Created attachment 355 [details] Macro, Random Seed and revised G4IonCoulombScatteringModel I ran an application where I replaced the standard EM Physics with CoulombScattering (using G4EmStandardPhysicsSS.hh). Doing so, some of my calculations failed after a particle has been created with indefinitely increasing energy during coulomb scattering. First I suspected my code (a class for a different hadronic interaction for alpha particles) to be the cause. However, tracking it down I found that I could reproduce the problem with a fresh build TestEm1 example. I have attached a .mac file and the Random Seed for the particular event (compiled with 4.10.1 p02 with QT, OpenGl and GDML). I looked into it further and found that this was caused by a track created for a DynamicParticle (in this case O16) with a dynamic mass set to a value different from the rest mass of 016. While I didn't understand the concept of the dynamic mass, I put a few line in G4IonCoulombScatteringModel.cc (version also attached). I think somehow the scattering logic fails to adhere to conservation of the total 4-momentum. I'm happy to supply more information if needed.
Hello Moritz, Thanks for reporting the problem The problem report #1763 address the same thing and fix has been introduced in the code. Unfortunately, this fix was not included into Geant4 10.1p02. Would it be possible if you try out 10.2beta? VI
Hello Moritz, next problem was identified in making 4-vector of the recoil. Now it is fixed and the fix will be available in the next public release, December,4. It may be also concidered for the new patch to 10.1. VI
