Monte Carlo simulation tool with CAD interface

In radiography, irradiating the object and recording the transmitted radiation gives information about the inner structure of an object. The transmitted radiation consists of a primary and a scattered component. The Monte Carlo method allows the detailed description of the physics of radiation transport. On the other hand, it is necessary to handle complex object geometries to be able to simulate realistic inspection scenarios. Standard Monte Carlo programs like the Monte Carlo n-particle transport code MCNP (Los Alamos National Laboratories) use mainly simple geometrical forms such as parallelepipeds, ellipsoids, or planes to construct complex geometries in a proprietary way. Here a model is presented that combines the Monte Carlo method with the world of CAD. Components are described as closed triangulated surfaces using STL as exchange format, which is supported by all CAD systems. The opportunities of the presented Monte Carlo simulation tool are discussed in terms of various examples and compared to MCNP.