G4GammaTransition Class Reference

#include <G4GammaTransition.hh>

Public Member Functions
	G4GammaTransition ()
virtual	~G4GammaTransition ()
virtual G4Fragment *	SampleTransition (G4Fragment *nucleus, G4double newExcEnergy, G4double mpRatio, G4int JP1, G4int JP2, G4int MP, G4int shell, G4bool isDiscrete, G4bool isGamma)
virtual void	SampleDirection (G4Fragment *nuc, G4double ratio, G4int twoJ1, G4int twoJ2, G4int mp)
void	SetPolarizationFlag (G4bool val)
void	SetTwoJMAX (G4int val)
void	SetVerbose (G4int val)

Protected Attributes
G4ThreeVector	fDirection
G4PolarizationTransition	fPolTrans
G4int	fTwoJMAX
G4int	fVerbose

Detailed Description

Definition at line 52 of file G4GammaTransition.hh.

Constructor & Destructor Documentation

G4GammaTransition()

G4GammaTransition::G4GammaTransition ( )

explicit

Definition at line 48 of file G4GammaTransition.cc.

  : polarFlag(false), fDirection(0.,0.,0.), fTwoJMAX(10), fVerbose(0)
{}

~G4GammaTransition()

G4GammaTransition::~G4GammaTransition ( )

virtual

Definition at line 52 of file G4GammaTransition.cc.

{}

Member Function Documentation

SampleDirection()

void G4GammaTransition::SampleDirection ( G4Fragment * nuc, G4double ratio, G4int twoJ1, G4int twoJ2, G4int mp )

virtual

Definition at line 166 of file G4GammaTransition.cc.

{
  G4double cosTheta, phi;
  G4NuclearPolarization* np = nuc->GetNuclearPolarization(); 
  if(fVerbose > 2) {
    G4cout << "G4GammaTransition::SampleDirection : 2J1= " << twoJ1 
       << " 2J2= " << twoJ2 << " ratio= " << ratio 
       << " mp= " << mp << G4endl;
    G4cout << "  Nucleus: " << *nuc << G4endl;
  }
  if(nullptr == np) {
    cosTheta = 2*G4UniformRand() - 1.0;
    phi = CLHEP::twopi*G4UniformRand();
 
  } else {
    // PhotonEvaporation dataset:
    // The multipolarity number with 1,2,3,4,5,6,7 representing E0,E1,M1,E2,M2,E3,M3
    // monopole transition and 100*Nx+Ny representing multipolarity transition with
    // Ny and Ny taking the value 1,2,3,4,5,6,7 referring to E0,E1,M1,E2,M2,E3,M3,..
    // For example a M1+E2 transition would be written 304.
    // M1 is the primary transition (L) and E2 is the secondary (L')
 
    G4double mpRatio = ratio;
 
    G4int L0 = 0, Lp = 0;
    if (mp > 99) {
      L0 = mp/200;
      Lp = (mp%100)/2;
    } else {
      L0 = mp/2;
      Lp = 0;
      mpRatio = 0.;
    } 
    fPolTrans.SampleGammaTransition(np, twoJ1, twoJ2, L0, Lp, mpRatio, cosTheta, phi);
  }
 
  G4double sinTheta = std::sqrt((1.-cosTheta)*(1.+cosTheta));
  fDirection.set(sinTheta*std::cos(phi),sinTheta*std::sin(phi),cosTheta);
  if(fVerbose > 3) {
    G4cout << "G4GammaTransition::SampleDirection done: " << fDirection << G4endl;
    if(np) { G4cout << *np << G4endl; }
  }
}

Referenced by SampleTransition().

SampleTransition()

G4Fragment * G4GammaTransition::SampleTransition ( G4Fragment * nucleus, G4double newExcEnergy, G4double mpRatio, G4int JP1, G4int JP2, G4int MP, G4int shell, G4bool isDiscrete, G4bool isGamma )

virtual

Definition at line 56 of file G4GammaTransition.cc.

{
  G4Fragment* result = nullptr;
  G4double bondEnergy = 0.0;
  G4bool isGamma = gamma;
  if (!isDiscrete) { isGamma = true; }
 
  G4double excEnergy = nucleus->GetExcitationEnergy();
 
  // check is IC electron can be emitted 
  if (!isGamma) { 
    if(0 <= shell) {
      G4int Z = nucleus->GetZ_asInt();
      if(Z <= 104) {
    G4int idx = std::min(shell, G4AtomicShells::GetNumberOfShells(Z)-1);
    bondEnergy = G4AtomicShells::GetBindingEnergy(Z, idx);
    if (bondEnergy > excEnergy) {
      isGamma = true;
    }
      } else {
    isGamma = true;
      }
    } else {
      isGamma = true;
    }
  }
  if (fVerbose > 2) {
    G4cout << "G4GammaTransition::GenerateGamma " << " Eexnew=" << newExcEnergy 
       << " Ebond=" << bondEnergy << G4endl;
  } 
  
