Weird problem with pre/post step energies of e-/e+


I’m noticing a weird bug in the values returned for preStepPoint kinetic energies and postStepPoint kinetic energies for e- and e+ compared to p and gamma. If I set a KE for the particle at generation, that energy should theoretically be both the pre and post KE (I am not doing anything to the particle itself, just recording it). This is true for protons and gamma particles for all energies. For some reason, however, when the provided energy is 1 keV or lower for e- or e+, the pre KE is the input (supposed to happen) while the KE just drops to 0 (not supposed to happen).

I have no idea why this would be happening, and I can only think that it can be a bug in the Geant4 installation. If so, how can I get around it? Please note that I am using the built-in Python environment for my simulations.

Thank you in advance for all of your help.



energy conservation in Geant4 is checked in many tests daily. Results should not depend on installation. Note, that when a particle is stopped due to energy loss or interaction, post step energy is set to zero. I would advice studying Geant4 examples. You not need changing anything, use examples to understand Geant4 tracking.



Thank you for the response; that clears up a number of issues I’ve had so far.