Monte Carlo simulation study of detector performance for X-ray baggage inspection system.

Silicon photodiodes coupled to scintillators are widely used for X-ray imaging applications involving radiography and tomography for security or medical applications. X-ray baggage inspection systems (XBIS) are used for detection of threat materials using dual energy radiography of objects. A basic understanding of these systems in terms of generation of scintillation photons, energy deposition in scintillators and charge generation in photodiodes is essential for the design of the systems and for optimizing the detector parameters to achieve desired imaging performance. In the present work, Monte Carlo simulations were carried out to analyze the performance of detectors starting from theoretical generation of X-ray spectrum. Using this spectrum detector performance for dual energy material discrimination was studied. X-ray images of objects for evaluating penetration capability were also obtained. The R-values were calculated for different materials for mono-energetic X-ray photons which were observed to be constant with the thickness of the material. However, these values were observed to be decreasing with the increase in the thickness of the material when actual 140 keV X-ray spectrum was used for the simulation. [ABSTRACT FROM AUTHOR]