  // complete selection of secondary
  G4ParticleDefinition* part;
  G4int ne = nucleus->GetNumberOfElectrons();
  if (0 == ne) { isGamma = true; }
 
  if ( isGamma ) { part = G4Gamma::Gamma(); }
  else {
    part = G4Electron::Electron();
    --ne;
    nucleus->SetNumberOfElectrons(ne);
  }
 
  if (isGamma && polarFlag && isDiscrete && JP1 <= fTwoJMAX) {
    SampleDirection(nucleus, mpRatio, JP1, JP2, MP);
  } else {
    fDirection = G4RandomDirection();
  }
 
  // 4-vector of initial fragnet 
  G4LorentzVector lv = nucleus->GetMomentum();
 
  // kinematics of the decay
  G4double emass = part->GetPDGMass();
  G4double m0 = nucleus->GetGroundStateMass() + excEnergy;
  G4double m1 = nucleus->GetGroundStateMass() + newExcEnergy;
  if (!isGamma) {
    m0 += (ne + 1)*CLHEP::electron_mass_c2 - bondEnergy;
    m1 += ne*CLHEP::electron_mass_c2;
  }
 
  // 2-body decay in rest frame
  const G4double elim2 = 100.*CLHEP::eV*CLHEP::eV;
  G4bool atRest = (lv.vect().mag2() < elim2);
  G4ThreeVector bst(0.0, 0.0, 0.0);
  if (!atRest) { bst = lv.boostVector(); }
 
  //G4cout << "Ecm= " << ecm << " mass= " << mass << " emass= " << emass << G4endl;
 
  G4double energy = 0.5*((m0 - m1)*(m0 + m1) + emass*emass)/m0;
  G4double mom = (isGamma) ? energy : std::sqrt((energy - emass)*(energy + emass));
 
  // emitted gamma or e-
  G4LorentzVector res4mom(mom * fDirection.x(),
              mom * fDirection.y(),
              mom * fDirection.z(), energy);
  // residual
  energy = m0 - energy;
  mom = std::sqrt((energy - m1)*(energy + m1));
  lv.set(-mom*fDirection.x(), -mom*fDirection.y(), -mom*fDirection.z(), energy);
 
  // Lab system transform for short lived level
  if (!atRest) {
    lv.boost(bst);
    res4mom.boost(bst);
  }
 
  // modified primary fragment 
  nucleus->SetExcEnergyAndMomentum(newExcEnergy, lv);
 
  // gamma or e- are produced
  result = new G4Fragment(res4mom, part);
 
  //G4cout << " DeltaE= " << e0 - lv.e() - res4mom.e() + emass
  //     << "   Emass= " << emass << G4endl;
  if(fVerbose > 2) {
    G4cout << "G4GammaTransition::SampleTransition : " << *result << G4endl;
    G4cout << "       Left nucleus: " << *nucleus << G4endl;
  }
  return result;
}

SetPolarizationFlag()

void G4GammaTransition::SetPolarizationFlag ( G4bool val )

inline

Definition at line 73 of file G4GammaTransition.hh.

{ polarFlag = val; };

SetTwoJMAX()

void G4GammaTransition::SetTwoJMAX ( G4int val )

inline

Definition at line 75 of file G4GammaTransition.hh.

{ fTwoJMAX = val; };

SetVerbose()

void G4GammaTransition::SetVerbose ( G4int val )

inline

Definition at line 77 of file G4GammaTransition.hh.

{ fVerbose = val; fPolTrans.SetVerbose(val); };

Member Data Documentation

fDirection

G4ThreeVector G4GammaTransition::fDirection

protected

Definition at line 90 of file G4GammaTransition.hh.

Referenced by G4GammaTransition(), SampleDirection(), and SampleTransition().

fPolTrans

G4PolarizationTransition G4GammaTransition::fPolTrans

protected

Definition at line 91 of file G4GammaTransition.hh.

Referenced by SampleDirection(), and SetVerbose().

fTwoJMAX

G4int G4GammaTransition::fTwoJMAX

protected

Definition at line 92 of file G4GammaTransition.hh.

Referenced by G4GammaTransition(), SampleTransition(), and SetTwoJMAX().

fVerbose

G4int G4GammaTransition::fVerbose

protected

Definition at line 93 of file G4GammaTransition.hh.

Referenced by G4GammaTransition(), SampleDirection(), SampleTransition(), and SetVerbose().

---

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

• G4GammaTransition.hh
• G4GammaTransition.cc