G4ElectroVDNuclearModel Class Reference

#include <G4ElectroVDNuclearModel.hh>

Inheritance diagram for G4ElectroVDNuclearModel:

Collaboration diagram for G4ElectroVDNuclearModel:

Public Member Functions
	G4ElectroVDNuclearModel ()
	~G4ElectroVDNuclearModel ()
G4HadFinalState *	ApplyYourself (const G4HadProjectile &aTrack, G4Nucleus &aTargetNucleus)
virtual void	ModelDescription (std::ostream &outFile) const
Public Member Functions inherited from G4HadronicInteraction
	G4HadronicInteraction (const G4String &modelName="HadronicModel")
virtual	~G4HadronicInteraction ()
virtual G4double	SampleInvariantT (const G4ParticleDefinition *p, G4double plab, G4int Z, G4int A)
virtual G4bool	IsApplicable (const G4HadProjectile &, G4Nucleus &)
G4double	GetMinEnergy () const
G4double	GetMinEnergy (const G4Material *aMaterial, const G4Element *anElement) const
void	SetMinEnergy (G4double anEnergy)
void	SetMinEnergy (G4double anEnergy, const G4Element *anElement)
void	SetMinEnergy (G4double anEnergy, const G4Material *aMaterial)
G4double	GetMaxEnergy () const
G4double	GetMaxEnergy (const G4Material *aMaterial, const G4Element *anElement) const
void	SetMaxEnergy (const G4double anEnergy)
void	SetMaxEnergy (G4double anEnergy, const G4Element *anElement)
void	SetMaxEnergy (G4double anEnergy, const G4Material *aMaterial)
const G4HadronicInteraction *	GetMyPointer () const
virtual G4int	GetVerboseLevel () const
virtual void	SetVerboseLevel (G4int value)
const G4String &	GetModelName () const
void	DeActivateFor (const G4Material *aMaterial)
void	ActivateFor (const G4Material *aMaterial)
void	DeActivateFor (const G4Element *anElement)
void	ActivateFor (const G4Element *anElement)
G4bool	IsBlocked (const G4Material *aMaterial) const
G4bool	IsBlocked (const G4Element *anElement) const
void	SetRecoilEnergyThreshold (G4double val)
G4double	GetRecoilEnergyThreshold () const
G4bool	operator== (const G4HadronicInteraction &right) const
G4bool	operator!= (const G4HadronicInteraction &right) const
virtual const std::pair< G4double, G4double >	GetFatalEnergyCheckLevels () const
virtual std::pair< G4double, G4double >	GetEnergyMomentumCheckLevels () const
void	SetEnergyMomentumCheckLevels (G4double relativeLevel, G4double absoluteLevel)
virtual void	BuildPhysicsTable (const G4ParticleDefinition &)

Private Member Functions
G4DynamicParticle *	CalculateEMVertex (const G4HadProjectile &aTrack, G4Nucleus &aTargetNucleus)
void	CalculateHadronicVertex (G4DynamicParticle *incident, G4Nucleus &target)

Private Attributes
G4double	leptonKE
G4double	photonEnergy
G4double	photonQ2
G4ElectroNuclearCrossSection *	electroXS
G4PhotoNuclearCrossSection *	gammaXS
G4TheoFSGenerator *	ftfp
G4LundStringFragmentation *	theFragmentation
G4ExcitedStringDecay *	theStringDecay
G4CascadeInterface *	bert

Additional Inherited Members
Protected Member Functions inherited from G4HadronicInteraction
void	SetModelName (const G4String &nam)
G4bool	IsBlocked () const
void	Block ()
Protected Attributes inherited from G4HadronicInteraction
G4HadFinalState	theParticleChange
G4int	verboseLevel
G4double	theMinEnergy
G4double	theMaxEnergy
G4bool	isBlocked

Detailed Description

Definition at line 50 of file G4ElectroVDNuclearModel.hh.

Constructor & Destructor Documentation

G4ElectroVDNuclearModel()

G4ElectroVDNuclearModel::G4ElectroVDNuclearModel

(

)

Definition at line 63 of file G4ElectroVDNuclearModel.cc.

 : G4HadronicInteraction("G4ElectroVDNuclearModel"),
   leptonKE(0.0), photonEnergy(0.0), photonQ2(0.0)
{
  SetMinEnergy(0.0);
  SetMaxEnergy(1*PeV);
  electroXS = 
    (G4ElectroNuclearCrossSection*)G4CrossSectionDataSetRegistry::Instance()->
    GetCrossSectionDataSet(G4ElectroNuclearCrossSection::Default_Name());
  gammaXS = 
    (G4PhotoNuclearCrossSection*)G4CrossSectionDataSetRegistry::Instance()->
    GetCrossSectionDataSet(G4PhotoNuclearCrossSection::Default_Name());

