Killing a track in SteppingAction?

[shayan0373n]

In Geant4, you can delete a track in SteppingAction like this:

G4Track* track = step->GetTrack();
track->SetTrackStatus(fStopAndKill);

I've noticed that SetTrackStatus (and seemingly many other setter methods) are not available in Python bindings. Is this intentional? Do you have any suggestions on how to kill a track, for example, when the energy has dropped below a certain threshold?

[HaarigerHarald]

It's not intentional some things just weren't bound to python yet. Can you verify that they are available now with 54a420faf3dc378e1594d8988f3f8fc947231ac1 and work correctly?

[shayan0373n]

Thanks for the quick update. Unfortunately, I currently don't have the required build setup to test the changes. I will try over the weekend if it is left untested.

To test SetTrackStatus we can use examble B1 and change the UserSteppingAction method in B1SteppingAction class to:

def UserSteppingAction(self, aStep):
    if self.fScoringVolume == None:
        detectorConstruction = G4RunManager.GetRunManager().GetUserDetectorConstruction()
        self.fScoringVolume = detectorConstruction.fScoringVolume

    volume = aStep.GetPreStepPoint().GetTouchable().GetVolume().GetLogicalVolume()

    # check if we are in scoring volume
    if volume != self.fScoringVolume:
        return
    else:
        # collect energy deposited in this step
        edepStep = aStep.GetTotalEnergyDeposit()
        self.fEventAction.AddEdep(edepStep)
        # kill the track !TEST!
        track = aStep.GetTrack()
        track.SetTrackStatus(fStopAndKill)

Edit: The expected result should show a significantly lower (but not zero) deposited energy, since we are killing the particles as soon as they reach the scoring volume of the detector.

[HaarigerHarald]

With this modification both C++ and Python yield the same result.

 Cumulated dose per run, in scoring volume : 677.265 picoGy  rms = 18.1942 picoGy 

I'll close this for now.