Dosimetry of a dual-energy cargo inspection system using monte carlo simulation

Todays, X-ray imaging system for cargo and containers inspecting of country gates are highly regarded. The dual energy imaging system due to the use of two beams with different spectrums can extracts more information about the materials in cargo than the conventional X-ray imaging system. Since the X-ray beam is an ionizing radiation, three parameters should be taken into account including justifiably, optimization and dose limits. In this study to evaluate the exposure for materials inside cargo, staffs and for around of system, we simulated a typical system using Monte Carlo code. With using 750 mCi of 137Cs and 1 Ci of 60Co, exposure rates for the water phantom in the center of cargo were 10μSv/h and 20μSv/h for 137Cs and 60Co, respectively. Also, the exposure rate at a distance of 10 meter around the system without any additional protection lies almost in the appropriate value. The results of simulations show that with using the line scan system and a good designing for source shielding, the exposure at cargo inside and environment of it can be put in suitable values.