#include <G4LivermorePolarizedComptonModel.hh>

Inheritance diagram for G4LivermorePolarizedComptonModel:

Public Member Functions
	G4LivermorePolarizedComptonModel (const G4ParticleDefinition *p=nullptr, const G4String &nam="LivermorePolarizedCompton")

virtual	~G4LivermorePolarizedComptonModel ()

void	Initialise (const G4ParticleDefinition *, const G4DataVector &) override

void	InitialiseLocal (const G4ParticleDefinition , G4VEmModel masterModel) override

void	InitialiseForElement (const G4ParticleDefinition *, G4int Z) override

G4double	ComputeCrossSectionPerAtom (const G4ParticleDefinition *, G4double kinEnergy, G4double Z, G4double A=0, G4double cut=0, G4double emax=DBL_MAX) override

void	SampleSecondaries (std::vector< G4DynamicParticle * > , const G4MaterialCutsCouple , const G4DynamicParticle *, G4double tmin, G4double maxEnergy) override

G4LivermorePolarizedComptonModel &	operator= (const G4LivermorePolarizedComptonModel &right)=delete

	G4LivermorePolarizedComptonModel (const G4LivermorePolarizedComptonModel &)=delete

Public Member Functions inherited from G4VEmModel
	G4VEmModel (const G4String &nam)

virtual	~G4VEmModel ()

virtual void	InitialiseForMaterial (const G4ParticleDefinition , const G4Material )

virtual G4double	ComputeDEDXPerVolume (const G4Material , const G4ParticleDefinition , G4double kineticEnergy, G4double cutEnergy=DBL_MAX)

virtual G4double	CrossSectionPerVolume (const G4Material , const G4ParticleDefinition , G4double kineticEnergy, G4double cutEnergy=0.0, G4double maxEnergy=DBL_MAX)

virtual G4double	GetPartialCrossSection (const G4Material , G4int level, const G4ParticleDefinition , G4double kineticEnergy)

virtual G4double	ComputeCrossSectionPerShell (const G4ParticleDefinition *, G4int Z, G4int shellIdx, G4double kinEnergy, G4double cutEnergy=0.0, G4double maxEnergy=DBL_MAX)

virtual G4double	ChargeSquareRatio (const G4Track &)

virtual G4double	GetChargeSquareRatio (const G4ParticleDefinition , const G4Material , G4double kineticEnergy)

virtual G4double	GetParticleCharge (const G4ParticleDefinition , const G4Material , G4double kineticEnergy)

virtual void	StartTracking (G4Track *)

virtual void	CorrectionsAlongStep (const G4MaterialCutsCouple , const G4DynamicParticle , const G4double &length, G4double &eloss)

virtual G4double	Value (const G4MaterialCutsCouple , const G4ParticleDefinition , G4double kineticEnergy)

virtual G4double	MinPrimaryEnergy (const G4Material , const G4ParticleDefinition , G4double cut=0.0)

virtual G4double	MinEnergyCut (const G4ParticleDefinition , const G4MaterialCutsCouple )

virtual void	SetupForMaterial (const G4ParticleDefinition , const G4Material , G4double kineticEnergy)

virtual void	DefineForRegion (const G4Region *)

virtual void	FillNumberOfSecondaries (G4int &numberOfTriplets, G4int &numberOfRecoil)

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

void	InitialiseElementSelectors (const G4ParticleDefinition *, const G4DataVector &)

std::vector< G4EmElementSelector * > *	GetElementSelectors ()

void	SetElementSelectors (std::vector< G4EmElementSelector * > *)

G4double	ComputeDEDX (const G4MaterialCutsCouple , const G4ParticleDefinition , G4double kineticEnergy, G4double cutEnergy=DBL_MAX)

G4double	CrossSection (const G4MaterialCutsCouple , const G4ParticleDefinition , G4double kineticEnergy, G4double cutEnergy=0.0, G4double maxEnergy=DBL_MAX)

G4double	ComputeMeanFreePath (const G4ParticleDefinition , G4double kineticEnergy, const G4Material , G4double cutEnergy=0.0, G4double maxEnergy=DBL_MAX)

