Is there an example of bremsstrahlung that occurs in X-ray lamps in program examples?
Could you please point to a paper to read to understand what you would like to do?
If you intend to model a X-ray tube, I suggest to start to look into the extended example Gamma Therapy. It generates an electron beam of 50 MeV, producing bremsstrahlung in a target. Then you can change the energy of the incident beam and the geometry.