ABSTRACT
The most important theoretical publications relevant to the interactions of electrons and photons in an X-ray target were published during the 1920s to 1980s. It is perhaps surprising, therefore, that X-ray spectra modeling remains an active field for research. The fact that it is still active can be attributed to several factors:
The problem of X-ray spectrum generation in a thick target is a coupled electron-photon transport problem and, hence, complicated to solve. The availability of increasingly powerful computers has enabled new calculations, mostly based on the use of Monte Carlo simulations.
Many of the theoretical results are derived using approximations and have regimes of validity that need to be considered in each application.
The sheer variety of X-ray system designs and working energy ranges means that a model that is adequate in one application may be quite useless in another.
Scientists working with X-ray beams want models that are simple and quick to use, and this requires ingenuity in distilling the essential physics from the complex theoretical framework.
