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25 //
26 //
27 // -------------------------------------------------------------------
28 //
29 // GEANT4 Class file
30 //
31 //
32 // File name: G4DNARuddAngle
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 "G4DNARuddAngle.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 G4DNARuddAngle::G4DNARuddAngle(const G4String&)
59 : G4VEmAngularDistribution("deltaRudd")
60 {
61 fElectron = G4Electron::Electron();
62 }
63
64 G4DNARuddAngle::~G4DNARuddAngle()
65 = default;
66
67 G4ThreeVector&
68 G4DNARuddAngle::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 const G4ParticleDefinition* particle = dp->GetDefinition();
77 G4double mass = particle->GetPDGMass();
78
79 G4double maximumEnergyTransfer = k;
80 if(particle == fElectron) { maximumEnergyTransfer *= 0.5; }
81 else if(mass > MeV) {
82 G4double ratio = electron_mass_c2/mass;
83 G4double tau = k/mass;
84 maximumEnergyTransfer = 2.0*electron_mass_c2*tau*(tau + 2.) /
85 (1. + 2.0*(tau + 1.)*ratio + ratio*ratio);
86
87 }
88
89 if (secKinetic>100*eV && secKinetic <= maximumEnergyTransfer) {
90 cosTheta = std::sqrt(secKinetic / maximumEnergyTransfer);
91 } else {
92 cosTheta = (2.*G4UniformRand())-1.;
93 }
94
95 G4double sint = sqrt((1.0 - cosTheta)*(1.0 + cosTheta));
96 G4double phi = twopi*G4UniformRand();
97
98 fLocalDirection.set(sint*cos(phi), sint*sin(phi), cosTheta);
99 fLocalDirection.rotateUz(dp->GetMomentumDirection());
100
101 return fLocalDirection;
102 }
103
104 G4ThreeVector&
105 G4DNARuddAngle::SampleDirection(const G4DynamicParticle* dp,
106 G4double secEkin, G4int Z,
107 const G4Material* mat)
108 {
109 return SampleDirectionForShell(dp, secEkin, Z, 0, mat);
110 }
111
112 void G4DNARuddAngle::PrintGeneratorInformation() const
113 {}
114