Automatic Detection Of High-Z Material In Cargo

The United States Domestic Nuclear Detection Office (DNDO) Cargo Advanced Automatic Radiography System (CAARS) was an advanced technology demonstration to detect high-Z materials (Z, the atomic number, >= 72) in full sized cargo systems such as a 74 foot length tractor-trailer. The L-3 CAARS was one of two CAARS prototypes developed and tested under the program. The L-3 system utilized MeV range dual-energy photons to determine Z and a sophisticated image processing based detection algorithm to accomplish the detection. This paper describes the L-3 CAARS hardware, the physics approach to measuring Z, and presents some results from the system.