G4double	ComputeCrossSectionPerAtom (const G4ParticleDefinition , const G4Element , G4double kinEnergy, G4double cutEnergy=0.0, G4double maxEnergy=DBL_MAX)

const G4Element *	SelectRandomAtom (const G4MaterialCutsCouple , const G4ParticleDefinition , G4double kineticEnergy, G4double cutEnergy=0.0, G4double maxEnergy=DBL_MAX)

const G4Element *	SelectTargetAtom (const G4MaterialCutsCouple , const G4ParticleDefinition , G4double kineticEnergy, G4double logKineticEnergy, G4double cutEnergy=0.0, G4double maxEnergy=DBL_MAX)

const G4Element *	SelectRandomAtom (const G4Material , const G4ParticleDefinition , G4double kineticEnergy, G4double cutEnergy=0.0, G4double maxEnergy=DBL_MAX)

const G4Element *	GetCurrentElement (const G4Material *mat=nullptr) const

G4int	SelectRandomAtomNumber (const G4Material *) const

const G4Isotope *	GetCurrentIsotope (const G4Element *elm=nullptr) const

G4int	SelectIsotopeNumber (const G4Element *) const

void	SetParticleChange (G4VParticleChange , G4VEmFluctuationModel f=nullptr)

void	SetCrossSectionTable (G4PhysicsTable *, G4bool isLocal)

G4ElementData *	GetElementData ()

G4PhysicsTable *	GetCrossSectionTable ()

G4VEmFluctuationModel *	GetModelOfFluctuations ()

G4VEmAngularDistribution *	GetAngularDistribution ()

G4VEmModel *	GetTripletModel ()

void	SetTripletModel (G4VEmModel *)

void	SetAngularDistribution (G4VEmAngularDistribution *)

G4double	HighEnergyLimit () const

G4double	LowEnergyLimit () const

G4double	HighEnergyActivationLimit () const

G4double	LowEnergyActivationLimit () const

G4double	PolarAngleLimit () const

G4double	SecondaryThreshold () const

G4bool	DeexcitationFlag () const

G4bool	ForceBuildTableFlag () const

G4bool	UseAngularGeneratorFlag () const

void	SetAngularGeneratorFlag (G4bool)

void	SetHighEnergyLimit (G4double)

void	SetLowEnergyLimit (G4double)

void	SetActivationHighEnergyLimit (G4double)

void	SetActivationLowEnergyLimit (G4double)

G4bool	IsActive (G4double kinEnergy) const

void	SetPolarAngleLimit (G4double)

void	SetSecondaryThreshold (G4double)

void	SetDeexcitationFlag (G4bool val)

void	SetForceBuildTable (G4bool val)

void	SetFluctuationFlag (G4bool val)

void	SetMasterThread (G4bool val)

G4bool	IsMaster () const

void	SetUseBaseMaterials (G4bool val)

G4bool	UseBaseMaterials () const

G4double	MaxSecondaryKinEnergy (const G4DynamicParticle *dynParticle)

const G4String &	GetName () const

void	SetCurrentCouple (const G4MaterialCutsCouple *)

G4bool	IsLocked () const

void	SetLocked (G4bool)

void	SetLPMFlag (G4bool)

G4VEmModel &	operator= (const G4VEmModel &right)=delete

	G4VEmModel (const G4VEmModel &)=delete

Additional Inherited Members
Protected Member Functions inherited from G4VEmModel
G4ParticleChangeForLoss *	GetParticleChangeForLoss ()

G4ParticleChangeForGamma *	GetParticleChangeForGamma ()

virtual G4double	MaxSecondaryEnergy (const G4ParticleDefinition *, G4double kineticEnergy)

const G4MaterialCutsCouple *	CurrentCouple () const

void	SetCurrentElement (const G4Element *)

Protected Attributes inherited from G4VEmModel
G4ElementData *	fElementData = nullptr

G4VParticleChange *	pParticleChange = nullptr

G4PhysicsTable *	xSectionTable = nullptr

const G4Material *	pBaseMaterial = nullptr

const std::vector< G4double > *	theDensityFactor = nullptr

const std::vector< G4int > *	theDensityIdx = nullptr

G4double	inveplus

G4double	pFactor = 1.0

std::size_t	currentCoupleIndex = 0

std::size_t	basedCoupleIndex = 0

G4bool	lossFlucFlag = true

Detailed Description

Definition at line 44 of file G4LivermorePolarizedComptonModel.hh.

Constructor & Destructor Documentation

◆ G4LivermorePolarizedComptonModel() [1/2]

G4LivermorePolarizedComptonModel::G4LivermorePolarizedComptonModel	(	const G4ParticleDefinition *	p = nullptr,
		const G4String &	nam = "LivermorePolarizedCompton" )

explicit

Definition at line 84 of file G4LivermorePolarizedComptonModel.cc.

