The Differential X-Ray Absorption Model provides a qualitative exploration of how X-rays interact with varying material properties and how this difference can produce contrast in the x-ray image.  For a typical medical diagnostic, images are created when X-rays from a source penetrate an object and then expose a film. This simulation shows how different materials in the X-rays beam produce the contrast that generates the detail of the image.

The Differential X-Ray Absorption Model was created by Michael Gallis using the Easy Java Simulations (EJS) modeling tool. It is distributed as a ready-to-run (compiled) Java archive. You can examine and modify this compiled EJS model if you run the model (double click on the model's jar file), right-click within a plot, and select "Open Ejs Model" from the pop-up menu. You must, of course, have EJS installed on your computer. 

Please note that this resource requires at least version 1.6 of Java (JRE).