The X-ray intensity as measured by detectors depends on all aspects of the imaging system ranging from the source spectrum to various scatter events during the photon transport. The proposed simulator models the entire X-ray detection process from photon generation to various scatter events to the eventual detection of transmitted/scattered photons. In particular, the simulator models the two important form factors--coherent (Rayleigh and small angle) and incoherent (Compton)--to better guide the design of security imaging systems towards cost-effective and efficient operation aimed at optimizing classification of objects in packed bags as threats or benign. Central to the simulator are the analytical models for various components of X-ray physics. All components of the X-ray imaging system are modeled and parameterized with user specified parameters such as the scanner geometry (source/detector/conveyor positions), source characteristics (spectral shape, kVp and beam intensity profile of the X-ray source), and detector spectral response. In addition, various apertures (e.g., coded aperture) and collimators may also be included anywhere in the optical path. For instance, the vane collimators at the detectors typically used in CT scanners will also be modeled by the simulator. Such parameterization allows individual users to emulate any X-ray based imaging system. In particular, the simulator, through appropriate parameterization will allow the modeling of any Computed Tomography (CT) based Explosive Detection System (EDS).
