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1 // 1 2 // ******************************************* 3 // * License and Disclaimer 4 // * 5 // * The Geant4 software is copyright of th 6 // * the Geant4 Collaboration. It is provided 7 // * conditions of the Geant4 Software License 8 // * LICENSE and available at http://cern.ch/ 9 // * include a list of copyright holders. 10 // * 11 // * Neither the authors of this software syst 12 // * institutes,nor the agencies providing fin 13 // * work make any representation or warran 14 // * regarding this software system or assum 15 // * use. Please see the license in the file 16 // * for the full disclaimer and the limitatio 17 // * 18 // * This code implementation is the result 19 // * technical work of the GEANT4 collaboratio 20 // * By using, copying, modifying or distri 21 // * any work based on the software) you ag 22 // * use in resulting scientific publicati 23 // * acceptance of all terms of the Geant4 Sof 24 // ******************************************* 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