  :G4VEmModel(nam),isInitialised(false)
{ 
  verboseLevel= 1;
  // Verbosity scale:
  // 0 = nothing 
  // 1 = warning for energy non-conservation 
  // 2 = details of energy budget
  // 3 = calculation of cross sections, file openings, sampling of atoms
  // 4 = entering in methods
 
  if( verboseLevel>1 )  
    G4cout << "Livermore Polarized Compton is constructed " << G4endl;
        
  //Mark this model as "applicable" for atomic deexcitation
  SetDeexcitationFlag(true);
  
  fParticleChange = nullptr;
  fAtomDeexcitation = nullptr;
  fEntanglementModelID = G4PhysicsModelCatalog::GetModelID("model_GammaGammaEntanglement");
}

◆ ~G4LivermorePolarizedComptonModel()

G4LivermorePolarizedComptonModel::~G4LivermorePolarizedComptonModel ( )

virtual

Definition at line 108 of file G4LivermorePolarizedComptonModel.cc.

{  
  if(IsMaster()) {
    delete shellData;
    shellData = nullptr;
    delete profileData;
    profileData = nullptr;
    delete scatterFunctionData;
    scatterFunctionData = nullptr;
    for(G4int i=0; i<maxZ; ++i) {
      if(data[i]) { 
    delete data[i];
    data[i] = nullptr;
      }
    }
  }
}

◆ G4LivermorePolarizedComptonModel() [2/2]

G4LivermorePolarizedComptonModel::G4LivermorePolarizedComptonModel ( const G4LivermorePolarizedComptonModel & )

delete

Member Function Documentation

◆ ComputeCrossSectionPerAtom()

G4double G4LivermorePolarizedComptonModel::ComputeCrossSectionPerAtom	(	const G4ParticleDefinition *	,
		G4double	kinEnergy,
		G4double	Z,
		G4double	A = 0,
		G4double	cut = 0,
		G4double	emax = DBL_MAX )

overridevirtual

Reimplemented from G4VEmModel.

Definition at line 258 of file G4LivermorePolarizedComptonModel.cc.

{
  if (verboseLevel > 3)
    G4cout << "Calling ComputeCrossSectionPerAtom() of G4LivermorePolarizedComptonModel" << G4endl;
 
  G4double cs = 0.0; 
  
  if (GammaEnergy < LowEnergyLimit()) 
    return 0.0;
 
  G4int intZ = G4lrint(Z);
  if(intZ < 1 || intZ > maxZ) { return cs; } 
  
  G4PhysicsFreeVector* pv = data[intZ];
  
  // if element was not initialised
  // do initialisation safely for MT mode
  if(!pv) 
    {
      InitialiseForElement(0, intZ);
      pv = data[intZ];
      if(!pv) { return cs; }
    }
  
  G4int n = G4int(pv->GetVectorLength() - 1);   
  G4double e1 = pv->Energy(0);
  G4double e2 = pv->Energy(n);
  
  if(GammaEnergy <= e1)      { cs = GammaEnergy/(e1*e1)*pv->Value(e1); }
  else if(GammaEnergy <= e2) { cs = pv->Value(GammaEnergy)/GammaEnergy; }
  else if(GammaEnergy > e2)  { cs = pv->Value(e2)/GammaEnergy; }
  
  return cs;
 
}

◆ Initialise()

void G4LivermorePolarizedComptonModel::Initialise	(	const G4ParticleDefinition *	particle,
		const G4DataVector &	cuts )

overridevirtual

Implements G4VEmModel.

Definition at line 128 of file G4LivermorePolarizedComptonModel.cc.

{
  if (verboseLevel > 1)
    G4cout << "Calling G4LivermorePolarizedComptonModel::Initialise()" << G4endl;
 
  // Initialise element selector 
  if(IsMaster()) {
    // Access to elements 
    const char* path = G4FindDataDir("G4LEDATA");
 
    G4ProductionCutsTable* theCoupleTable = 
      G4ProductionCutsTable::GetProductionCutsTable();
 
    G4int numOfCouples = (G4int)theCoupleTable->GetTableSize();
    
    for(G4int i=0; i<numOfCouples; ++i) {
      const G4Material* material = 
        theCoupleTable->GetMaterialCutsCouple(i)->GetMaterial();
      const G4ElementVector* theElementVector = material->GetElementVector();
      std::size_t nelm = material->GetNumberOfElements();
      
      for (std::size_t j=0; j<nelm; ++j) {
        G4int Z = G4lrint((*theElementVector)[j]->GetZ());
        if(Z < 1)        { Z = 1; }
        else if(Z > maxZ){ Z = maxZ; }
 
        if( (!data[Z]) ) { ReadData(Z, path); }
      }
    }
    
    // For Doppler broadening
    if(!shellData) {
      shellData = new G4ShellData(); 
      shellData->SetOccupancyData();
      G4String file = "/doppler/shell-doppler";
      shellData->LoadData(file);
    }
    if(!profileData) { profileData = new G4DopplerProfile(); }
 
