Validation of proton ionization cross section generators for Monte Carlo particle transport

Three software systems, ERCS08, ISICS 2011 and \v{S}mit's code, that implement theoretical calculations of inner shell ionization cross sections by proton impact, are validated with respect to experimental data. The accuracy of the cross sections they generate is quantitatively estimated and inter-compared through statistical methods. Updates and extensions of a cross section data library relevant to PIXE simulation with Geant4 are discussed.