I am currently working with Geant4 10.06.p03 and I am attempting to simulate a ~30 keV gamma interaction with a YAP scintillator (~1mm thickness). I am interested in observing the total number of generated scintillation photons.
In my current build (I think) I have low energy electromagnetic physics for atomic de-excitation turned on, through the use of “fluo”, “auger”, “augerCascade”, and “pixe” set to True in my physics lists script. I am also using the EMLivermore physics list as well.
Upon a run, I observed a bi-modal response (two peaks: one at 350 photons, which makes up about 90% of the total data, and another at around 790 photons) in a histogram of the total number of scintillation photons generated, when holding the position of interaction constant. If I perform the same simulation, instead using electrons, seeded at the point of interaction, with the same energy as that of the previously incoming gamma, I generate a histogram with a single peak, with a mean of 835 photons.
My current thought is that I am somehow not including some library/method needed to simulate the gamma-electron interaction properly. Please let me know if you think this is the case, and/or what I could do to correct this issue.
Thank you all for your time reading this. If you would like any other information to aid you in understanding my issue please let me know and I will gladly make it available.