G4NuDEXNeutronCaptureModel Class Reference

#include <G4NuDEXNeutronCaptureModel.hh>

Inheritance diagram for G4NuDEXNeutronCaptureModel:

Public Member Functions
	G4NuDEXNeutronCaptureModel ()
virtual	~G4NuDEXNeutronCaptureModel ()
virtual G4HadFinalState *	ApplyYourself (const G4HadProjectile &aTrack, G4Nucleus &targetNucleus) final
virtual void	InitialiseModel () final
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 &aTrack, G4Nucleus &targetNucleus)
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)
G4int	GetVerboseLevel () const
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
virtual const std::pair< G4double, G4double >	GetFatalEnergyCheckLevels () const
virtual std::pair< G4double, G4double >	GetEnergyMomentumCheckLevels () const
void	SetEnergyMomentumCheckLevels (G4double relativeLevel, G4double absoluteLevel)
virtual void	ModelDescription (std::ostream &outFile) const
virtual void	BuildPhysicsTable (const G4ParticleDefinition &)
	G4HadronicInteraction (const G4HadronicInteraction &right)=delete
const G4HadronicInteraction &	operator= (const G4HadronicInteraction &right)=delete
G4bool	operator== (const G4HadronicInteraction &right) const =delete
G4bool	operator!= (const G4HadronicInteraction &right) const =delete

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 67 of file G4NuDEXNeutronCaptureModel.hh.

Constructor & Destructor Documentation

G4NuDEXNeutronCaptureModel()

G4NuDEXNeutronCaptureModel::G4NuDEXNeutronCaptureModel ( )

explicit

Definition at line 73 of file G4NuDEXNeutronCaptureModel.cc.

                                                       : G4HadronicInteraction( "nuDEX_neutronCapture" ) {
  for ( G4int i = 0; i < G4NUDEX_MAXZA; i++ ) {
    theStatisticalNucleus[i] = nullptr;
    HasData[i] = 0;
  }
  BrOption = -1;
  BandWidth = 0;
  NuDEXLibDirectory = "";
  photonEvaporation = nullptr;
  auto ch = G4FindDataDir( "G4NUDEXLIBDATA" );
  if ( ch == nullptr ) {
    G4Exception( "G4NuDEXNeutronCaptureModel()", "had0707", FatalException, "Environment variable G4NUDEXLIBDATA is not defined" );
  } else {
    NuDEXLibDirectory = G4String(ch);
  }
}

~G4NuDEXNeutronCaptureModel()

G4NuDEXNeutronCaptureModel::~G4NuDEXNeutronCaptureModel ( )

virtual

Definition at line 104 of file G4NuDEXNeutronCaptureModel.cc.

                                                       {
  for ( G4int i = 0; i < G4NUDEX_MAXZA; i++ ) {
    if ( theStatisticalNucleus[i] ) delete theStatisticalNucleus[i];
  }
}

Member Function Documentation

ApplyYourself()

G4HadFinalState * G4NuDEXNeutronCaptureModel::ApplyYourself ( const G4HadProjectile & aTrack, G4Nucleus & targetNucleus )

finalvirtual

Reimplemented from G4HadronicInteraction.

Definition at line 111 of file G4NuDEXNeutronCaptureModel.cc.

                                                                                                                 {
  theParticleChange.Clear();
  theParticleChange.SetStatusChange( stopAndKill );
  G4int A = theNucleus.GetA_asInt();
  G4int Z = theNucleus.GetZ_asInt();
  G4double time = aTrack.GetGlobalTime();  // Time in the lab frame
  // Create initial state
  G4LorentzVector lab4mom( 0.0, 0.0, 0.0, G4NucleiProperties::GetNuclearMass(A, Z) );
  lab4mom += aTrack.Get4Momentum();
  G4double systemMass = lab4mom.mag();
  ++A;  // Compound nucleus: target nucleus + neutron
  G4double compoundMass = G4NucleiProperties::GetNuclearMass(A, Z);
  // If the energy available is to small to do anything interesting, gives up
  if ( systemMass - compoundMass  <= lowestEnergyLimit ) return &theParticleChange;
  G4ThreeVector boostFromCMtoLAB = lab4mom.boostVector();
  G4double neutronEnergy = aTrack.GetKineticEnergy();
 
