Low energy electrons are not ionizing

Hi, I am looking at verbose tracking for root files with only one event thrown. We have been trying to implement the Livermore EM physics libraries. I am seeing a lot of low energy electrons (on the order of a few keV) that are bouncing around different geometries without losing any kinetic energy. I would expect these electrons to undergo ionization in these materials (usually G10), but they’re only undergoing the process “coupled transportation”.

I have tried going into the physics list processes and dropping the minimum energy threshold for the electron ionization process to 10eV. My hope was that the electrons were so low in energy that G4 ionization wasn’t affecting them. However, I’m still seeing lots of electrons moving through material without ionizing and without losing kinetic energy.

I read into coupled transportation, and I think that I can change the energy threshold for which loops will be killed. This seems a little complicated, and I’m not sure that it’s the right solution. I have also considered implementing some kind of step limiter, but that seems like it’s not really addressing the issue.

Has anyone else had a similar issue in which they see low energy electrons moving around physical geometries without losing energy? Sometimes these electrons can do this for tens of thousands of steps and take up a massive amount of CPU time.

Hi, which version of Geant4 are you using? could you please repeat the test for example G4EMPenelope physics constructor? I agree NOT to touch any parameter of the coupled transportation. What you observe should not happen.