| Geant4 Cross Reference |
1 //
2 // ********************************************************************
3 // * License and Disclaimer *
4 // * *
5 // * The Geant4 software is copyright of the Copyright Holders of *
6 // * the Geant4 Collaboration. It is provided under the terms and *
7 // * conditions of the Geant4 Software License, included in the file *
8 // * LICENSE and available at http://cern.ch/geant4/license . These *
9 // * include a list of copyright holders. *
10 // * *
11 // * Neither the authors of this software system, nor their employing *
12 // * institutes,nor the agencies providing financial support for this *
13 // * work make any representation or warranty, express or implied, *
14 // * regarding this software system or assume any liability for its *
15 // * use. Please see the license in the file LICENSE and URL above *
16 // * for the full disclaimer and the limitation of liability. *
17 // * *
18 // * This code implementation is the result of the scientific and *
19 // * technical work of the GEANT4 collaboration. *
20 // * By using, copying, modifying or distributing the software (or *
21 // * any work based on the software) you agree to acknowledge its *
22 // * use in resulting scientific publications, and indicate your *
23 // * acceptance of all terms of the Geant4 Software license. *
24 // ********************************************************************
25 //
26 //
27 // -------------------------------------------------------------------
28 //
29 // GEANT4 Class file
30 //
31 //
32 // File name: G4DNABornAngle
33 //
34 // Author: Vladimir Ivantcheko
35 //
36 // Creation date: 23 August 2013
37 //
38 // Modifications:
39 //
40 // Class Description:
41 //
42 // Delta-electron Angular Distribution Generation
43 //
44 // Class Description: End
45 //
46 // -------------------------------------------------------------------
47 //
48
49 #include "G4DNABornAngle.hh"
50 #include "G4PhysicalConstants.hh"
51 #include "Randomize.hh"
52 #include "G4ParticleDefinition.hh"
53 #include "G4Electron.hh"
54 #include "G4SystemOfUnits.hh"
55
56 using namespace std;
57
58 G4DNABornAngle::G4DNABornAngle(const G4String&)
59 : G4VEmAngularDistribution("deltaBorn")
60 {
61 fElectron = G4Electron::Electron();
62 }
63
64 G4DNABornAngle::~G4DNABornAngle()
65 = default;
66
67 G4ThreeVector&
68 G4DNABornAngle::SampleDirectionForShell(const G4DynamicParticle* dp,
69 G4double secKinetic, G4int,
70 G4int,
71 const G4Material*)
72 {
73 G4double k = dp->GetKineticEnergy();
74 G4double cosTheta = 1.0;
75
76 if (dp->GetDefinition() == fElectron)
77 {
78 if (secKinetic < 50.*eV) cosTheta = (2.*G4UniformRand())-1.;
79 else if (secKinetic <= 200.*eV)
80 {
81 if (G4UniformRand() <= 0.1) cosTheta = (2.*G4UniformRand())-1.;
82 else cosTheta = G4UniformRand()*(std::sqrt(2.)/2);
83 }
84 else
85 {
86 G4double sin2O =
87 (1.-secKinetic/k)/(1.+secKinetic/(2.*electron_mass_c2));
88 cosTheta = std::sqrt(1.-sin2O);
89 }
90 }
91 else
92 {
93 G4double tau = k/dp->GetDefinition()->GetPDGMass();
94 G4double maxSecKinetic = 2.* electron_mass_c2*tau*(tau + 2.0);
95
96 // Restriction below 100 eV from Emfietzoglou (2000)
97
98 if (secKinetic>100*eV) cosTheta = std::min(std::sqrt(secKinetic / maxSecKinetic), 1.0);
99 else cosTheta = (2.*G4UniformRand())-1.;
100 }
101
102 G4double sint = sqrt((1.0 - cosTheta)*(1.0 + cosTheta));
103 G4double phi = twopi*G4UniformRand();
104
105 fLocalDirection.set(sint*cos(phi), sint*sin(phi), cosTheta);
106 fLocalDirection.rotateUz(dp->GetMomentumDirection());
107
108 return fLocalDirection;
109 }
110
111 G4ThreeVector&
112 G4DNABornAngle::SampleDirection(const G4DynamicParticle* dp,
113 G4double secEkin, G4int Z,
114 const G4Material* mat)
115 {
116 return SampleDirectionForShell(dp, secEkin, Z, 0, mat);
117 }
118
119 void G4DNABornAngle::PrintGeneratorInformation() const
120 {}
121