  // Try to apply NuDEX
  //G4int lspin = 0;     // l-spin = 0, 1, 2 --> s-wave, p-wave, d-wave ... 
  //G4int jspinx2 = -1;  // A negative value of jspinx2 means that is sampled according to the 2J+1 rule.
  //G4int initialLevel = SelectInitialLevel( Z, A, neutronEnergy, lspin, jspinx2 );
  G4int initialLevel = -1;  // thermal neutron capture
  std::vector< char > pType;
  std::vector< G4double > pEnergy, pTime;
  G4int npar = GenerateNeutronCaptureCascade( Z, A, neutronEnergy, initialLevel, pType, pEnergy, pTime );
  if ( npar > 0 ) {  // NuDEX can be applied
    
    G4LorentzVector remainingLab4mom = lab4mom;
    G4double latestEmission = time;
    // Loop over the EM particles produced by 'GenerateNeutronCaptureCascade' and add them to the
    // theParticleChange as secondaries. These particles are produced by NuDEX in the nucleus' rest-frame.
    for ( G4int i = 0; i < npar; i++ ) {
      G4ParticleDefinition* particleDef = nullptr;
      if ( pType.at(i) == 'g' ) {
        particleDef = G4Gamma::Definition();
      } else if  (pType.at(i) == 'e' ) {
        particleDef = G4Electron::Definition();
      } else if ( pType.at(i) == 'p' ) {
        particleDef = G4Positron::Definition();
      } else {
        G4Exception( "G4NUDEXNeutronCaptureModel::ApplyYourself()", "had0707", FatalException, "Unknown particle type" );
      }
      G4double phi = G4UniformRand()*twopi;
      G4double costheta = 2.0*G4UniformRand() - 1.0;
      G4double sintheta = std::sqrt( 1.0 - costheta*costheta );
      G4ThreeVector direction( sintheta*std::cos(phi), sintheta*std::sin(phi), costheta );
      G4double mass = particleDef->GetPDGMass();
      G4double particle3momMod = std::sqrt( pEnergy.at(i) * ( pEnergy.at(i) + 2.0*mass ) );
      G4LorentzVector particle4mom( particle3momMod*direction, mass + pEnergy.at(i) );  // In the center-of-mass frame
      particle4mom.boost( boostFromCMtoLAB );  // Now in the Lab frame
      G4HadSecondary* secondary = new G4HadSecondary( new G4DynamicParticle( particleDef, particle4mom ) );
      remainingLab4mom -= particle4mom;
      // For simplicity, we neglect below the different frames of time (Lab) and pTime (center-of-mass) 
      secondary->SetTime( time + pTime.at(i) );
      if ( latestEmission < time + pTime.at(i) ) latestEmission = time + pTime.at(i);
      secondary->SetCreatorModelID( secID );
      theParticleChange.AddSecondary( *secondary );
      delete secondary;
    }
    // Treat now the residual nucleus (which is neglected by NuDEX)
    const G4ParticleDefinition* resNuclDef = nullptr;
    if      ( Z == 1  &&  A == 2 ) resNuclDef = G4Deuteron::Definition();
    else if ( Z == 1  &&  A == 3 ) resNuclDef = G4Triton::Definition();
    else if ( Z == 2  &&  A == 3 ) resNuclDef = G4He3::Definition();
    else if ( Z == 2  &&  A == 4 ) resNuclDef = G4Alpha::Alpha();
    else resNuclDef = G4ParticleTable::GetParticleTable()->GetIonTable()->GetIon( Z, A, 0.0, noFloat, 0 );
    if ( resNuclDef ) {
      // To conserve energy-momentum, remainingLab4mom should be the Lorentz 4-momentum of the residual nucleus.
      // Imposing the mass 'compoundMass' to the residual nucleus, and trying to conserve the total energy
      // while keeping as low as possible the violation of the 3-momentum; in the case that the total energy
      // cannot be conserved, the residual nucleus is produced at rest (in the Lab frame).
      G4double resNuclLabEkin = std::max( remainingLab4mom.e() - compoundMass, 0.0 );
      G4double resNuclLab3momMod = 0.0;
      G4ThreeVector resNuclLabDir( 0.0, 0.0, 0.0 );
      if ( resNuclLabEkin > 0.0 ) {
        resNuclLab3momMod = std::sqrt( resNuclLabEkin * ( resNuclLabEkin + 2.0*compoundMass ) );
        resNuclLabDir = remainingLab4mom.vect().unit();
      }
      G4LorentzVector resNuclLab4mom( resNuclLab3momMod*resNuclLabDir, resNuclLabEkin + compoundMass );
      G4HadSecondary* secondary = new G4HadSecondary( new G4DynamicParticle( resNuclDef, resNuclLab4mom ) );
      secondary->SetTime( latestEmission );
      secondary->SetCreatorModelID( secID );
      theParticleChange.AddSecondary( *secondary );
      delete secondary;
    }
 
