Portable And Autonomous X-Ray Equipment For In-Situ Threat Materials Identification By Effective Atomic Number High-Accuracy Measurement

A novel portable and autonomous X-ray dual-energy Radioscopy equipment, developed for bomb squad interventions and NDT applications and capable of in-situ digital radiography imaging with measurement of the effective Atomic number of materials (Z(eff)), is presented. The system consists of a 2D dual-energy X-ray detector based on a rapidly translated linear array, a portable X-ray source and dedicated software running on a laptop or tablet PC. By measurement of the collected x-ray intensities at two different energy spectra, the system can directly compute the material Z(eff) value for various organic materials contained in the scanned object and then identify them from a database list. The entire system calibration has been obtained using explosive simulants with known Z(eff) values, the measurement error of Z(eff) being around +/- 3.5% with respect to the reference values. The excellent image resolution and the ability of the automated threat identification algorithm are presented for experiments with a briefcase and a hand-held baggage having various domestic objects and an explosive simulant inside.