| 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 // Geant4 Class file << 26 // $Id: G4PolarizationHelper.cc,v 1.4.4.2 2010/01/26 16:36:05 gcosmo Exp $
>> 27 // GEANT4 tag $Name: geant4-09-02-patch-03 $
>> 28 //
>> 29 // GEANT4 Class file
>> 30 //
27 // 31 //
28 // File name: G4PolarizationHelper 32 // File name: G4PolarizationHelper
29 // 33 //
30 // Author: Andreas Schaelicke 34 // Author: Andreas Schaelicke
31 // 35 //
>> 36 // Creation date: 12.08.2006
>> 37 //
>> 38 // Modifications:
>> 39 //
32 // Class Description: 40 // Class Description:
33 // Provides some basic polarization transfor << 41 //
34 << 42 // Provides some basic polarization transformation routines.
>> 43 //
35 #include "G4PolarizationHelper.hh" 44 #include "G4PolarizationHelper.hh"
36 <<
37 #include "G4PhysicalConstants.hh" <<
38 #include "G4StokesVector.hh" 45 #include "G4StokesVector.hh"
39 #include "Randomize.hh" <<
40 46
41 G4ThreeVector G4PolarizationHelper::GetFrame(c << 47
42 c << 48 G4ThreeVector G4PolarizationHelper::GetFrame(const G4ThreeVector & mom1, const G4ThreeVector & mom2)
43 { 49 {
44 G4ThreeVector normal = (mom1.cross(mom2)).un << 50 G4ThreeVector normal = mom1.cross(mom2);
45 return normal; << 51 return 1./normal.mag()*normal;
46 } 52 }
47 53
48 G4ThreeVector G4PolarizationHelper::GetParticl << 54 G4ThreeVector G4PolarizationHelper::GetParticleFrameY(const G4ThreeVector &uZ)
49 { 55 {
50 if(uZ.x() == 0. && uZ.y() == 0.) << 56 // compare also G4ThreeVector::rotateUz()
51 { << 57
52 return G4ThreeVector(0., 1., 0.); << 58 if (uZ.x()==0. && uZ.y()==0.) {
>> 59 return G4ThreeVector(0.,1.,0.);
53 } 60 }
54 61
55 G4double invPerp = 1. / std::sqrt(sqr(uZ.x() << 62 G4double invPerp = 1./std::sqrt(sqr(uZ.x())+sqr(uZ.y()));
56 return G4ThreeVector(-uZ.y() * invPerp, uZ.x << 63 return G4ThreeVector(-uZ.y()*invPerp,uZ.x()*invPerp,0);
57 } 64 }
58 65
59 G4ThreeVector G4PolarizationHelper::GetParticl << 66 G4ThreeVector G4PolarizationHelper::GetParticleFrameX(const G4ThreeVector &uZ)
60 { 67 {
61 if(uZ.x() == 0. && uZ.y() == 0.) << 68 // compare also G4ThreeVector::rotateUz()
62 { << 69
63 if(uZ.z() >= 0.) << 70 if (uZ.x()==0. && uZ.y()==0.) {
64 return G4ThreeVector(1., 0., 0.); << 71 if (uZ.z()>=0.) return G4ThreeVector(1.,0.,0.);
65 return G4ThreeVector(-1., 0., 0.); << 72 return G4ThreeVector(-1.,0.,0.);
66 } 73 }
67 74
68 G4double perp = std::sqrt(sqr(uZ.x()) + s << 75 G4double perp = std::sqrt(sqr(uZ.x())+sqr(uZ.y()));
69 G4double invPerp = uZ.z() / perp; << 76 G4double invPerp = uZ.z()/perp;
70 return G4ThreeVector(uZ.x() * invPerp, uZ.y( << 77 return G4ThreeVector(uZ.x()*invPerp,uZ.y()*invPerp,-perp);
71 } 78 }
72 79
73 G4ThreeVector G4PolarizationHelper::GetRandomF << 80 G4ThreeVector G4PolarizationHelper::GetRandomFrame(const G4ThreeVector & mom1)
74 { 81 {
75 G4double phi = 2. * pi * G4UniformRand(); << 82 G4double phi =2.*pi*G4UniformRand();
76 G4ThreeVector normal = << 83 G4ThreeVector normal = std::cos(phi)*GetParticleFrameX(mom1)
77 std::cos(phi) * GetParticleFrameX(mom1) + << 84 + std::sin(phi)*G4PolarizationHelper::GetParticleFrameY(mom1);
78 std::sin(phi) * G4PolarizationHelper::GetP <<
79 return normal; 85 return normal;
80 } 86 }
81 87
82 G4ThreeVector G4PolarizationHelper::GetSpinInP << 88
83 << 89 G4ThreeVector G4PolarizationHelper::GetSpinInPRF(const G4ThreeVector &uZ, const G4ThreeVector & spin)
84 { 90 {
85 if(uZ.x() == 0. && uZ.y() == 0.) << 91 // compare also G4ThreeVector::rotateUz()
86 { <<
87 if(uZ.z() >= 0.) <<
88 return spin; <<
89 return G4ThreeVector(-spin.x(), spin.y(), <<
90 } <<
91 92
92 G4double perp = std::sqrt(sqr(uZ.x()) + s << 93 if (uZ.x()==0. && uZ.y()==0.) {
