G4InteractionLawPhysical Class Reference

#include <G4InteractionLawPhysical.hh>

Inheritance diagram for G4InteractionLawPhysical:

Public Member Functions
	G4InteractionLawPhysical (G4String name="exponentialLaw")
virtual	~G4InteractionLawPhysical ()
void	SetPhysicalCrossSection (G4double crossSection)
G4double	GetPhysicalCrossSection () const
virtual G4double	ComputeEffectiveCrossSectionAt (G4double length) const
virtual G4double	ComputeNonInteractionProbabilityAt (G4double length) const
virtual G4double	SampleInteractionLength ()
virtual G4double	UpdateInteractionLengthForStep (G4double truePathLength)
Public Member Functions inherited from G4VBiasingInteractionLaw
	G4VBiasingInteractionLaw (G4String name)
virtual	~G4VBiasingInteractionLaw ()
const G4String &	GetName () const
virtual G4bool	IsSingular () const
virtual G4bool	IsEffectiveCrossSectionInfinite () const
G4double	Sample ()
G4double	UpdateForStep (G4double truePathLength)
G4double	GetSampledInteractionLength () const

Additional Inherited Members

Detailed Description

Definition at line 45 of file G4InteractionLawPhysical.hh.

Constructor & Destructor Documentation

G4InteractionLawPhysical::G4InteractionLawPhysical

(

G4String

name = "exponentialLaw"

)

Definition at line 29 of file G4InteractionLawPhysical.cc.

  : G4VBiasingInteractionLaw(name),
    fCrossSection(0.0),
    fCrossSectionDefined(false),
    fNumberOfInteractionLength(-1.0)
{}

G4InteractionLawPhysical::~G4InteractionLawPhysical ( )

virtual

Definition at line 36 of file G4InteractionLawPhysical.cc.

{}

Member Function Documentation

G4double G4InteractionLawPhysical::ComputeEffectiveCrossSectionAt ( G4double  length ) const

virtual

Implements G4VBiasingInteractionLaw.

Definition at line 53 of file G4InteractionLawPhysical.cc.

References G4Exception(), and JustWarning.

Referenced by G4BiasingProcessInterface::PostStepDoIt().

{
  if (!fCrossSectionDefined) G4Exception("G4InteractionLawPhysical::ComputeEffectiveCrossSection(..)",
                     "BIAS.GEN.15",
                     JustWarning,
                     "Cross-section value requested, but has not been defined yet. Assumes 0 !");
  return fCrossSection;
}

G4double G4InteractionLawPhysical::ComputeNonInteractionProbabilityAt ( G4double  length ) const

virtual

Implements G4VBiasingInteractionLaw.

Definition at line 62 of file G4InteractionLawPhysical.cc.

References G4Exception(), and JustWarning.

Referenced by G4BiasingProcessInterface::AlongStepDoIt().

{
  if (!fCrossSectionDefined) G4Exception("G4InteractionLawPhysical::ComputeNonInteractionProbability(..)",
                     "BIAS.GEN.16",
                     JustWarning,
                     "Non interaction probabitlity value requested, but cross section has not been defined yet. Assumes it to be 0 !");
  // -- allows zero cross-section case, by convention:
  if ( fCrossSection == 0.0 ) return 1.0;
  else return std::exp(-fCrossSection*stepLength);
}

G4double G4InteractionLawPhysical::GetPhysicalCrossSection ( ) const

inline

Definition at line 53 of file G4InteractionLawPhysical.hh.

Referenced by G4BOptnChangeCrossSection::GetBiasedCrossSection().

{return fCrossSection;}

G4double G4InteractionLawPhysical::SampleInteractionLength ( )

virtual

Implements G4VBiasingInteractionLaw.

Definition at line 73 of file G4InteractionLawPhysical.cc.

References DBL_MAX, FatalException, G4Exception(), and G4UniformRand.

{
  if ( !fCrossSectionDefined || fCrossSection < 0.0 )  G4Exception("G4InteractionLawPhysical::Sample(..)",
                                   "BIAS.GEN.17",
                                   FatalException,
                                   "Trying to sample while cross-section is not defined or < 0 !");
  if ( fCrossSection == 0.0 ) return DBL_MAX;

  fNumberOfInteractionLength =  -std::log( G4UniformRand() );
  return fNumberOfInteractionLength/fCrossSection;
}

void G4InteractionLawPhysical::SetPhysicalCrossSection

(

G4double

crossSection

)

Definition at line 39 of file G4InteractionLawPhysical.cc.

References G4Exception(), and JustWarning.

Referenced by G4BiasingProcessInterface::PostStepGetPhysicalInteractionLength(), and G4BOptnChangeCrossSection::SetBiasedCrossSection().

{
  if (crossSection < 0.0)
    {
      G4Exception("G4InteractionLawPhysical::SetPhysicalCrossSection(..)",
          "BIAS.GEN.14",
          JustWarning,
          "Cross-section value passed is negative. It is set to zero !");
      crossSection = 0.0;
    }
  fCrossSectionDefined = true;
  fCrossSection        = crossSection;
}

G4double G4InteractionLawPhysical::UpdateInteractionLengthForStep ( G4double  truePathLength )

virtual

Reimplemented from G4VBiasingInteractionLaw.

Definition at line 86 of file G4InteractionLawPhysical.cc.

References G4endl, G4Exception(), G4VBiasingInteractionLaw::GetName(), and JustWarning.

{
  fNumberOfInteractionLength -= truePathLength*fCrossSection;
  if ( fNumberOfInteractionLength < 0 ) 
    {
      G4ExceptionDescription ed;
      ed << " Negative number of interaction length for `" << GetName() << "' " << fNumberOfInteractionLength << ", set it to zero !" << G4endl; 
      G4Exception("G4InteractionLawPhysical::UpdateInteractionLengthForStep(...)",
          "BIAS.GEN.13",
          JustWarning,
          ed);
      fNumberOfInteractionLength = 0.;
    }
  return  fNumberOfInteractionLength;
}

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The documentation for this class was generated from the following files:

• G4InteractionLawPhysical.hh
• G4InteractionLawPhysical.cc