include/Geant4/G4ILawForceFreeFlight.hh

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0025 //
0026 // G4ILawForceFreeFlight
0027 //
0028 // Class Description:
0029 //
0030 // A G4VBiasingInteractionLaw representing the "interaction" law
0031 // for a force free flight, ie, a particle which does not interact.
0032 // It is a limit case for which the non-interaction probability over
0033 // a segment is always 1, and the effective cross-section always
0034 // zero. This singular behavior is signaled by the IsSingular()
0035 // method returning always true.
0036 //
0037 // Author: Marc Verderi, November 2013.
0038 // --------------------------------------------------------------------
0039 #ifndef G4ILawForceFreeFlight_hh
0040 #define G4ILawForceFreeFlight_hh 1
0041
0042 #include "G4VBiasingInteractionLaw.hh"
0043
0044 class G4ILawForceFreeFlight : public G4VBiasingInteractionLaw
0045 {
0046   public:
0047
0048     G4ILawForceFreeFlight(const G4String& name = "forceFreeFlightLaw");
0049     virtual ~G4ILawForceFreeFlight();
0050
0051     virtual G4double ComputeEffectiveCrossSectionAt(G4double length) const;
0052     virtual G4double ComputeNonInteractionProbabilityAt(G4double length) const;
0053
0054     // -- sample the distribution
0055     virtual  G4double SampleInteractionLength();
0056     // -- move by true path length, this position becomes the new initial point
0057     virtual G4double UpdateInteractionLengthForStep(G4double truePathLength);
0058     virtual G4bool IsSingular() const { return true; }
0059 };
0060
0061 #endif