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25 //
26 // Geant4 Class file
27 //
28 // File name: G4PolarizedPhotoElectricXS
29 //
30 // Author: Karim Laihem
31
32 #include "G4PolarizedPhotoElectricXS.hh"
33
34 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
35 G4PolarizedPhotoElectricXS::G4PolarizedPhotoElectricXS()
36 {
37 fFinalElectronPolarization = G4StokesVector::ZERO;
38 }
39
40 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
41 G4PolarizedPhotoElectricXS::~G4PolarizedPhotoElectricXS() {}
42
43 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
44 void G4PolarizedPhotoElectricXS::Initialize(G4double aGammaE, G4double aLept0E,
45 G4double sinTheta,
46 const G4StokesVector& beamPol,
47 const G4StokesVector& /*p1*/,
48 G4int /*flag*/)
49 {
50 // Polarization transfer to e- in PhotoelectricEffect.
51 G4double Gfactor = aLept0E / CLHEP::electron_mass_c2 + 1.;
52 G4double Gfactor_2 = Gfactor * Gfactor;
53
54 G4double beta = std::sqrt(1. - 1. / (Gfactor_2));
55
56 G4double Stokes_P3 = beamPol.z();
57
58 G4double Lept0E = aLept0E / CLHEP::electron_mass_c2 + 1.;
59 G4double Lept0E2 = Lept0E * Lept0E;
60 G4double GammaE = aGammaE / CLHEP::electron_mass_c2;
61
62 G4double cosTheta = std::sqrt(1. - sinTheta * sinTheta);
63
64 G4double I_Lepton0 =
65 1.0 +
66 (1. / GammaE) * ((2. / (GammaE * Lept0E * (1 - beta * cosTheta))) - 1.);
67
68 G4double A_Lepton0 =
69 (Lept0E / (Lept0E + 1)) *
70 (2.0 / (GammaE * Lept0E) + beta * cosTheta +
71 (2.0 / ((GammaE * Lept0E2) * (1.0 - beta * cosTheta)))) /
72 I_Lepton0;
73
74 G4double B_Lepton0 = (Lept0E / (Lept0E + 1.0)) * beta * sinTheta *
75 (2.0 / (GammaE * Lept0E * (1 - beta * cosTheta)) - 1.0) /
76 I_Lepton0;
77
78 fFinalElectronPolarization.setX(Stokes_P3 * B_Lepton0);
79 fFinalElectronPolarization.setY(0.);
80 fFinalElectronPolarization.setZ(Stokes_P3 * A_Lepton0);
81
82 if((fFinalElectronPolarization.x() * fFinalElectronPolarization.x() +
83 fFinalElectronPolarization.y() * fFinalElectronPolarization.y() +
84 fFinalElectronPolarization.z() * fFinalElectronPolarization.z()) > 1.)
85
86 {
87 G4ExceptionDescription ed;
88 ed << "Warning: PhotoelectricEffect Problem in pol-transfer photon to "
89 "lepton:Px2 + Py2 + Pz2 > 1\n";
90 ed << "Polarization transfer forced to be total and similar as incoming "
91 "Photo\n";
92 G4Exception("G4PolarizedPhotoElectricXS::Initialize", "pol023", JustWarning,
93 ed);
94 fFinalElectronPolarization = beamPol; // to be safe
95 }
96 }
97
98 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
99 G4double G4PolarizedPhotoElectricXS::XSection(const G4StokesVector& /*pol2*/,
100 const G4StokesVector& /*pol3*/)
101 {
102 G4ExceptionDescription ed;
103 ed << "ERROR dummy routine G4PolarizedPhotoElectricXS::XSection() "
104 "called\n";
105 G4Exception("G4PolarizedPhotoElectricXS::XSection", "pol024", FatalException,
106 ed);
107 return 0.;
108 }
109
110 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
111 G4StokesVector G4PolarizedPhotoElectricXS::GetPol2()
112 {
113 return fFinalElectronPolarization;
114 }
115
116 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
117 G4StokesVector G4PolarizedPhotoElectricXS::GetPol3()
118 {
119 return G4StokesVector();
120 }
121