Non-ionizing energy loss example simulation

Hello all, is there an example to simulate non-ionizing energy loss (NIEL) in geant4 (in basic/extended)? I managed to find couple of topics on old Hypernews forum but they seem to be not viewable now. Thank you.

Look in TestEm7, and in particular at the G4ScreenedNuclearRecoil stuff. You will want to go through both the .hh and .cc file in detail to understand what’s going on, as there are multiple classes incorporated in there.

Thank you for your help. I will definitely check the example.


NIEL is computed in EMZ(Opt4) and EMY (Opt3) EM physics. This computation is valid for ions below 1 MeV/u. Unfortunately, we have not histogram or simple cout in our examples.

With Geant4 10.6 we provided a new method how to compute NIEL independently on particle energy: G4NIELCalculator. This is a helper class, which should be included in your stepping action. The example is in $G4INSTALL/example/extended/electromagnetic/TestEm1.


That’s very cool, Vladimir! Does 10.6 provide a mechanism to specify different NIEL model computations? We added that functionality privately in our CDMS code (which is still supporting back to 10.4), with two different models prewritten (Lewin-Smith and Lindhard-Robinson), along with adding additional models at compile time.

Thank you for your reply. So I can’t use testem7 example to do 10 MeV ~ 500 MeV proton NIEL simulation under geant4 10.6 version? (I am using 10.5 right now) Will I be able to measure it using the 10.6 version and testem1 example?