    // Scattering Function 
    if(!scatterFunctionData)
      {
    
    G4VDataSetAlgorithm* scatterInterpolation = new G4LogLogInterpolation;
    G4String scatterFile = "comp/ce-sf-";
    scatterFunctionData = new G4CompositeEMDataSet(scatterInterpolation, 1., 1.);
    scatterFunctionData->LoadData(scatterFile);
      }
    
    InitialiseElementSelectors(particle, cuts);
  }
 
  if (verboseLevel > 2) {
    G4cout << "Loaded cross section files" << G4endl;
  }
  
  if( verboseLevel>1 ) { 
    G4cout << "G4LivermoreComptonModel is initialized " << G4endl
       << "Energy range: "
       << LowEnergyLimit() / eV << " eV - "
       << HighEnergyLimit() / GeV << " GeV"
       << G4endl;
  }
  //  
  if(isInitialised) { return; }
  
  fParticleChange = GetParticleChangeForGamma();
  fAtomDeexcitation  = G4LossTableManager::Instance()->AtomDeexcitation();
  isInitialised = true;
}

◆ InitialiseForElement()

void G4LivermorePolarizedComptonModel::InitialiseForElement	(	const G4ParticleDefinition *	,
		G4int	Z )

overridevirtual

Reimplemented from G4VEmModel.

Definition at line 954 of file G4LivermorePolarizedComptonModel.cc.

{
  G4AutoLock l(&LivermorePolarizedComptonModelMutex);
  if(!data[Z]) { ReadData(Z); }
  l.unlock();
}

Referenced by ComputeCrossSectionPerAtom().

◆ InitialiseLocal()

void G4LivermorePolarizedComptonModel::InitialiseLocal	(	const G4ParticleDefinition *	,
		G4VEmModel *	masterModel )

overridevirtual

Reimplemented from G4VEmModel.

Definition at line 201 of file G4LivermorePolarizedComptonModel.cc.

{
  SetElementSelectors(masterModel->GetElementSelectors());
}

◆ operator=()

G4LivermorePolarizedComptonModel & G4LivermorePolarizedComptonModel::operator= ( const G4LivermorePolarizedComptonModel & right )

delete

◆ SampleSecondaries()

void G4LivermorePolarizedComptonModel::SampleSecondaries	(	std::vector< G4DynamicParticle * > *	fvect,
		const G4MaterialCutsCouple *	couple,
		const G4DynamicParticle *	aDynamicGamma,
		G4double	tmin,
		G4double	maxEnergy )

overridevirtual

Implements G4VEmModel.

Definition at line 300 of file G4LivermorePolarizedComptonModel.cc.

{
  // The scattered gamma energy is sampled according to Klein - Nishina formula.
  // The random number techniques of Butcher & Messel are used (Nuc Phys 20(1960),15).
  // GEANT4 internal units
  //
  // Note : Effects due to binding of atomic electrons are negliged.
 
  if (verboseLevel > 3)
    G4cout << "Calling SampleSecondaries() of G4LivermorePolarizedComptonModel" << G4endl;
 
  G4double gammaEnergy0 = aDynamicGamma->GetKineticEnergy();
 
  // do nothing below the threshold
  // should never get here because the XS is zero below the limit
  if (gammaEnergy0 < LowEnergyLimit())     
    return ; 
 
  G4ThreeVector gammaPolarization0 = aDynamicGamma->GetPolarization();
 
  // Protection: a polarisation parallel to the
  // direction causes problems;
  // in that case find a random polarization
  G4ThreeVector gammaDirection0 = aDynamicGamma->GetMomentumDirection();
 
  // Make sure that the polarization vector is perpendicular to the
  // gamma direction. If not
  if(!(gammaPolarization0.isOrthogonal(gammaDirection0, 1e-6))||(gammaPolarization0.mag()==0))
    { // only for testing now
      gammaPolarization0 = GetRandomPolarization(gammaDirection0);
    }
  else
    {
      if ( gammaPolarization0.howOrthogonal(gammaDirection0) != 0)
    {
      gammaPolarization0 = GetPerpendicularPolarization(gammaDirection0, gammaPolarization0);
    }
    }
  // End of Protection
 
