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25 //
26 //
27 // -------------------------------------------
28 //
29 // GEANT4 Class file
30 //
31 //
32 // File name: G4DipBustGenerator
33 //
34 // Author: Vladimir Grichine
35 //
36 // Creation date: 17 May 2011
37 //
38 // Modifications:
39 //
40 // 17.07.2018 optimisations, using G4Pow in S
41 //
42 // Class Description:
43 //
44 // Bremsstrahlung Angular Distribution Generat
45 // suggested the dipole approximation in the
46 // busted in the laboratory frame.
47 //
48 // Class Description: End
49 //
50 // -------------------------------------------
51 //
52
53 #include "G4DipBustGenerator.hh"
54 #include "Randomize.hh"
55 // #include "G4Log.hh"
56 // #include "G4Exp.hh"
57 #include "G4Pow.hh"
58 #include <CLHEP/Units/PhysicalConstants.h>
59
60 //....oooOO0OOooo........oooOO0OOooo........oo
61
62 G4DipBustGenerator::G4DipBustGenerator(const G
63 : G4VEmAngularDistribution("DipBustGen")
64 {}
65
66 //....oooOO0OOooo........oooOO0OOooo........oo
67
68 G4DipBustGenerator::~G4DipBustGenerator() = de
69
70 //....oooOO0OOooo........oooOO0OOooo........oo
71
72 G4double G4DipBustGenerator::SampleCosTheta(co
73 {
74 const G4double c = 4. - 8.*G4UniformR
75 const G4double delta = 0.5*(std::sqrt(c*c
76 const G4double signc = (c < 0.) ? -1.0 :
77 // const G4double cofA = -signc*G4Exp(G4Log(
78 const G4double cofA = -signc*G4Pow::GetI
79 const G4double cosTheta = std::min(1.,std::m
80 const G4double tau = kinEnergy/CLHEP::e
81 const G4double beta = std::sqrt(tau*(tau
82
83 return (cosTheta + beta)/(1. + cosTheta*beta
84 }
85
86 //....oooOO0OOooo........oooOO0OOooo........oo
87
88 G4ThreeVector&
89 G4DipBustGenerator::SampleDirection(const G4Dy
90 G4int, co
91 {
92 const G4double cosTheta = SampleCosTheta(dp-
93
94 const G4double sinTheta = std::sqrt((1. - co
95 const G4double phi = CLHEP::twopi*G4Uni
96
97 fLocalDirection.set(sinTheta*std::cos(phi),
98 fLocalDirection.rotateUz(dp->GetMomentumDire
99
100 return fLocalDirection;
101 }
102
103 //....oooOO0OOooo........oooOO0OOooo........oo
104
105 G4double G4DipBustGenerator::PolarAngle(G4doub
106 G4dou
107 G4int
108 {
109 const G4double cosTheta = SampleCosTheta(eTk
110 G4double theta = std::acos(cosTheta);
111 theta = std::min(std::max(theta, 0.), CLHEP:
112 return theta;
113 }
114
115 //....oooOO0OOooo........oooOO0OOooo........oo
116
117 void G4DipBustGenerator::SamplePairDirections(
118
119
120
121
122
123 {
124 const G4double phi = CLHEP::twopi * G4Unifo
125 const G4double sinp = std::sin(phi);
126 const G4double cosp = std::cos(phi);
127
128 G4double cost = SampleCosTheta(elecKinEnergy
129 G4double sint = std::sqrt((1. - cost)*(1. +
130
131 dirElectron.set(sint*cosp, sint*sinp, cost);
132 dirElectron.rotateUz(dp->GetMomentumDirectio
133
134 cost = SampleCosTheta(posiKinEnergy);
135 sint = std::sqrt((1. - cost)*(1. + cost));
136
137 dirPositron.set(-sint*cosp, -sint*sinp, cost
138 dirPositron.rotateUz(dp->GetMomentumDirectio
139 }
140
141 //....oooOO0OOooo........oooOO0OOooo........oo
142
143 void G4DipBustGenerator::PrintGeneratorInforma
144 {
145 G4cout << "\n" << G4endl;
146 G4cout << "Angular Generator based on classi
147 G4cout << "J.D. Jackson, Classical Electrody
148 << G4endl;
149 }
150
151 //....oooOO0OOooo........oooOO0OOooo........oo
152