I might have found a bug in Geant4. I reported it a month ago on Bugzilla, but finally it was left unsolved: https://bugzilla-geant4.kek.jp/show_bug.cgi?id=2557
Here are the details of my problem:
I try to produce positrons by injecting 5 GeV electrons to a 18 mm thick tungsten target, and I tried to record the energy deposition by using scoring mesh overlapped with the tungsten target.
The problem is that when I updated Geant4 from 10 to 11, the positron yield at the target exit gets higher. If I turn off the scoring mesh, the positron yield gets reduced (11.9 e+/e- redeuced to 11.7 e+/e-).
The difference between using and not using mesh is mainly at low positron energy range.
I think this should be a bug, since the mesh should not affect the simulation results.
Can someone help to double check?
Thanks very much in advance!