  G4double E0_m = gammaEnergy0 / electron_mass_c2 ;
 
  // Select randomly one element in the current material
  //G4int Z = crossSectionHandler->SelectRandomAtom(couple,gammaEnergy0);
  const G4ParticleDefinition* particle =  aDynamicGamma->GetDefinition();
  const G4Element* elm = SelectRandomAtom(couple,particle,gammaEnergy0);
  G4int Z = (G4int)elm->GetZ();
 
  // Sample the energy and the polarization of the scattered photon
  G4double epsilon, epsilonSq, onecost, sinThetaSqr, greject ;
 
  G4double epsilon0Local = 1./(1. + 2*E0_m);
  G4double epsilon0Sq = epsilon0Local*epsilon0Local;
  G4double alpha1   = - G4Log(epsilon0Local);
  G4double alpha2 = 0.5*(1.- epsilon0Sq);
 
  G4double wlGamma = h_Planck*c_light/gammaEnergy0;
  G4double gammaEnergy1;
  G4ThreeVector gammaDirection1;
 
  do {
    if ( alpha1/(alpha1+alpha2) > G4UniformRand() )
      {
    epsilon   = G4Exp(-alpha1*G4UniformRand());  
    epsilonSq = epsilon*epsilon; 
      }
    else 
      {
    epsilonSq = epsilon0Sq + (1.- epsilon0Sq)*G4UniformRand();
    epsilon   = std::sqrt(epsilonSq);
      }
 
    onecost = (1.- epsilon)/(epsilon*E0_m);
    sinThetaSqr   = onecost*(2.-onecost);
 
    // Protection
    if (sinThetaSqr > 1.)
      {
    G4cout
      << " -- Warning -- G4LivermorePolarizedComptonModel::SampleSecondaries "
      << "sin(theta)**2 = "
      << sinThetaSqr
      << "; set to 1"
      << G4endl;
    sinThetaSqr = 1.;
      }
    if (sinThetaSqr < 0.)
      {
    G4cout
      << " -- Warning -- G4LivermorePolarizedComptonModel::SampleSecondaries "
      << "sin(theta)**2 = "
      << sinThetaSqr
      << "; set to 0"
      << G4endl;
    sinThetaSqr = 0.;
      }
    // End protection
 
    G4double x =  std::sqrt(onecost/2.) / (wlGamma/cm);;
    G4double scatteringFunction = scatterFunctionData->FindValue(x,Z-1);
    greject = (1. - epsilon*sinThetaSqr/(1.+ epsilonSq))*scatteringFunction;
 
  } while(greject < G4UniformRand()*Z);
 
 
  // ****************************************************
  //        Phi determination
  // ****************************************************
  G4double phi = SetPhi(epsilon,sinThetaSqr);
 
  //
  // scattered gamma angles. ( Z - axis along the parent gamma)
  //
  G4double cosTheta = 1. - onecost;
 
  // Protection
  if (cosTheta > 1.)
    {
      G4cout
    << " -- Warning -- G4LivermorePolarizedComptonModel::SampleSecondaries "
    << "cosTheta = "
    << cosTheta
    << "; set to 1"
    << G4endl;
      cosTheta = 1.;
    }
  if (cosTheta < -1.)
    {
      G4cout 
    << " -- Warning -- G4LivermorePolarizedComptonModel::SampleSecondaries "
    << "cosTheta = " 
    << cosTheta
    << "; set to -1"
    << G4endl;
      cosTheta = -1.;
    }
  // End protection      
 
  G4double sinTheta = std::sqrt (sinThetaSqr);
  
  // Protection
  if (sinTheta > 1.)
    {
      G4cout 
    << " -- Warning -- G4LivermorePolarizedComptonModel::SampleSecondaries "
    << "sinTheta = " 
    << sinTheta
    << "; set to 1"
    << G4endl;
      sinTheta = 1.;
    }
  if (sinTheta < -1.)
    {
      G4cout 
    << " -- Warning -- G4LivermorePolarizedComptonModel::SampleSecondaries "
    << "sinTheta = " 
    << sinTheta
    << "; set to -1" 
    << G4endl;
      sinTheta = -1.;
    }
  // End protection
  
