Laser-target interaction to initiate the secondary particles

I read the advanced example of Hadrontherapy ( but unable to use it to simulate a laser beam hiting on target to produce protons. Aslo, the optical-photon using G4EmStandard-opt4 didn’t help.

Would you please help me to simulate laser-target leading to particle production? I want to find the proton-soectrum from this process.
Thank you very much

Hi! I don’t think geant4 will help you with that. It was created for particle interaction with matter and cannot simulate laser interaction. For laser interaction I can recommend you to see PIC simulation methods.

Can you provide more details of the reactions involved? Maybe a link to relevant literature?

Geant4 simulates individual quanta: for a “laser beam,” the Geant4 particle would be a single photon (G4Gamma) with an energy of less than 1 eV. This isn’t going to produce secondary protons by any means other than maybe proton recoils in a pure hydrogen target.

For producing protons, I guess that you need a laser with an extremely high energy density, such that you have coherent multiphoton interactions. That’s not part of the standard Geant4 physics processes, but there’s no reason you couldn’t write your own process for this.

thank you very much,
I have found some papers using GEANT4 to simulate laser-plasma driven system:
A-MonteCarloapplicationbasedonGEANT4toolkittosimulate a laser–plasma electronbeamlineforradiobiologicalstudies.
B -Geant4 simulation of the ELIMED transport and dosimetry beam line for high-energy
laser-driven ion beam multidisciplinary applications.

It is very interesting to using GEANT4 in such simulations but dont know how.