  // reuse existing pre-compound model
  G4GeneratorPrecompoundInterface* precoInterface 
    = new G4GeneratorPrecompoundInterface();
  G4HadronicInteraction* p =
    G4HadronicInteractionRegistry::Instance()->FindModel("PRECO");
  G4VPreCompoundModel* pre = static_cast<G4VPreCompoundModel*>(p);
  if(!pre) { pre = new G4PreCompoundModel(); }
  precoInterface->SetDeExcitation(pre);

  // string model
  ftfp = new G4TheoFSGenerator();
  ftfp->SetTransport(precoInterface);
  theFragmentation = new G4LundStringFragmentation();
  theStringDecay = new G4ExcitedStringDecay(theFragmentation);
  G4FTFModel* theStringModel = new G4FTFModel();
  theStringModel->SetFragmentationModel(theStringDecay);
  ftfp->SetHighEnergyGenerator(theStringModel);
    
  // Build Bertini model
  bert = new G4CascadeInterface();
}

Here is the call graph for this function:

~G4ElectroVDNuclearModel()

G4ElectroVDNuclearModel::~G4ElectroVDNuclearModel

(

)

Definition at line 98 of file G4ElectroVDNuclearModel.cc.

{
  delete theFragmentation;
  delete theStringDecay;
}

Member Function Documentation

ApplyYourself()

G4HadFinalState * G4ElectroVDNuclearModel::ApplyYourself ( const G4HadProjectile &  aTrack, G4Nucleus &  aTargetNucleus  )

virtual

Implements G4HadronicInteraction.

Definition at line 120 of file G4ElectroVDNuclearModel.cc.

{
    // Set up default particle change (just returns initial state)
    theParticleChange.Clear();
    theParticleChange.SetStatusChange(isAlive);
    leptonKE = aTrack.GetKineticEnergy();
    theParticleChange.SetEnergyChange(leptonKE);
    theParticleChange.SetMomentumChange(aTrack.Get4Momentum().vect().unit() );
    
    // Set up sanity checks for real photon production
    G4DynamicParticle lepton(aTrack.GetDefinition(), aTrack.Get4Momentum() );
    
    // Need to call GetElementCrossSection before calling GetEquivalentPhotonEnergy.
    G4Material* mat = 0;
    G4int targZ = targetNucleus.GetZ_asInt();
    electroXS->GetElementCrossSection(&lepton, targZ, mat);
    
    photonEnergy = electroXS->GetEquivalentPhotonEnergy();
    // Photon energy cannot exceed lepton energy
    if (photonEnergy < leptonKE) {
        photonQ2 = electroXS->GetEquivalentPhotonQ2(photonEnergy);
        G4double dM = G4Proton::Proton()->GetPDGMass() + G4Neutron::Neutron()->GetPDGMass();
        // Photon
        if (photonEnergy > photonQ2/dM) {
            // Produce recoil lepton and transferred photon
            G4DynamicParticle* transferredPhoton = CalculateEMVertex(aTrack, targetNucleus);
            // Interact gamma with nucleus
            if (transferredPhoton) CalculateHadronicVertex(transferredPhoton, targetNucleus);
        }
    }
    return &theParticleChange;
}

Here is the call graph for this function:

CalculateEMVertex()

G4DynamicParticle * G4ElectroVDNuclearModel::CalculateEMVertex ( const G4HadProjectile &  aTrack, G4Nucleus &  aTargetNucleus  )

private

Definition at line 156 of file G4ElectroVDNuclearModel.cc.

{
  G4DynamicParticle photon(G4Gamma::Gamma(), photonEnergy,
                           G4ThreeVector(0.,0.,1.) );

  // Get gamma cross section at Q**2 = 0 (real gamma)
  G4int targZ = targetNucleus.GetZ_asInt();
  G4Material* mat = 0;
  G4double sigNu =
    gammaXS->GetElementCrossSection(&photon, targZ, mat);

  // Change real gamma energy to equivalent energy and get cross section at that energy 
  G4double dM = G4Proton::Proton()->GetPDGMass() + G4Neutron::Neutron()->GetPDGMass();
  photon.SetKineticEnergy(photonEnergy - photonQ2/dM);      
  G4double sigK =
    gammaXS->GetElementCrossSection(&photon, targZ, mat);
  G4double rndFraction = electroXS->GetVirtualFactor(photonEnergy, photonQ2);

  // No gamma produced, return null ptr
  if (sigNu*G4UniformRand() > sigK*rndFraction) return 0;

  // Scatter the lepton
  G4double mProj = aTrack.GetDefinition()->GetPDGMass();
  G4double mProj2 = mProj*mProj;
  G4double iniE = leptonKE + mProj;               // Total energy of incident lepton
  G4double finE = iniE - photonEnergy;            // Total energy of scattered lepton
  theParticleChange.SetEnergyChange(finE-mProj);
  G4double iniP = std::sqrt(iniE*iniE-mProj2);    // Incident lepton momentum
  G4double finP = std::sqrt(finE*finE-mProj2);    // Scattered lepton momentum
  G4double cost = (iniE*finE - mProj2 - photonQ2/2.)/iniP/finP;  // cos(theta) from Q**2
  if (cost > 1.) cost= 1.;
  if (cost < -1.) cost=-1.;
  G4double sint = std::sqrt(1.-cost*cost);

