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27 // ------------------------------------------- 27 // -------------------------------------------------------------------
28 // 28 //
29 // GEANT4 Class file 29 // GEANT4 Class file
30 // 30 //
31 // 31 //
32 // File name: G4ModifiedMephi 32 // File name: G4ModifiedMephi
33 // 33 //
34 // Author: V. Ivanchenko 34 // Author: V. Ivanchenko
35 // 35 //
36 // Creation date: 27 October 2020 36 // Creation date: 27 October 2020
37 // 37 //
38 // Modifications: 38 // Modifications:
39 // 39 //
40 // 40 //
41 // ------------------------------------------- 41 // -------------------------------------------------------------------
42 // 42 //
43 43
44 #include "G4ModifiedMephi.hh" 44 #include "G4ModifiedMephi.hh"
45 #include "Randomize.hh" 45 #include "Randomize.hh"
46 #include "G4Log.hh" 46 #include "G4Log.hh"
47 #include <CLHEP/Units/PhysicalConstants.h> 47 #include <CLHEP/Units/PhysicalConstants.h>
48 48
49 //....oooOO0OOooo........oooOO0OOooo........oo 49 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
50 50
51 G4ModifiedMephi::G4ModifiedMephi(const G4Strin 51 G4ModifiedMephi::G4ModifiedMephi(const G4String&)
52 : G4VEmAngularDistribution("ModifiedMephi") 52 : G4VEmAngularDistribution("ModifiedMephi")
53 {} 53 {}
54 54
55 //....oooOO0OOooo........oooOO0OOooo........oo 55 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
56 56
57 G4ModifiedMephi::~G4ModifiedMephi() 57 G4ModifiedMephi::~G4ModifiedMephi()
58 {} 58 {}
59 59
60 //....oooOO0OOooo........oooOO0OOooo........oo 60 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
61 61
62 G4ThreeVector& 62 G4ThreeVector&
63 G4ModifiedMephi::SampleDirection(const G4Dynam 63 G4ModifiedMephi::SampleDirection(const G4DynamicParticle* dp,
64 G4double gEne 64 G4double gEnergy, G4int,
65 const G4Mater 65 const G4Material*)
66 { 66 {
67 // Sample gamma angle (Z - axis along the pa 67 // Sample gamma angle (Z - axis along the parent particle).
68 G4double cost = SampleCosTheta(dp->GetKineti 68 G4double cost = SampleCosTheta(dp->GetKineticEnergy(), gEnergy,
69 dp->GetDefini 69 dp->GetDefinition()->GetPDGMass());
70 G4double sint = std::sqrt((1.0 - cost)*(1.0 70 G4double sint = std::sqrt((1.0 - cost)*(1.0 + cost));
71 G4double phi = CLHEP::twopi*G4UniformRand() 71 G4double phi = CLHEP::twopi*G4UniformRand();
72 72
73 fLocalDirection.set(sint*std::cos(phi), sint 73 fLocalDirection.set(sint*std::cos(phi), sint*std::sin(phi), cost);
74 fLocalDirection.rotateUz(dp->GetMomentumDire 74 fLocalDirection.rotateUz(dp->GetMomentumDirection());
75 75
76 return fLocalDirection; 76 return fLocalDirection;
77 } 77 }
78 78
79 //....oooOO0OOooo........oooOO0OOooo........oo 79 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
80 80
81 G4double G4ModifiedMephi::SampleCosTheta(G4dou 81 G4double G4ModifiedMephi::SampleCosTheta(G4double primKinEnergy,
82 G4dou 82 G4double gEnergy,
83 G4dou 83 G4double mass)
84 { 84 {
85 G4double gam = 1.0 + primKinEnergy/mass; 85 G4double gam = 1.0 + primKinEnergy/mass;
86 G4double rmax = gam*CLHEP::halfpi*std::min(1 86 G4double rmax = gam*CLHEP::halfpi*std::min(1.0, gam*mass/gEnergy - 1.0);
87 G4double rmax2= rmax*rmax; 87 G4double rmax2= rmax*rmax;
88 G4double x = G4UniformRand()*rmax2/(1.0 + rm 88 G4double x = G4UniformRand()*rmax2/(1.0 + rmax2);
89 89
90 return std::cos(std::sqrt(x/(1.0 - x))/gam); 90 return std::cos(std::sqrt(x/(1.0 - x))/gam);
91 } 91 }
92 92
93 //....oooOO0OOooo........oooOO0OOooo........oo 93 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
94 94
95 void G4ModifiedMephi::SamplePairDirections(con 95 void G4ModifiedMephi::SamplePairDirections(const G4DynamicParticle* dp,
96 G4double elecKinEnergy, 96 G4double elecKinEnergy,
97 G4double posiKinEnergy, 97 G4double posiKinEnergy,
98 G4ThreeVector& dirElectron, 98 G4ThreeVector& dirElectron,
99 G4ThreeVector& dirPositron, 99 G4ThreeVector& dirPositron,
100 G4int, const G4Material*) 100 G4int, const G4Material*)
101 { 101 {
102 G4double phi = CLHEP::twopi * G4UniformRand 102 G4double phi = CLHEP::twopi * G4UniformRand();
103 G4double sinp = std::sin(phi); 103 G4double sinp = std::sin(phi);
104 G4double cosp = std::cos(phi); 104 G4double cosp = std::cos(phi);
105 105
106 G4double ekin = dp->GetKineticEnergy(); 106 G4double ekin = dp->GetKineticEnergy();
107 G4double etwo = elecKinEnergy + posiKinEnerg 107 G4double etwo = elecKinEnergy + posiKinEnergy;
108 G4double mass = dp->GetDefinition()->GetPDGM 108 G4double mass = dp->GetDefinition()->GetPDGMass();
109 109
110 G4double cost = SampleCosTheta(ekin, etwo, m 110 G4double cost = SampleCosTheta(ekin, etwo, mass);
111 G4double sint = std::sqrt((1.0 - cost)*(1.0 111 G4double sint = std::sqrt((1.0 - cost)*(1.0 + cost));
112 112
113 dirElectron.set(sint*cosp, sint*sinp, cost); 113 dirElectron.set(sint*cosp, sint*sinp, cost);
114 dirElectron.rotateUz(dp->GetMomentumDirectio 114 dirElectron.rotateUz(dp->GetMomentumDirection());
115 115
116 cost = SampleCosTheta(ekin, etwo, mass); 116 cost = SampleCosTheta(ekin, etwo, mass);
117 sint = std::sqrt((1.0 - cost)*(1.0 + cost)); 117 sint = std::sqrt((1.0 - cost)*(1.0 + cost));
118 118
119 dirPositron.set(-sint*cosp, -sint*sinp, cost 119 dirPositron.set(-sint*cosp, -sint*sinp, cost);
120 dirPositron.rotateUz(dp->GetMomentumDirectio 120 dirPositron.rotateUz(dp->GetMomentumDirection());
121 } 121 }
122 122
123 //....oooOO0OOooo........oooOO0OOooo........oo 123 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
124 124
125 void G4ModifiedMephi::PrintGeneratorInformatio 125 void G4ModifiedMephi::PrintGeneratorInformation() const
126 { 126 {
127 G4cout << "\n" << G4endl; 127 G4cout << "\n" << G4endl;
128 G4cout << "Angular Generator is Modified Mep 128 G4cout << "Angular Generator is Modified Mephi" << G4endl;
129 } 129 }
130 130
131 //....oooOO0OOooo........oooOO0OOooo........oo 131 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
132 132