Is it possible to use different physics lists in different volumes/materials in the same simulation?
I am interested in the production of radionuclids in air and so far QGSP_BIC_AllHP works best for this.
I am also interested in neutron production in light elements by stripping reaction and so far FTFP_INCLXX works best for this one.
Now i want to simulate a beam, which first passes through air (QGSP_BIC_AllHP should be used here) and then hits a target and produces neutrons (FTFP_INCLXX should be used here)
It is possible to have different EM physics models combinations in Geant4 Regions, however, I think this is not possible to do with the hadronic physics. What I would do is the following: run simulation study 1 with the beam traversing air. Then you store in a phase space file the particles reaching the target, with their energy, position and direction. You have to accumulate a very high statistics. Then you have simulation 2, where the particles of the phase space file are your primary radiation field and you track them in the target.