Comparison of recent experimental data with Monte Carlo tools such as RoSi, Geant4 and Penelope

The modeling of complex X-ray tube setups or photon detectors in the lower energy range of a few tens of keV requires a reliable simulation code which is also easy to use. ROSI (ROentgen SImulation, http://www.pi4.physik.uni-erlangen.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. We have worked thoroughly on validating the simulation results by comparing them to recently acquired experimental data and also cross checking with other established Monte Carlo tools such as Penelope and Geant4. Experimental setups that were used for validation were amongst others a setup for measuring the X-ray dose emitted by a thin tungsten target. This experiment was very valuable since the data was used to find the reason for the discrepancies between the different simulation tools in simulating the angular dose distribution. Two other experiments; one being the measurement of the backscattering coefficient for electrons and the other being the measurement of the angular distribution of the radiant power for various targets. The results of all three experiments served us as a good foundation for a thorough evaluation of our Monte Carlo tool.