Image formation in a gamma ray Compton Backscattering device

The Compton Camera is a backscattering device that allows us to obtain images of hidden objects. The device includes a 22Na source placed in a conical lead shielding and two geometrically opposing CsI detectors, one position sensitive detector in charge of building the image and a backscattering detector in charge of triggering the recollection of data. In order to study the image formation in the device we developed a theoretical approximation to evaluate the backscattered intensity as a function of depth. We have performed backscattering experiments to analyze the number of single and multiple backscattered photons as a function of thickness and to compare the experimental results with the theoretical model. The results of this comparison show that Multiple Compton events have a detrimental effect on the quality of the image and the Single Compton events build the image. We have evaluated the differences in backscattered intensity between two different materials to study the contrast in the image obtained