Studies of x-ray energy absorption and quantum noise properties of x-ray screens by use of Monte Carlo simulation.

The imaging properties of the phosphor layer in fluorescent screens or image intensifiers are related to its x-ray absorption characteristics. In this study, we applied Monte Carlo methods for the simulation of x-ray photon diffusion in a phosphor layer. The K-reabsorption factor, absorbed x-ray energy, quantum absorption efficiency, statistical factor, and noise-equivalent absorption were determined as a function of the incident energy and angle of the x rays for eight commonly used phosphor layers. These basic physical quantities will be useful for the prediction of the information transfer properties of a phosphor layer.