G4PreCompoundModel Class Reference

#include <G4PreCompoundModel.hh>

Inheritance diagram for G4PreCompoundModel:

Public Member Functions
	G4PreCompoundModel (G4ExcitationHandler *ptr=nullptr)
virtual	~G4PreCompoundModel ()
virtual G4HadFinalState *	ApplyYourself (const G4HadProjectile &thePrimary, G4Nucleus &theNucleus) final
virtual G4ReactionProductVector *	DeExcite (G4Fragment &aFragment) final
virtual void	BuildPhysicsTable (const G4ParticleDefinition &) final
virtual void	InitialiseModel () final
virtual void	ModelDescription (std::ostream &outFile) const final
virtual void	DeExciteModelDescription (std::ostream &outFile) const final
Public Member Functions inherited from G4VPreCompoundModel
	G4VPreCompoundModel (G4ExcitationHandler *ptr=nullptr, const G4String &modelName="PrecompoundModel")
virtual	~G4VPreCompoundModel ()
void	SetExcitationHandler (G4ExcitationHandler *ptr)
G4ExcitationHandler *	GetExcitationHandler () const
	G4VPreCompoundModel (const G4VPreCompoundModel &)=delete
const G4VPreCompoundModel &	operator= (const G4VPreCompoundModel &right)=delete
G4bool	operator== (const G4VPreCompoundModel &right) const =delete
G4bool	operator!= (const G4VPreCompoundModel &right) const =delete
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)
	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 62 of file G4PreCompoundModel.hh.

Constructor & Destructor Documentation

G4PreCompoundModel()

G4PreCompoundModel::G4PreCompoundModel ( G4ExcitationHandler * ptr = nullptr )

explicit

Definition at line 70 of file G4PreCompoundModel.cc.

  : G4VPreCompoundModel(ptr,"PRECO")
{
  //G4cout << "### NEW PrecompoundModel " << this << G4endl;
  if(nullptr == ptr) { SetExcitationHandler(new G4ExcitationHandler()); }
 
  fNuclData = G4NuclearLevelData::GetInstance();
  proton = G4Proton::Proton();
  neutron = G4Neutron::Neutron();
  modelID = G4PhysicsModelCatalog::GetModelID("model_PRECO");
}

~G4PreCompoundModel()

G4PreCompoundModel::~G4PreCompoundModel ( )

virtual

Definition at line 84 of file G4PreCompoundModel.cc.

{
  delete theEmission;
  delete theTransition;
  delete GetExcitationHandler();
  theResult.Clear();
}

Member Function Documentation

ApplyYourself()

G4HadFinalState * G4PreCompoundModel::ApplyYourself ( const G4HadProjectile & thePrimary, G4Nucleus & theNucleus )

finalvirtual

Reimplemented from G4HadronicInteraction.

Definition at line 135 of file G4PreCompoundModel.cc.

{  
  const G4ParticleDefinition* primary = thePrimary.GetDefinition();
  if(primary != neutron && primary != proton) {
    G4ExceptionDescription ed;
    ed << "G4PreCompoundModel is used for ";
    if(primary) { ed << primary->GetParticleName(); }
    G4Exception("G4PreCompoundModel::ApplyYourself()","had0033",FatalException,
                ed,"");
    return nullptr;
  }
 
  G4int Zp = 0;
  G4int Ap = 1;
  if(primary == proton) { Zp = 1; }
 
  G4double timePrimary=thePrimary.GetGlobalTime();
 
  G4int A = theNucleus.GetA_asInt();
  G4int Z = theNucleus.GetZ_asInt();
   
  //G4cout << "### G4PreCompoundModel::ApplyYourself: A= " << A << " Z= " << Z
  //     << " Ap= " << Ap << " Zp= " << Zp << G4endl; 
  // 4-Momentum
  G4LorentzVector p = thePrimary.Get4Momentum();
  G4double mass = G4NucleiProperties::GetNuclearMass(A, Z);
  p += G4LorentzVector(0.0,0.0,0.0,mass);
  //G4cout << "Primary 4-mom " << p << "  mass= " << mass << G4endl;
 
  // prepare fragment
  G4Fragment anInitialState(A + Ap, Z + Zp, p);
  anInitialState.SetNumberOfExcitedParticle(2, 1);
  anInitialState.SetNumberOfHoles(1,0);
  anInitialState.SetCreationTime(thePrimary.GetGlobalTime());
  anInitialState.SetCreatorModelID(modelID);
  
  // call excitation handler
  G4ReactionProductVector* result = DeExcite(anInitialState);
 
  // fill particle change
  theResult.Clear();
  theResult.SetStatusChange(stopAndKill);
  for(auto const & prod : *result) {
    G4DynamicParticle * aNewDP = new G4DynamicParticle(prod->GetDefinition(),
                               prod->GetTotalEnergy(),
                               prod->GetMomentum());
    G4HadSecondary aNew = G4HadSecondary(aNewDP);
    G4double time = std::max(prod->GetFormationTime(), 0.0);
    aNew.SetTime(timePrimary + time);
    aNew.SetCreatorModelID(prod->GetCreatorModelID());
    delete prod;
    theResult.AddSecondary(aNew);
  }
  delete result;
  
  //return the filled particle change
  return &theResult;
}

BuildPhysicsTable()

void G4PreCompoundModel::BuildPhysicsTable ( const G4ParticleDefinition & )

finalvirtual

Reimplemented from G4HadronicInteraction.

