include/Geant4/G4eplusTo2or3GammaModel.hh

0001 //
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0025 //
0026 //
0027 // -------------------------------------------------------------------
0028 //
0029 // GEANT4 Class header file
0030 //
0031 //
0032 // File name:     G4eplusTo2or3GammaModel
0033 //
0034 // Author:        Vladimir Ivanchenko and Omrane Kadri
0035 //
0036 // Creation date: 29.03.2018
0037 //
0038 //
0039 // Class Description:
0040 //
0041 // Implementation of e+ annihilation into 2 or 3 gamma on fly
0042 // Annihilation at rest is sampled by G4VPositronAtRestModel
0043 // Implementation of 3-gamma annihilation is performed by
0044 // G4eplusTo3GammaOKVIModel. Cross section of both models
0045 // depend on cut parameter fDelta, which defines relative low-energy
0046 // limit on 3d gamma energy. For computation of the cross section
0047 // next to leading order radiative corrections are taken into account,
0048 // atomic effects at low-energy are not considered.
0049 //
0050 // V.N.Baier, V.S. Fadin, V.A. Khose, E.A. Kuraev,
0051 // Physics Reports 78 (1981) 293-393.
0052 //
0053 // -------------------------------------------------------------------
0054 //
0055
0056 #ifndef G4eplusTo2or3GammaModel_h
0057 #define G4eplusTo2or3GammaModel_h 1
0058
0059 #include "G4VEmModel.hh"
0060
0061 class G4eplusTo3GammaOKVIModel;
0062 class G4ParticleChangeForGamma;
0063 class G4PhysicsVector;
0064 class G4DataVector;
0065
0066 class G4eplusTo2or3GammaModel : public G4VEmModel
0067 {
0068
0069 public:
0070
0071   G4eplusTo2or3GammaModel();
0072
0073   ~G4eplusTo2or3GammaModel() override;
0074
0075   void Initialise(const G4ParticleDefinition*, const G4DataVector&) override;
0076
0077   G4double ComputeCrossSectionPerElectron(G4double kinEnergy);
0078
0079   G4double ComputeCrossSectionPerAtom(
0080                                  const G4ParticleDefinition*,
0081                                  G4double kinEnergy,
0082                                  G4double Z,
0083                                  G4double A = 0.,
0084                                  G4double cutEnergy = 0.,
0085                                  G4double maxEnergy = DBL_MAX) override;
0086
0087   G4double CrossSectionPerVolume(const G4Material*,
0088                  const G4ParticleDefinition*,
0089                  G4double kineticEnergy,
0090                  G4double cutEnergy = 0.0,
0091                  G4double maxEnergy = DBL_MAX) override;
0092
0093   void SampleSecondaries(std::vector<G4DynamicParticle*>*,
0094                  const G4MaterialCutsCouple*,
0095                  const G4DynamicParticle*,
0096                  G4double tmin = 0.0,
0097                  G4double maxEnergy = DBL_MAX) override;
0098
0099   void SetDelta(G4double val) { if(val > 0.0) { fDeltaMin = val; } };
0100
0101   // hide assignment operator
0102   G4eplusTo2or3GammaModel & operator=
0103   (const  G4eplusTo2or3GammaModel &right) = delete;
0104   G4eplusTo2or3GammaModel(const  G4eplusTo2or3GammaModel&) = delete;
0105
0106 private:
0107
0108   const G4ParticleDefinition* theGamma;
0109   G4ParticleChangeForGamma* fParticleChange;
0110   G4eplusTo3GammaOKVIModel* f3GModel;
0111
0112   G4double fDeltaMin; // fixed minimal relative limit
0113   G4double fDelta;    // running limit - function of energy
0114   G4double fGammaTh;  // 3-gamma annihilation low-energy limit
0115
0116   static G4PhysicsVector* fCrossSection;
0117   static G4PhysicsVector* f3GProbability;
0118 };
0119
0120 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0121
0122 #endif