  } else {  // NuDEX cannot be applied: use G4PhotonEvaporation
 
    // Code taken from G4NeutronRadCapture
 
    G4Fragment* aFragment = new G4Fragment( A, Z, lab4mom );
    G4FragmentVector* fv = photonEvaporation->BreakUpFragment( aFragment );
    if ( fv == nullptr ) fv = new G4FragmentVector;
    fv->push_back( aFragment );
    size_t n = fv->size();
    for ( size_t i = 0; i < n; ++i ) {
      G4Fragment* f = (*fv)[i];    
      G4double etot = f->GetMomentum().e();
      Z = f->GetZ_asInt();
      A = f->GetA_asInt();
      const G4ParticleDefinition* theDef = nullptr;
      if      ( Z == 0  && A == 0 ) { theDef = f->GetParticleDefinition(); }
      else if ( Z == 1  && A == 2 ) { theDef = G4Deuteron::Definition(); }
      else if ( Z == 1  && A == 3 ) { theDef = G4Triton::Definition(); }
      else if ( Z == 2  && A == 3 ) { theDef = G4He3::Definition(); }
      else if ( Z == 2  && A == 4 ) { theDef = G4Alpha::Definition(); }
      else {
        G4double eexc = f->GetExcitationEnergy();
        if ( eexc <= minExcitation ) eexc = 0.0;
        theDef = G4ParticleTable::GetParticleTable()->GetIonTable()->GetIon( Z, A, eexc, noFloat, 0 );
      }
      G4double ekin = std::max( 0.0, etot - theDef->GetPDGMass() );
      G4HadSecondary* news = new G4HadSecondary( new G4DynamicParticle( theDef, f->GetMomentum().vect().unit(), ekin ) );
      G4double timeF = f->GetCreationTime();
      if ( timeF < 0.0 ) timeF = 0.0;
      news->SetTime( time + timeF );
      news->SetCreatorModelID( secID );
      theParticleChange.AddSecondary( *news );
      delete news;
      delete f;
    }
    delete fv;
  }
  
  return &theParticleChange;
}

InitialiseModel()

void G4NuDEXNeutronCaptureModel::InitialiseModel ( )

finalvirtual

Reimplemented from G4HadronicInteraction.

Definition at line 91 of file G4NuDEXNeutronCaptureModel.cc.

                                                 {
  if ( photonEvaporation != nullptr ) return;
  G4DeexPrecoParameters* param = G4NuclearLevelData::GetInstance()->GetParameters();
  minExcitation = param->GetMinExcitation();
  photonEvaporation = new G4PhotonEvaporation;
  photonEvaporation->Initialise();
  photonEvaporation->SetICM( true );
  secID = G4PhysicsModelCatalog::GetModelID( "model_" + GetModelName() );
  lowestEnergyLimit = 10.0*CLHEP::eV;
  minExcitation = 0.1*CLHEP::keV;
}

---

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

• G4NuDEXNeutronCaptureModel.hh
• G4NuDEXNeutronCaptureModel.cc