include/Geant4/G4ILawForceFreeFlight.hh

0001 //
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0025 //
0026 //
0027 //
0028 // ---------------------------------------------------------------
0029 //
0030 // G4ILawForceFreeFlight
0031 //
0032 // Class Description:
0033 //     A G4VBiasingInteractionLaw representing the "interaction" law
0034 //  for a force free flight, ie, a particle which does not interact.
0035 //  It is a limit case for which the non-interaction probability over
0036 //  a segment is always 1, and the effective cross-section always
0037 //  zero.
0038 //     This singular behavior is signaled by the IsSingular()
0039 //  method returning always true.
0040 //
0041 // ---------------------------------------------------------------
0042 //   Initial version                         Nov. 2013 M. Verderi
0043 #ifndef G4ILawForceFreeFlight_hh
0044 #define G4ILawForceFreeFlight_hh 1
0045
0046 #include "G4VBiasingInteractionLaw.hh"
0047
0048 class G4ILawForceFreeFlight : public G4VBiasingInteractionLaw
0049 {
0050 public:
0051   G4ILawForceFreeFlight(G4String name = "forceFreeFlightLaw");
0052   virtual ~G4ILawForceFreeFlight();
0053
0054 public:
0055   virtual G4double     ComputeEffectiveCrossSectionAt(G4double               length) const;
0056   virtual G4double ComputeNonInteractionProbabilityAt(G4double               length) const;
0057   // -- sample the distribution
0058   virtual  G4double           SampleInteractionLength();
0059   // -- move by true path length, this position becomes the new initial point
0060   virtual G4double     UpdateInteractionLengthForStep(G4double       truePathLength);
0061   virtual G4bool IsSingular() const {return true;}
0062 };
0063
0064 #endif