Definition at line 94 of file G4PreCompoundModel.cc.

{
  InitialiseModel();
}

DeExcite()

G4ReactionProductVector * G4PreCompoundModel::DeExcite ( G4Fragment & aFragment )

finalvirtual

Implements G4VPreCompoundModel.

Definition at line 197 of file G4PreCompoundModel.cc.

{
  if(!isInitialised) { InitialiseModel(); }
 
  G4ReactionProductVector * Result = new G4ReactionProductVector;
  G4double U = aFragment.GetExcitationEnergy();
  G4int Z = aFragment.GetZ_asInt(); 
  G4int A = aFragment.GetA_asInt();
 
  //G4cout << "### G4PreCompoundModel::DeExcite" << G4endl;
  //G4cout << aFragment << G4endl;
 
  // Conditions to skip pre-compound and perform equilibrium emission 
  if (!isActive || (Z < minZ && A < minA) || 
      U < fLowLimitExc*A || U > A*fHighLimitExc ||
      0 <  aFragment.GetNumberOfLambdas()) {
    PerformEquilibriumEmission(aFragment, Result);
    return Result;
  }
  
  // main loop  
  G4int count = 0;
  const G4double ldfact = 12.0/CLHEP::pi2;
  const G4int countmax = 1000;
  for (;;) {
    //G4cout << "### PreCompound loop over fragment" << G4endl;
    //G4cout << aFragment << G4endl;
    U = aFragment.GetExcitationEnergy();
    Z = aFragment.GetZ_asInt();
    A = aFragment.GetA_asInt();
    G4int eqExcitonNumber = 
      G4lrint(std::sqrt(ldfact*U*fNuclData->GetLevelDensity(Z, A, U)));
    //   
    //    G4cout<<"Neq="<<EquilibriumExcitonNumber<<G4endl;
    //
    // J. M. Quesada (Jan. 08)  equilibrium hole number could be used as preeq.
    // evap. delimiter (IAEA report)
    
    // Loop for transitions, it is performed while there are 
    // preequilibrium transitions.
    G4bool isTransition = false;
    
    //        G4cout<<"----------------------------------------"<<G4endl;
    //        G4double NP=aFragment.GetNumberOfParticles();
    //        G4double NH=aFragment.GetNumberOfHoles();
    //        G4double NE=aFragment.GetNumberOfExcitons();
    //        G4cout<<" Ex. Energy="<<aFragment.GetExcitationEnergy()<<G4endl;
    //   G4cout<<"N. excitons="<<NE<<"  N. Part="<<NP<<"N. Holes ="<<NH<<G4endl;
    do {
      ++count;
      //G4cout<<"transition number .."<<count
      //      <<" n ="<<aFragment.GetNumberOfExcitons()<<G4endl;
      // soft cutoff criterium as an "ad-hoc" solution to force 
      // increase in  evaporation  
      G4int ne = aFragment.GetNumberOfExcitons();
      G4bool go_ahead = (ne <= eqExcitonNumber);
 
      //J. M. Quesada (Apr. 08): soft-cutoff switched off by default
      if (useSCO && go_ahead) {
    G4double x = (G4double)(ne - eqExcitonNumber)/(G4double)eqExcitonNumber;
    if( G4UniformRand() < 1.0 -  G4Exp(-x*x/0.32) ) { go_ahead = false; }
      } 
        
      // JMQ: WARNING:  CalculateProbability MUST be called prior to Get!! 
      // (O values would be returned otherwise)
      G4double transProbability = 
    theTransition->CalculateProbability(aFragment);
      G4double P1 = theTransition->GetTransitionProb1();
      G4double P2 = theTransition->GetTransitionProb2();
      G4double P3 = theTransition->GetTransitionProb3();
      //G4cout<<"#0 P1="<<P1<<" P2="<<P2<<"  P3="<<P3<<G4endl;
      
      //J.M. Quesada (May 2008) Physical criterium (lamdas)  PREVAILS over 
      //                        approximation (critical exciton number)
      //V.Ivanchenko (May 2011) added check on number of nucleons
      //                        to send a fragment to FermiBreakUp
      //                        or check on limits of excitation
      if(!go_ahead || P1 <= P2+P3 || Z < minZ || A < minA || 
         U <= fLowLimitExc*A || U > A*fHighLimitExc ||
     aFragment.GetNumberOfExcitons() <= 0) {
    // G4cout<<"#4 EquilibriumEmission"<<G4endl; 
    PerformEquilibriumEmission(aFragment,Result);
    return Result;
      }
      G4double emissionProbability = 
    theEmission->GetTotalProbability(aFragment);
      //G4cout<<"#1 TotalEmissionProbability="<<emissionProbability
      //<<" Nex= " <<aFragment.GetNumberOfExcitons()<<G4endl;
      //J.M.Quesada (May 08) this has already been done in order to decide  
      //                     what to do (preeq-eq) 
      // Sum of all probabilities
      G4double TotalProbability = emissionProbability + transProbability;
            
