Simulation of X-ray tubes for imaging applications

This work describes the simulation of X-ray tubes used in imaging applicati ons. The cross section for the electron impact ionisation of the K-shell fo r selected materials, and given by different sources, is analysed. An enhan ced version of the EGS4 code incorporating different models to deal with io nisation of the K-shell by electron impact is briefly described. The code i s then used to simulate photon spectra produced in X-ray tubes operating at energies below 100 keV. The results obtained for silver and molybdenum tar gets in transmission and reflection geometries, and for different tube volt ages, are then benchmarked against experimental data. The results show an o verall good agreement between simulated and experimental data. It is shown that the accuracy of the result depends on the model used to deal with the ionisation of the K-shell. When appropriate models are in use, simulated an d experimental spectra agree within 15% at the K-alpha peak.