Introduction to gamma-ray transmission tomography

Abstract

Conventional gamma ray computed tomography methods measure the attenuation of an incident beam that travels in a straight path through an object. The incident beam is partially absorbed and scattered in the object of interest, with the remaining transmitted radiation traveling in a straight line to the detector. This is the principle of gamma -ray transmission tomography. The amount of attenuation is related to the atomic number of the phases distributed in the object, as well as their density distributions. As with radiography, access to both side s of the structure is required. Any changes in the transmitted intensity to the adjacent detector will reflect the change s of the mass per unit area of the material.