      // Select subprocess
      if (TotalProbability*G4UniformRand() > emissionProbability) {
    //G4cout<<"#2 Transition"<<G4endl; 
    // It will be transition to state with a new number of excitons
    isTransition = true;        
    // Perform the transition
    theTransition->PerformTransition(aFragment);
      } else {
    //G4cout<<"#3 Emission"<<G4endl; 
    // It will be fragment emission
    isTransition = false;
    Result->push_back(theEmission->PerformEmission(aFragment));
      }
      // Loop checking, 05-Aug-2015, Vladimir Ivanchenko
    } while (isTransition);   // end of do loop
 
    // stop if too many iterations
    if(count >= countmax) {
      G4ExceptionDescription ed;
      ed << "G4PreCompoundModel loop over " << countmax << " iterations; "
     << "current G4Fragment: \n" << aFragment;
      G4Exception("G4PreCompoundModel::DeExcite()","had0034",JustWarning,
          ed,"");
      PerformEquilibriumEmission(aFragment, Result);
      return Result;
    }
  } // end of for (;;) loop
  return Result;
}

Referenced by G4LowEGammaNuclearModel::ApplyYourself(), G4LowEIonFragmentation::ApplyYourself(), ApplyYourself(), and G4NeutrinoNucleusModel::RecoilDeexcitation().

DeExciteModelDescription()

void G4PreCompoundModel::DeExciteModelDescription ( std::ostream & outFile ) const

finalvirtual

Implements G4VPreCompoundModel.

Definition at line 350 of file G4PreCompoundModel.cc.

{
  outFile << "description of precompound model as used with DeExcite()" << "\n";
}

InitialiseModel()

void G4PreCompoundModel::InitialiseModel ( )

finalvirtual

Reimplemented from G4HadronicInteraction.

Definition at line 101 of file G4PreCompoundModel.cc.

{
  if(isInitialised) { return; }
  isInitialised = true;
 
  //G4cout << "G4PreCompoundModel::InitialiseModel() started" << G4endl;
 
  G4DeexPrecoParameters* param = fNuclData->GetParameters();
 
  fLowLimitExc = param->GetPrecoLowEnergy();
  fHighLimitExc = param->GetPrecoHighEnergy();
 
  useSCO = param->UseSoftCutoff();
 
  minZ = param->GetMinZForPreco();
  minA = param->GetMinAForPreco();
 
  theEmission = new G4PreCompoundEmission();
  if(param->UseHETC()) { theEmission->SetHETCModel(); }
  theEmission->SetOPTxs(param->GetPrecoModelType());
 
  if(param->UseGNASH()) { theTransition = new G4GNASHTransitions; }
  else { theTransition = new G4PreCompoundTransitions(); }
  theTransition->UseNGB(param->NeverGoBack());
  theTransition->UseCEMtr(param->UseCEM());
 
  if(param->PrecoDummy()) { isActive = false; } 
 
  GetExcitationHandler()->Initialise();
}

Referenced by BuildPhysicsTable(), and DeExcite().

ModelDescription()

void G4PreCompoundModel::ModelDescription ( std::ostream & outFile ) const

finalvirtual

Reimplemented from G4HadronicInteraction.

Definition at line 324 of file G4PreCompoundModel.cc.

{
  outFile 
    << "The GEANT4 precompound model is considered as an extension of the\n"
    <<  "hadron kinetic model. It gives a possibility to extend the low energy range\n"
    <<  "of the hadron kinetic model for nucleon-nucleus inelastic collision and it \n"
    <<  "provides a ”smooth” transition from kinetic stage of reaction described by the\n"
    <<  "hadron kinetic model to the equilibrium stage of reaction described by the\n"
    <<  "equilibrium deexcitation models.\n"
    <<  "The initial information for calculation of pre-compound nuclear stage\n"
    <<  "consists of the atomic mass number A, charge Z of residual nucleus, its\n"
    <<  "four momentum P0 , excitation energy U and number of excitons n, which equals\n"
    <<  "the sum of the number of particles p (from them p_Z are charged) and the number of\n"
    <<  "holes h.\n"
    <<  "At the preequilibrium stage of reaction, we follow the exciton model approach in ref. [1],\n"
    <<  "taking into account the competition among all possible nuclear transitions\n"
    <<  "with ∆n = +2, −2, 0 (which are defined by their associated transition probabilities) and\n"
    <<  "the emission of neutrons, protons, deuterons, thritium and helium nuclei (also defined by\n"
    <<  "their associated emission  probabilities according to exciton model)\n"
    <<  "\n"
    <<  "[1] K.K. Gudima, S.G. Mashnik, V.D. Toneev, Nucl. Phys. A401 329 (1983)\n"
    << "\n";
}

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

• G4PreCompoundModel.hh
• G4PreCompoundModel.cc