Utilizing experimental cross sections with NeutronHP physics


I’d like to use experimentally-derived cross sections is my simulation, particularly for chlorine isotope (n,p) and (n, alpha) reactions with E_n < 20 MeV. I’m using the QGSP_BERT_HP physics model. I’m using the ENDF-VIII library from GEANT 4 Libraries . I’m trying to use geant4 so I can compute corrections for scattering in my detector. I’m using 4.10.07 by the way.

I found this (Custom cross-section for hadronic processes) and based on the last comment attempted to modify the relevant cross sections in the G4NEUTRONHPDATA but the results did not match my cross sections, and instead matched the ENDF-VIII data. I do have the proper data set selected and referenced in my geant4.sh file.

I’m not sure if I’m going about this the correct way, and my searches haven’t turned up any other solutions. Is this something I need to modify in the code for my project? I’d like to avoid a custom physics model if possible and stick to the models built into geant.

Thank you for taking the time to read this! And thanks in advance for any potential directions or solutions you could point me towards!

I’ve got a solution for this now. I was referencing Hadronic Physics — Book For Toolkit Developers 11.0 documentation and it mentioned the G4VIsotope-Production class. I couldn’t find this searching through the code, other than a reference to a removal of a similar class in the version notes. Further testing showed that modifying anything in (or completely removing) the IsotopeProduction directory (G4NDL4.6/IsotopeProduction or ENDF-VIII.0/IsotopeProduction which is copied from G4NDL4.6) had no effect and did not cause any runtime errors. I found that instead the cross sections are located in G4NDL4.6/Inelastic or ENDF-VIII.0/Inelastic. I had passed over this directory originally because I thought it applied only to inelastic scattering.