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27 //
28 // ------------ G4AnnihiToMuPair physics process ------
29 // by H.Burkhardt, S. Kelner and R. Kokoulin, November 2002
30 // -----------------------------------------------------------------------------
31
32 // class description
33 //
34 // (high energy) e+ (atomic) e- ---> mu+ mu-
35 // inherit from G4VDiscreteProcess
36 //
37 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......//
38 //
39 // 04.02.03 : cosmetic simplifications (mma)
40 // 27.01.03 : first implementation (hbu)
41 //
42 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
43
44 #ifndef G4AnnihiToMuPair_h
45 #define G4AnnihiToMuPair_h 1
46
47 #include "G4VDiscreteProcess.hh"
48 #include "globals.hh"
49
50 class G4LossTableManager;
51 class G4ParticleDefinition;
52 class G4Track;
53 class G4Step;
54
55 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
56
57 class G4AnnihiToMuPair : public G4VDiscreteProcess
58 {
59 public: // with description
60
61 explicit G4AnnihiToMuPair(const G4String& processName ="AnnihiToMuPair",
62 G4ProcessType type = fElectromagnetic);
63
64 ~G4AnnihiToMuPair() override;
65
66 G4bool IsApplicable(const G4ParticleDefinition&) override;
67 // true for positron only.
68
69 void BuildPhysicsTable(const G4ParticleDefinition&) override;
70 // here dummy, just calling PrintInfoDefinition
71 // the total cross section is calculated analytically
72
73 void PrintInfoDefinition();
74 // Print few lines of informations about the process: validity range,
75 // origine ..etc..
76 // Invoked by BuildPhysicsTable().
77
78 void SetCrossSecFactor(G4double fac);
79 // Set the factor to artificially increase the crossSection (default 1)
80
81 G4double GetCrossSecFactor() {return fCrossSecFactor;};
82 // Get the factor to artificially increase the cross section
83
84 G4double CrossSectionPerVolume(G4double positronEnergy, const G4Material*);
85
86 G4double ComputeCrossSectionPerElectron(const G4double energy);
87
88 G4double ComputeCrossSectionPerAtom(const G4double energy, const G4double Z);
89
90 G4double GetMeanFreePath(const G4Track& aTrack,
91 G4double previousStepSize,
92 G4ForceCondition* ) override;
93 // It returns the MeanFreePath of the process for the current track :
94 // (energy, material)
95 // The previousStepSize and G4ForceCondition* are not used.
96 // This function overloads a virtual function of the base class.
97 // It is invoked by the ProcessManager of the Particle.
98
99 G4VParticleChange* PostStepDoIt(const G4Track& aTrack,
100 const G4Step& aStep) override;
101 // It computes the final state of the process (at end of step),
102 // returned as a ParticleChange object.
103 // This function overloads a virtual function of the base class.
104 // It is invoked by the ProcessManager of the Particle.
105
106 // hide assignment operator as private
107 G4AnnihiToMuPair& operator=(const G4AnnihiToMuPair &right) = delete;
108 G4AnnihiToMuPair(const G4AnnihiToMuPair& ) = delete;
109
110 private:
111
112 G4LossTableManager* fManager;
113 const G4ParticleDefinition* part1;
114 const G4ParticleDefinition* part2;
115 G4double fMass;
116
117 G4double fLowEnergyLimit; // Energy threshold of e+
118 G4double fHighEnergyLimit; // Limit of validity of the model
119 G4double fCurrentSigma; // the last value of cross section per volume
120 G4double fCrossSecFactor; // factor to increase the cross section
121 G4String fInfo = "e+e->mu+mu-";
122 };
123
124 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
125
126 #endif
127
128