  // Check for entanglement and re-sample phi if necessary
  
  const auto* auxInfo
  = fParticleChange->GetCurrentTrack()->GetAuxiliaryTrackInformation(fEntanglementModelID);
  if (auxInfo) {
    const auto* entanglementAuxInfo = dynamic_cast<const G4EntanglementAuxInfo*>(auxInfo);
    if (entanglementAuxInfo) {
      auto* clipBoard = dynamic_cast<G4eplusAnnihilationEntanglementClipBoard*>
      (entanglementAuxInfo->GetEntanglementClipBoard());
      if (clipBoard) {
        // This is an entangled photon from eplus annihilation at rest.
        // If this is the first scatter of the first photon, place theta and
        // phi on the clipboard.
        // If this is the first scatter of the second photon, use theta and
        // phi of the first scatter of the first photon, together with the
        // theta of the second photon, to sample phi.
        if (clipBoard->IsTrack1Measurement()) {
          // Check we have the relevant track. Not sure this is strictly
          // necessary but I want to be sure tracks from, say, more than one
          // entangled system are properly paired.
          // Note: the tracking manager pops the tracks in the reverse order. We
          // will rely on that.  (If not, the logic here would have to be a bit
          // more complicated to ensure we matched the right tracks.)
          // So our track 1 is clipboard track B.
          if (clipBoard->GetTrackB() == fParticleChange->GetCurrentTrack()) {
            // This is the first scatter of the first photon. Reset flag.
            //            // Debug
            //            auto* track1 = fParticleChange->GetCurrentTrack();
            //            G4cout
            //            << "This is the first scatter of the first photon. Reset flag."
            //            << "\nTrack: " << track1->GetTrackID()
            //            << ", Parent: " << track1->GetParentID()
            //            << ", Name: " << clipBoard->GetParentParticleDefinition()->GetParticleName()
            //            << G4endl;
            //            // End debug
            clipBoard->ResetTrack1Measurement();
            // Store cos(theta),phi of first photon.
            clipBoard->SetComptonCosTheta1(cosTheta);
            clipBoard->SetComptonPhi1(phi);
          }
        } else if (clipBoard->IsTrack2Measurement()) {
          // Check we have the relevant track.
          // Remember our track 2 is clipboard track A.
          if (clipBoard->GetTrackA() == fParticleChange->GetCurrentTrack()) {
            // This is the first scatter of the second photon. Reset flag.
            //            // Debug
            //            auto* track2 = fParticleChange->GetCurrentTrack();
            //            G4cout
            //            << "This is the first scatter of the second photon. Reset flag."
            //            << "\nTrack: " << track2->GetTrackID()
            //            << ", Parent: " << track2->GetParentID()
            //            << ", Name: " << clipBoard->GetParentParticleDefinition()->GetParticleName()
            //            << G4endl;
            //            // End debug
            clipBoard->ResetTrack2Measurement();
            
            // Get cos(theta),phi of first photon.
            const G4double& cosTheta1 = clipBoard->GetComptonCosTheta1();
            const G4double& phi1 = clipBoard->GetComptonPhi1();
            // For clarity make aliases for the current cos(theta),phi.
            const G4double& cosTheta2 = cosTheta;
            G4double& phi2 = phi;
            //            G4cout << "cosTheta1,phi1: " << cosTheta1 << ',' << phi1 << G4endl;
            //            G4cout << "cosTheta2,phi2: " << cosTheta2 << ',' << phi2 << G4endl;
            
            // Re-sample phi
            // Draw the difference of azimuthal angles, deltaPhi, from
            // A + B * cos(2*deltaPhi), or rather C + D * cos(2*deltaPhi), where
            // C = A / (A + |B|) and D = B / (A + |B|), so that maximum is 1.
            const G4double sin2Theta1 = 1.-cosTheta1*cosTheta1;
            const G4double sin2Theta2 = 1.-cosTheta2*cosTheta2;
            
            // Pryce and Ward, Nature No 4065 (1947) p.435.
            auto* g4Pow = G4Pow::GetInstance();
            const G4double A =
            ((g4Pow->powN(1.-cosTheta1,3))+2.)*(g4Pow->powN(1.-cosTheta2,3)+2.)/
            ((g4Pow->powN(2.-cosTheta1,3)*g4Pow->powN(2.-cosTheta2,3)));
            const G4double B = -(sin2Theta1*sin2Theta2)/
            ((g4Pow->powN(2.-cosTheta1,2)*g4Pow->powN(2.-cosTheta2,2)));
 