  G4ThreeVector dir = aTrack.Get4Momentum().vect().unit();
  G4ThreeVector ortx = dir.orthogonal().unit();   // Ortho-normal to scattering plane
  G4ThreeVector orty = dir.cross(ortx);           // Third unit vector
  G4double phi = twopi*G4UniformRand();
  G4double sinx = sint*std::sin(phi);
  G4double siny = sint*std::cos(phi);
  G4ThreeVector findir = cost*dir+sinx*ortx+siny*orty;
  theParticleChange.SetMomentumChange(findir);    // change lepton direction

  // Create a gamma with momentum equal to momentum transfer
  G4ThreeVector photonMomentum = iniP*dir - finP*findir;
  G4DynamicParticle* gamma = new G4DynamicParticle(G4Gamma::Gamma(),
                                                   photonEnergy, photonMomentum);
  return gamma;
}

Here is the call graph for this function:

Here is the caller graph for this function:

CalculateHadronicVertex()

void G4ElectroVDNuclearModel::CalculateHadronicVertex ( G4DynamicParticle *  incident, G4Nucleus &  target  )

private

Definition at line 209 of file G4ElectroVDNuclearModel.cc.

{
  G4HadFinalState* hfs = 0;
  G4double gammaE = incident->GetTotalEnergy();

  if (gammaE < 10*GeV) {
    G4HadProjectile projectile(*incident);
    hfs = bert->ApplyYourself(projectile, target);
  } else {
    // At high energies convert incident gamma to a pion
    G4double piMass = G4PionZero::PionZero()->GetPDGMass();
    G4double piMom = std::sqrt(gammaE*gammaE - piMass*piMass);
    G4ThreeVector piMomentum(incident->GetMomentumDirection() );
    piMomentum *= piMom;
    G4DynamicParticle theHadron(G4PionZero::PionZero(), piMomentum);
    G4HadProjectile projectile(theHadron);
    hfs = ftfp->ApplyYourself(projectile, target);
  }

  delete incident;

  // Copy secondaries from sub-model to model
  theParticleChange.AddSecondaries(hfs);
}

Here is the call graph for this function:

Here is the caller graph for this function:

ModelDescription()

void G4ElectroVDNuclearModel::ModelDescription ( std::ostream &  outFile ) const

virtual

Reimplemented from G4HadronicInteraction.

Definition at line 104 of file G4ElectroVDNuclearModel.cc.

{
  outFile << "G4ElectroVDNuclearModel handles the inelastic scattering\n"
          << "of e- and e+ from nuclei using the equivalent photon\n"
          << "approximation in which the incoming lepton generates a\n"
          << "virtual photon at the electromagnetic vertex, and the\n"
          << "virtual photon is converted to a real photon.  At low\n"
          << "energies, the photon interacts directly with the nucleus\n"
          << "using the Bertini cascade.  At high energies the photon\n"
          << "is converted to a pi0 which interacts using the FTFP\n"
          << "model.  The electro- and gamma-nuclear cross sections of\n"
          << "M. Kossov are used to generate the virtual photon spectrum\n";
}

Member Data Documentation

bert

G4CascadeInterface* G4ElectroVDNuclearModel::bert

private

Definition at line 80 of file G4ElectroVDNuclearModel.hh.

electroXS

G4ElectroNuclearCrossSection* G4ElectroVDNuclearModel::electroXS

private

Definition at line 74 of file G4ElectroVDNuclearModel.hh.

ftfp

G4TheoFSGenerator* G4ElectroVDNuclearModel::ftfp

private

Definition at line 77 of file G4ElectroVDNuclearModel.hh.

gammaXS

G4PhotoNuclearCrossSection* G4ElectroVDNuclearModel::gammaXS

private

Definition at line 75 of file G4ElectroVDNuclearModel.hh.

leptonKE

G4double G4ElectroVDNuclearModel::leptonKE

private

Definition at line 70 of file G4ElectroVDNuclearModel.hh.

photonEnergy

G4double G4ElectroVDNuclearModel::photonEnergy

private

Definition at line 71 of file G4ElectroVDNuclearModel.hh.

photonQ2

G4double G4ElectroVDNuclearModel::photonQ2

private

Definition at line 72 of file G4ElectroVDNuclearModel.hh.

theFragmentation

G4LundStringFragmentation* G4ElectroVDNuclearModel::theFragmentation

private

Definition at line 78 of file G4ElectroVDNuclearModel.hh.

theStringDecay

G4ExcitedStringDecay* G4ElectroVDNuclearModel::theStringDecay

private

Definition at line 79 of file G4ElectroVDNuclearModel.hh.

---

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

• G4ElectroVDNuclearModel.hh
• G4ElectroVDNuclearModel.cc