate the feasibility of detecting nuclear threats.