            //    // Snyder et al, Physical Review 73 (1948) p.440.
            //    // (This is an alternative formulation but result is identical.)
            //    const G4double& k0 = gammaEnergy0;
            //    const G4double k1 = k0/(2.-cosTheta1);
            //    const G4double k2 = k0/(2.-cosTheta2);
            //    const G4double gamma1 = k1/k0+k0/k1;
            //    const G4double gamma2 = k2/k0+k0/k2;
            //    const G4double A1 = gamma1*gamma2-gamma1*sin2Theta2-gamma2*sin2Theta1;
            //    const G4double B1 = 2.*sin2Theta1*sin2Theta2;
            //    // That's A1 + B1*sin2(deltaPhi) = A1 + B1*(0.5*(1.-cos(2.*deltaPhi).
            //    const G4double A = A1 + 0.5*B1;
            //    const G4double B = -0.5*B1;
            
            const G4double maxValue = A + std::abs(B);
            const G4double C = A / maxValue;
            const G4double D = B / maxValue;
            //    G4cout << "A,B,C,D: " << A << ',' << B  << ',' << C << ',' << D << G4endl;
            
            // Sample delta phi
            G4double deltaPhi;
            const G4int maxCount = 999999;
            G4int iCount = 0;
            for (; iCount < maxCount; ++iCount) {
              deltaPhi = twopi * G4UniformRand();
              if (G4UniformRand() < C + D * cos(2.*deltaPhi)) break;
            }
            if (iCount >= maxCount ) {
              G4cout << "G4LivermorePolarizedComptonModel::SampleSecondaries: "
              << "Re-sampled delta phi not found in " << maxCount
              << " tries - carrying on anyway." << G4endl;
            }
            
            // Thus, the desired second photon azimuth
            phi2 = deltaPhi - phi1 + halfpi;
            // The minus sign is in above statement because, since the two
            // annihilation photons are in opposite directions, their phi's
            // are measured in the opposite direction.
            // halfpi is added for the following reason:
            // In this function phi is relative to the polarisation - see
            // SystemOfRefChange below. We know from G4eplusAnnihilation that
            // the polarisations of the two annihilation photons are perpendicular
            // to each other, i.e., halfpi different.
            // Furthermore, only sin(phi) and cos(phi) are used below so no
            // need to place any range constraints.
            //            if (phi2 > pi) {
            //              phi2 -= twopi;
            //            }
            //            if (phi2 < -pi) {
            //              phi2 += twopi;
            //            }
          }
        }
      }
    }
  }
  
  // End of entanglement
      
  G4double dirx = sinTheta*std::cos(phi);
  G4double diry = sinTheta*std::sin(phi);
  G4double dirz = cosTheta ;
 
  // oneCosT , eom
 
  // Doppler broadening -  Method based on:
  // Y. Namito, S. Ban and H. Hirayama, 
  // "Implementation of the Doppler Broadening of a Compton-Scattered Photon Into the EGS4 Code" 
  // NIM A 349, pp. 489-494, 1994
  
  // Maximum number of sampling iterations
  static G4int maxDopplerIterations = 1000;
  G4double bindingE = 0.;
  G4double photonEoriginal = epsilon * gammaEnergy0;
  G4double photonE = -1.;
  G4int iteration = 0;
  G4double eMax = gammaEnergy0;
 
  G4int shellIdx = 0;
 
  if (verboseLevel > 3) {
    G4cout << "Started loop to sample broading" << G4endl;
  }
 
  do
    {
      iteration++;
      // Select shell based on shell occupancy
      shellIdx = shellData->SelectRandomShell(Z);
      bindingE = shellData->BindingEnergy(Z,shellIdx);
      
      if (verboseLevel > 3) {
    G4cout << "Shell ID= " << shellIdx 
           << " Ebind(keV)= " << bindingE/keV << G4endl;
      }
      eMax = gammaEnergy0 - bindingE;
      
      // Randomly sample bound electron momentum (memento: the data set is in Atomic Units)
      G4double pSample = profileData->RandomSelectMomentum(Z,shellIdx);
 
      if (verboseLevel > 3) {
       G4cout << "pSample= " << pSample << G4endl;
     }
      // Rescale from atomic units
      G4double pDoppler = pSample * fine_structure_const;
      G4double pDoppler2 = pDoppler * pDoppler;
      G4double var2 = 1. + onecost * E0_m;
      G4double var3 = var2*var2 - pDoppler2;
      G4double var4 = var2 - pDoppler2 * cosTheta;
      G4double var = var4*var4 - var3 + pDoppler2 * var3;
      if (var > 0.)
    {
      G4double varSqrt = std::sqrt(var);        
      G4double scale = gammaEnergy0 / var3;  
          // Random select either root
      if (G4UniformRand() < 0.5) photonE = (var4 - varSqrt) * scale;               
      else photonE = (var4 + varSqrt) * scale;
    } 
      else
    {
      photonE = -1.;
    }
   } while ( iteration <= maxDopplerIterations && 
         (photonE < 0. || photonE > eMax || photonE < eMax*G4UniformRand()) );
 
