| Geant4 Cross Reference |
1 // 1 //
2 // ******************************************* 2 // ********************************************************************
3 // * License and Disclaimer 3 // * License and Disclaimer *
4 // * 4 // * *
5 // * The Geant4 software is copyright of th 5 // * The Geant4 software is copyright of the Copyright Holders of *
6 // * the Geant4 Collaboration. It is provided 6 // * the Geant4 Collaboration. It is provided under the terms and *
7 // * conditions of the Geant4 Software License 7 // * conditions of the Geant4 Software License, included in the file *
8 // * LICENSE and available at http://cern.ch/ 8 // * LICENSE and available at http://cern.ch/geant4/license . These *
9 // * include a list of copyright holders. 9 // * include a list of copyright holders. *
10 // * 10 // * *
11 // * Neither the authors of this software syst 11 // * Neither the authors of this software system, nor their employing *
12 // * institutes,nor the agencies providing fin 12 // * institutes,nor the agencies providing financial support for this *
13 // * work make any representation or warran 13 // * work make any representation or warranty, express or implied, *
14 // * regarding this software system or assum 14 // * regarding this software system or assume any liability for its *
15 // * use. Please see the license in the file 15 // * use. Please see the license in the file LICENSE and URL above *
16 // * for the full disclaimer and the limitatio 16 // * for the full disclaimer and the limitation of liability. *
17 // * 17 // * *
18 // * This code implementation is the result 18 // * This code implementation is the result of the scientific and *
19 // * technical work of the GEANT4 collaboratio 19 // * technical work of the GEANT4 collaboration. *
20 // * By using, copying, modifying or distri 20 // * By using, copying, modifying or distributing the software (or *
21 // * any work based on the software) you ag 21 // * any work based on the software) you agree to acknowledge its *
22 // * use in resulting scientific publicati 22 // * use in resulting scientific publications, and indicate your *
23 // * acceptance of all terms of the Geant4 Sof 23 // * acceptance of all terms of the Geant4 Software license. *
24 // ******************************************* 24 // ********************************************************************
25 // 25 //
>> 26 // $Id: G4DipBustGenerator.cc,v 1.1 2010-10-14 15:17:48 vnivanch Exp $
>> 27 // GEANT4 tag $Name: not supported by cvs2svn $
26 // 28 //
27 // ------------------------------------------- 29 // -------------------------------------------------------------------
28 // 30 //
29 // GEANT4 Class file 31 // GEANT4 Class file
30 // 32 //
31 // 33 //
32 // File name: G4DipBustGenerator 34 // File name: G4DipBustGenerator
33 // 35 //
34 // Author: Vladimir Grichine << 36 // Author: Vladimir Grichine
35 // << 37 //
36 // Creation date: 17 May 2011 38 // Creation date: 17 May 2011
37 // 39 //
38 // Modifications: << 40 // Modifications:
39 // << 41 //
40 // 17.07.2018 optimisations, using G4Pow in S <<
41 // 42 //
42 // Class Description: << 43 // Class Description:
43 // 44 //
44 // Bremsstrahlung Angular Distribution Generat << 45 // Bremsstrahlung Angular Distribution Generation
45 // suggested the dipole approximation in the << 46 // suggested the dipole approximation in the rest frame of electron
46 // busted in the laboratory frame. 47 // busted in the laboratory frame.
47 // 48 //
48 // Class Description: End << 49 // Class Description: End
49 // 50 //
50 // ------------------------------------------- 51 // -------------------------------------------------------------------
51 // 52 //
52 53
53 #include "G4DipBustGenerator.hh" 54 #include "G4DipBustGenerator.hh"
54 #include "Randomize.hh" 55 #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 56
62 G4DipBustGenerator::G4DipBustGenerator(const G 57 G4DipBustGenerator::G4DipBustGenerator(const G4String&)
63 : G4VEmAngularDistribution("DipBustGen") << 58 : G4VBremAngularDistribution("AngularGenUrban")
64 {} << 59 {}
65 60
66 //....oooOO0OOooo........oooOO0OOooo........oo << 61 G4DipBustGenerator::~G4DipBustGenerator()
67 << 62 {}
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 63
88 G4ThreeVector& << 64 G4double G4DipBustGenerator::PolarAngle(const G4double eTkin,
89 G4DipBustGenerator::SampleDirection(const G4Dy << 65 const G4double, // final_energy
90 G4int, co << 66 const G4int ) // Z
91 { 67 {
92 const G4double cosTheta = SampleCosTheta(dp- << 68 G4double c, cosTheta, delta, cofA, signc = 1., a, power = 1./3.;
>> 69 G4double gamma, beta, theta;
93 70
94 const G4double sinTheta = std::sqrt((1. - co << 71 c = 4. - 8.*G4UniformRand();
95 const G4double phi = CLHEP::twopi*G4Uni << 72 a = c;
96 << 73
97 fLocalDirection.set(sinTheta*std::cos(phi), << 74 if( c < 0. )
98 fLocalDirection.rotateUz(dp->GetMomentumDire << 75 {
99 << 76 signc = -1.;
100 return fLocalDirection; << 77 a = -c;
101 } << 78 }
>> 79 delta = std::sqrt(a*a+4.);
>> 80 delta += a;
>> 81 delta *= 0.5;
>> 82
>> 83 cofA = -signc*std::pow(delta, power);
>> 84
>> 85 cosTheta = cofA - 1./cofA;
>> 86
>> 87 gamma = 1. + eTkin/electron_mass_c2;
>> 88 beta = std::sqrt(1. - 1./gamma/gamma);
>> 89
>> 90 cosTheta = (cosTheta + beta)/(1 + cosTheta*beta);
>> 91
>> 92 theta = std::acos(cosTheta);
>> 93
>> 94 if( theta < 0. ) theta = 0.;
>> 95 if( theta > pi ) theta = pi;
>> 96 // G4cout <<"theta = "<<theta<<"; ";
102 97
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; 98 return theta;
113 } 99 }
114 100
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 101 void G4DipBustGenerator::PrintGeneratorInformation() const
144 { 102 {
145 G4cout << "\n" << G4endl; 103 G4cout << "\n" << G4endl;
146 G4cout << "Angular Generator based on classi << 104 G4cout << "Bremsstrahlung Angular Generator is Modified Tsai" << G4endl;
147 G4cout << "J.D. Jackson, Classical Electrody << 105 G4cout << "Distribution suggested by L.Urban (Geant3 manual (1993) Phys211)"
148 << G4endl; 106 << G4endl;
149 } << 107 G4cout << "Derived from Tsai distribution (Rev Mod Phys 49,421(1977)) \n"
150 << 108 << G4endl;
151 //....oooOO0OOooo........oooOO0OOooo........oo << 109 }
152 110