Nondestructive inspection using Compton scatter tomography

A method for non-invasively generating tomographic images of electron density in materials using Compton scattered gamma rays is investigated. Electron density is an indicator of density or composition changes in a material. In Compton scatter tomography, the energy distribution of monoenergetic gamma rays is measured after scattering from a material target. Measuring a scattered gamma ray's energy localizes the scattering position to a definable region of the sample. We develop an analytic computational model to study the image quality of a realistic system. In particular, the deleterious effects of finite source and detector size, Compton broadening, and Poisson noise are investigated. A backprojection algorithm is presented to demonstrate the impact of these effects on image reconstruction and contrast recovery. Detection of corrosion in low-Z materials is an application of interest, and is used to study the Compton scatter tomography technique.