source: trunk/source/processes/electromagnetic/polarisation/src/G4PolarizedBremsstrahlungCrossSection.cc@ 1199

Last change on this file since 1199 was 1196, checked in by garnier, 16 years ago

update CVS release candidate geant4.9.3.01
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25//
26// $Id: G4PolarizedBremsstrahlungCrossSection.cc,v 1.4 2007/11/01 17:32:34 schaelic Exp $
27// GEANT4 tag $Name: geant4-09-03-cand-01 $
28//
29// -------------------------------------------------------------------
30//
31// GEANT4 Class file
32//
33//
34// File name: G4PolarizedBremsstrahlungCrossSection
35//
36// Author: Andreas Schaelicke on the base of Karim Laihems code
37//
38// Creation date: 16.08.2006
39//
40
41#include "G4PolarizedBremsstrahlungCrossSection.hh"
42//#include "G4ePolarizedBremsstrahlungModel.hh"
43//#include "G4Element.hh"
44
45G4bool G4PolarizedBremsstrahlungCrossSection::scrnInitialized=false;
46G4double G4PolarizedBremsstrahlungCrossSection::SCRN [3][20];
47// screening function lookup table;
48
49
50void G4PolarizedBremsstrahlungCrossSection::InitializeMe()
51{
52 if (!scrnInitialized) {
53 SCRN [1][1]= 0.5 ; SCRN [2][1] = 0.0145;
54 SCRN [1][2]= 1.0 ; SCRN [2][2] = 0.0490;
55 SCRN [1][3]= 2.0 ; SCRN [2][3] = 0.1400;
56 SCRN [1][4]= 4.0 ; SCRN [2][4] = 0.3312;
57 SCRN [1][5]= 8.0 ; SCRN [2][5] = 0.6758;
58 SCRN [1][6]= 15.0 ; SCRN [2][6] = 1.126;
59 SCRN [1][7]= 20.0 ; SCRN [2][7] = 1.367;
60 SCRN [1][8]= 25.0 ; SCRN [2][8] = 1.564;
61 SCRN [1][9]= 30.0 ; SCRN [2][9] = 1.731;
62 SCRN [1][10]= 35.0 ; SCRN [2][10]= 1.875;
63 SCRN [1][11]= 40.0 ; SCRN [2][11]= 2.001;
64 SCRN [1][12]= 45.0 ; SCRN [2][12]= 2.114;
65 SCRN [1][13]= 50.0 ; SCRN [2][13]= 2.216;
66 SCRN [1][14]= 60.0 ; SCRN [2][14]= 2.393;
67 SCRN [1][15]= 70.0 ; SCRN [2][15]= 2.545;
68 SCRN [1][16]= 80.0 ; SCRN [2][16]= 2.676;
69 SCRN [1][17]= 90.0 ; SCRN [2][17]= 2.793;
70 SCRN [1][18]= 100.0 ; SCRN [2][18]= 2.897;
71 SCRN [1][19]= 120.0 ; SCRN [2][19]= 3.078;
72
73 scrnInitialized=true;
74 }
75}
76
77G4PolarizedBremsstrahlungCrossSection::G4PolarizedBremsstrahlungCrossSection()
78{
79 InitializeMe();
80}
81
82
83void G4PolarizedBremsstrahlungCrossSection::Initialize(
84 G4double aLept0E, G4double aGammaE, G4double sintheta,
85 const G4StokesVector & beamPol,
86 const G4StokesVector & /*p1*/,
87 G4int /*flag*/)
88{
89// G4cout<<"G4PolarizedBremsstrahlungCrossSection::Initialize \n"
90// <<"lepE = "<<aLept0E
91// <<"gamE = "<<aGammaE
92// <<"sint = "<<sintheta<<"\n"
93// <<"beamPol="<<beamPol<<"\n";
94
95 G4double aLept1E = aLept0E - aGammaE;
96
97 G4double Stokes_S1 = beamPol.x() ;
98 G4double Stokes_S2 = beamPol.y() ;
99 G4double Stokes_S3 = beamPol.z() ;
100 // **************************************************************************
101
102 G4double m0_c2 = electron_mass_c2;
103 G4double Lept0E = aLept0E/m0_c2+1., Lept0E2 = Lept0E * Lept0E ;
104 G4double GammaE = aGammaE/m0_c2, GammaE2 = GammaE * GammaE ;
105 G4double Lept1E = aLept1E/m0_c2+1., Lept1E2 = Lept1E * Lept1E ;
106
107
108 // const G4Element* theSelectedElement = theModel->SelectedAtom();
109
110 // ******* Gamma Transvers Momentum
111
112 G4double TMom = std::sqrt(Lept0E2 -1.)* sintheta;
113 G4double u = TMom , u2 =u * u ;
114 G4double Xsi = 1./(1.+u2) , Xsi2 = Xsi * Xsi ;
115
116 // G4double theZ = theSelectedElement->GetZ();
117
118 // G4double fCoul = theSelectedElement->GetfCoulomb();
119 G4double delta = 12. * std::pow(theZ, 1./3.) *
120 Lept0E * Lept1E * Xsi / (121. * GammaE);
121 G4double GG=0.;
122
123 if(delta < 0.5) {
124 GG = std::log(2.* Lept0E * Lept1E / GammaE) - 2. - fCoul;
125 }
126 else if ( delta < 120) {
127 for (G4int j=2; j<=19; j++) {
128 if(SCRN[1][j] >= delta) {
129 GG =std::log(2 * Lept0E * Lept1E / GammaE) - 2 - fCoul
130 -(SCRN[2][j-1]+(delta-SCRN[1][j-1])*(SCRN[2][j]-SCRN[2][j-1])
131 /(SCRN[1][j]-SCRN[1][j-1]));
132 break;
133 }
134 }
135 }
136 else {
137 G4double alpha_sc = (111 * std::pow(theZ, -1./3.)) / Xsi;
138 GG = std::log(alpha_sc)- 2 - fCoul;
139 }
140
141 if(GG<-1) GG=-1; // *KL* do we need this ?!
