Evaluation of different X-ray tube concepts with the simulation package ROSI

The modelling of complex X-ray tube setups requires a reliable simulation code which should be easy to use. ROSI (ROentgen SImulation, http://www.pi4.physik.unierlangen.de/Giersch/ROSI) was developed for that purpose and represents an object-oriented open source Monte Carlo simulation code that is based on the C++ library LSCAT-Gismo. The library uses the well established EGS4 code and its low energy extension LSCAT. One design that was modelled is a thin anode transmission tube design composed of a thin tungsten layer. The other was a wedge design, composed as well of a thin tungsten layer covering a wedge shaped cut out in a graphite substrate. The transmission tube design has been studied extensively regarding the X-ray flux efficiency compared to conventional tube setups. Here different geometries, electron impact angles and material combinations were investigated. The wedge design is a continuation of the transmission concept, but with a different geometry. Here as well we have studied different wedge angles, layer thicknesses and tube voltages in order to maximize the X-ray flux per deposited energy. The wedge design shows a great advantage relative to the diminutive amount of backscattered electrons and hence has an increased efficiency.