|Message: get Mean free path||Not Logged In (login)|
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My setup is a modification of example B2, where I replaced geometry by thin Silicon layer (250 Ám) and configured the Particle Gun to shoot single Pi+ per event perpendicular to the layer.
Now I need to get the value of Mean free path calculated by Geant for my material. I'm only interested in hadronic inelastic interactions.
here http://hypernews.slac.stanford.edu/HyperNews/geant4/get/fastsim/72/1.html I found the way to do it: "You can get the mean free path of a process calling its "G4double GetCurrentInteractionLength() const (method from G4VProcess)". If "-1" is returned, the process is not a true physical one (eg: transportation)."
So, now I get this value by aStep->GetTrack()->GetCreatorProcess()->GetCurrentInteractionLength() for the last step in the Volume for secondaries born by the process type fHadronic.
And values which I get are different (sometimes even by 2 orders!) and also I get "-1" value often.
As I see it, I should get (almost) same values, because I have only one homogeneous material and the shooting direction is always perpendicular and I should never get "-1", because I call this function only if aStep->GetTrack()->GetCreatorProcess()->GetProcessType()==4 (type fHadronic) i.e. this is a physical process.
Could you please tell me what I'm doing wrong? Or maybe explain me if these values are what they should be, but my expectations are wrong.
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