Part of the XRTG4 extensions to the Geant4 toolkit is released under the terms of the GNU General Public License version 2.
It can be downloaded from our Github repository: https://github.com/cosine-eu/xrtg4-geant4-extension
Acknowledgement
We would appreciate it if you could acknowledge the use of our extension in any publication presenting results obtained with our extension. For instance:
Some of the ray-tracing results shown in this paper were obtained with the XRTG4 X-ray tracing extension to the Geant4 toolkit developed by cosine measurement systems (The Netherlands).