Hello,
Say I have a perpendicular beam of neutrons striking an aluminum slab with a perfect crystal lattice. If the first neutron in the beam is energetic enough, it can scatter an Al atom away from its lattice site and the second neutron in the beam will “see” one less Al atom in its path (I’m considering a very ideal case for simplicity).
However, from my understanding, Geant4 doesn’t account for crystal structure or atom positions when using the Geant4 Material database, NIST compounds, atom mixtures, etc. (I found some relevant links stating this at https://geant4-forum.web.cern.ch/t/oxygen-as-a-molecule/2480 and https://geant4-forum.web.cern.ch/t/can-we-know-which-atom-the-deposited-energy-is-deposited-on/6888/5).
And so, my question is how does Geant4 account for atoms that have already been scattered away from the path of an incoming particle, if at all? Does Geant4 keep track of how much material each incident particle “sees” for every run despite how it doesn’t account for the crystal lattice? Or is the likelihood of scattering the same for each particle in the beam such that each particle sees the same material for every run?