142
143 G4double I_Lept = (Lept0E2 + Lept1E2) * (3.+2.*GG) - 2 * Lept0E * Lept1E * (1. + 4. * u2 * Xsi2 * GG);
144 G4double F_Lept = Lept1E * 4. * GammaE * u * Xsi * (1. - 2 * Xsi) * GG / I_Lept;
145 G4double E_Lept = Lept0E * 4. * GammaE * u * Xsi * (2. * Xsi - 1.) * GG / I_Lept;
146 G4double M_Lept = 4. * Lept0E * Lept1E * (1. + GG - 2. * Xsi2 * u2 * GG) / I_Lept ;
147 G4double P_Lept = GammaE2 * (1. + 8. * GG * (Xsi - 0.5)*(Xsi - 0.5)) / I_Lept ;
148
149 G4double Stokes_SS1 = M_Lept * Stokes_S1 + E_Lept * Stokes_S3;
150 G4double Stokes_SS2 = M_Lept * Stokes_S2 ;
151 G4double Stokes_SS3 = (M_Lept + P_Lept) * Stokes_S3 + F_Lept * Stokes_S1;
152
153 theFinalLeptonPolarization.setX(Stokes_SS1);
154 theFinalLeptonPolarization.setY(Stokes_SS2);
155 theFinalLeptonPolarization.setZ(Stokes_SS3);
156
157 if(theFinalLeptonPolarization.mag2()>1) {
158 G4cout<<" WARNING in pol-brem theFinalLeptonPolarization \n";
159 G4cout
160 <<"\t"<<theFinalLeptonPolarization
161 <<"\t GG\t"<<GG
162 <<"\t delta\t"<<delta
163 <<G4endl;
164 theFinalLeptonPolarization.setX(0);
165 theFinalLeptonPolarization.setY(0);
166 theFinalLeptonPolarization.setZ(Stokes_SS3);
167 if(Stokes_SS3>1) theFinalLeptonPolarization.setZ(1);
168 }
169
170
171 G4double I_Gamma = (Lept0E2 + Lept1E2)*(3+2*GG) - 2 * Lept0E * Lept1E * (1 + 4 * u2 * Xsi2 * GG);
172 G4double D_Gamma = 8 * Lept0E * Lept1E * u2 * Xsi2 * GG / I_Gamma;
173 G4double L_Gamma = GammaE * ((Lept0E + Lept1E) * (3 + 2 * GG)
174 - 2 * Lept1E * (1 + 4 * u2 * Xsi2 * GG))/I_Gamma;
175 G4double T_Gamma = 4 * GammaE * Lept1E * Xsi * u * (2 * Xsi - 1) * GG / I_Gamma ;
176
177 G4double Stokes_P1 = D_Gamma ;
178 G4double Stokes_P2 = 0 ;
179 G4double Stokes_P3 = (Stokes_S3*L_Gamma + Stokes_S1*T_Gamma) ;
180
181 theFinalGammaPolarization.SetPhoton();
182
183 theFinalGammaPolarization.setX(Stokes_P1);
184 theFinalGammaPolarization.setY(Stokes_P2);
185 theFinalGammaPolarization.setZ(Stokes_P3);
186
187 if(theFinalGammaPolarization.mag2()>1) {
188 G4cout<<" WARNING in pol-brem theFinalGammaPolarization \n";
189 G4cout
190 <<"\t"<<theFinalGammaPolarization
191 <<"\t GG\t"<<GG
192 <<"\t delta\t"<<delta
193 <<G4endl;
194 }
195}
196
197G4double G4PolarizedBremsstrahlungCrossSection::XSection(const G4StokesVector & /*pol2*/,
198 const G4StokesVector & /*pol3*/)
199{
200 G4cout<<"ERROR dummy routine G4PolarizedBremsstrahlungCrossSection::XSection called \n";
201 return 0;
202}
203
204 // return expected mean polarisation
205G4StokesVector G4PolarizedBremsstrahlungCrossSection::GetPol2()
206{
207 // electron/positron
208 return theFinalLeptonPolarization;
209}
210G4StokesVector G4PolarizedBremsstrahlungCrossSection::GetPol3()
211{
212 // photon
213 return theFinalGammaPolarization;;
214}
215
216
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