  // End of recalculation of photon energy with Doppler broadening
  // Revert to original if maximum number of iterations threshold has been reached
  if (iteration >= maxDopplerIterations)
    {
      photonE = photonEoriginal;
      bindingE = 0.;
    }
 
  gammaEnergy1 = photonE;
 
  //
  // update G4VParticleChange for the scattered photon 
  //
  // New polarization
  G4ThreeVector gammaPolarization1 = SetNewPolarization(epsilon,
                            sinThetaSqr,
                            phi,
                            cosTheta);
 
  // Set new direction
  G4ThreeVector tmpDirection1( dirx,diry,dirz );
  gammaDirection1 = tmpDirection1;
 
  // Change reference frame.
  SystemOfRefChange(gammaDirection0,gammaDirection1,
            gammaPolarization0,gammaPolarization1);
 
  if (gammaEnergy1 > 0.)
    {
      fParticleChange->SetProposedKineticEnergy( gammaEnergy1 ) ;
      fParticleChange->ProposeMomentumDirection( gammaDirection1 );
      fParticleChange->ProposePolarization( gammaPolarization1 );
    }
  else
    {
      gammaEnergy1 = 0.;
      fParticleChange->SetProposedKineticEnergy(0.) ;
      fParticleChange->ProposeTrackStatus(fStopAndKill);
    }
 
  //
  // kinematic of the scattered electron
  //
  G4double ElecKineEnergy = gammaEnergy0 - gammaEnergy1 -bindingE;
 
  // SI -protection against negative final energy: no e- is created
  // like in G4LivermoreComptonModel.cc
  if(ElecKineEnergy < 0.0) {
    fParticleChange->ProposeLocalEnergyDeposit(gammaEnergy0 - gammaEnergy1);
    return;
  }
 
  G4double ElecMomentum = std::sqrt(ElecKineEnergy*(ElecKineEnergy+2.*electron_mass_c2));
 
  G4ThreeVector ElecDirection((gammaEnergy0 * gammaDirection0 -
                   gammaEnergy1 * gammaDirection1) * (1./ElecMomentum));
 
  G4DynamicParticle* dp = 
    new G4DynamicParticle (G4Electron::Electron(),ElecDirection.unit(),ElecKineEnergy) ;
  fvect->push_back(dp);
 
  // sample deexcitation
  //  
  if (verboseLevel > 3) {
    G4cout << "Started atomic de-excitation " << fAtomDeexcitation << G4endl;
  }
  
  if(fAtomDeexcitation && iteration < maxDopplerIterations) {
    G4int index = couple->GetIndex();
    if(fAtomDeexcitation->CheckDeexcitationActiveRegion(index)) {
      std::size_t nbefore = fvect->size();
      G4AtomicShellEnumerator as = G4AtomicShellEnumerator(shellIdx);
      const G4AtomicShell* shell = fAtomDeexcitation->GetAtomicShell(Z, as);
      fAtomDeexcitation->GenerateParticles(fvect, shell, Z, index);
      std::size_t nafter = fvect->size();
      if(nafter > nbefore) {
    for (std::size_t i=nbefore; i<nafter; ++i) {
      //Check if there is enough residual energy 
      if (bindingE >= ((*fvect)[i])->GetKineticEnergy())
            {
              //Ok, this is a valid secondary: keep it
          bindingE -= ((*fvect)[i])->GetKineticEnergy();
            }
      else
            {
          //Invalid secondary: not enough energy to create it!
          //Keep its energy in the local deposit
          delete (*fvect)[i]; 
              (*fvect)[i]=0;
            }
    } 
      }
    }
  }
  //This should never happen
  if(bindingE < 0.0) 
    G4Exception("G4LivermoreComptonModel::SampleSecondaries()",
        "em2050",FatalException,"Negative local energy deposit");   
  
  fParticleChange->ProposeLocalEnergyDeposit(bindingE);
 
}

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

Public Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ G4LivermorePolarizedComptonModel() [1/2]

◆ ~G4LivermorePolarizedComptonModel()

◆ G4LivermorePolarizedComptonModel() [2/2]

Member Function Documentation

◆ ComputeCrossSectionPerAtom()

◆ Initialise()

◆ InitialiseForElement()

◆ InitialiseLocal()

◆ operator=()

◆ SampleSecondaries()