93 G4double invPerp = 1. / perp; << 94 if (uZ.z()>=0.) return spin;
>> 95 return G4ThreeVector(-spin.x(),spin.y(),-spin.z());
>> 96 }
94 97
95 G4ThreeVector uX(uZ.x() * uZ.z() * invPerp, << 98 G4double perp = std::sqrt(sqr(uZ.x())+sqr(uZ.y()));
96 G4ThreeVector uY(-uZ.y() * invPerp, uZ.x() * << 99 G4double invPerp = uZ.z()/perp;
97 100
98 return G4ThreeVector(spin * uX, spin * uY, s << 101 G4ThreeVector uX(uZ.x()*invPerp,uZ.y()*invPerp,-perp);
>> 102 G4ThreeVector uY(-uZ.y()*invPerp,uZ.x()*invPerp,0);
>> 103
>> 104 return G4ThreeVector(spin*uX,spin*uY,spin*uZ);
99 } 105 }
100 106
101 void G4PolarizationHelper::TestPolarizationTra 107 void G4PolarizationHelper::TestPolarizationTransformations()
102 { 108 {
103 G4double theta = 0.; << 109 G4double theta=0.;
104 G4cout << "================================= << 110 G4cout<<"========================================\n\n";
105 for(G4int i = 0; i <= 10; ++i) << 111 for (G4int i=0; i<=10; ++i) {
106 { << 112 theta=pi*i/10.;
107 theta = pi * i / 10.; << 113 G4ThreeVector zAxis = G4ThreeVector(std::sin(theta),0.,std::cos(theta));
108 G4ThreeVector zAxis = G4ThreeVector(std::s << 114 if (i==5) zAxis = G4ThreeVector(1.,0.,0.);
109 if(i == 5) << 115 if (i==10) zAxis = G4ThreeVector(0.,0.,-1.);
110 zAxis = G4ThreeVector(1., 0., 0.); <<
111 if(i == 10) <<
112 zAxis = G4ThreeVector(0., 0., -1.); <<
113 G4ThreeVector yAxis = GetParticleFrameY(zA 116 G4ThreeVector yAxis = GetParticleFrameY(zAxis);
114 117
115 G4cout << zAxis << " " << zAxis.mag() << " << 118 G4cout<<zAxis<<" "<<zAxis.mag()<<"\n";
116 G4cout << yAxis << " " << yAxis.mag() << " << 119 G4cout<<yAxis<<" "<<yAxis.mag()<<"\n";
117 G4ThreeVector xAxis = yAxis.cross(zAxis); 120 G4ThreeVector xAxis = yAxis.cross(zAxis);
118 G4cout << xAxis << " " << xAxis.mag() << " << 121 G4cout<<xAxis<<" "<<xAxis.mag()<<"\n\n";
119 } 122 }
120 123
121 G4cout << "================================= << 124 G4cout<<"========================================\n\n";
122 125
123 for(G4int i = 0; i <= 10; ++i) << 126 for (G4int i=0; i<=10; ++i) {
124 { << 127 theta=pi*i/10.;
125 theta = pi * i / 10.; << 128 G4ThreeVector zAxis = G4ThreeVector(0.,std::sin(theta),std::cos(theta));
126 G4ThreeVector zAxis = G4ThreeVector(0., st << 129 if (i==5) zAxis = G4ThreeVector(0.,1.,0.);
127 if(i == 5) << 130 if (i==10) zAxis = G4ThreeVector(0.,0.,-1.);
128 zAxis = G4ThreeVector(0., 1., 0.); <<
129 if(i == 10) <<
130 zAxis = G4ThreeVector(0., 0., -1.); <<
131 G4ThreeVector yAxis = GetParticleFrameY(zA 131 G4ThreeVector yAxis = GetParticleFrameY(zAxis);
132 132
133 G4cout << zAxis << " " << zAxis.mag() << " << 133 G4cout<<zAxis<<" "<<zAxis.mag()<<"\n";
134 G4cout << yAxis << " " << yAxis.mag() << " << 134 G4cout<<yAxis<<" "<<yAxis.mag()<<"\n";
135 G4ThreeVector xAxis = yAxis.cross(zAxis); 135 G4ThreeVector xAxis = yAxis.cross(zAxis);
136 G4cout << xAxis << " " << xAxis.mag() << " << 136 G4cout<<xAxis<<" "<<xAxis.mag()<<"\n\n";
137 <<
138 G4cout << "spat : " << xAxis * yAxis.cross <<
139 } 137 }
140 G4cout << "================================= << 138 G4cout<<"========================================\n\n";
141 } 139 }
142 140
143 void G4PolarizationHelper::TestInteractionFram 141 void G4PolarizationHelper::TestInteractionFrame()
144 { 142 {
145 // check transformation procedure for polari << 143 // check transformation procedure for polarisation transfer
146 // calculation in scattering processes 144 // calculation in scattering processes
147 // a) transfer target polarisation in beam 145 // a) transfer target polarisation in beam particle reference frame (PRF)
148 // b) calc correct asymmetry w.r.t. scatter 146 // b) calc correct asymmetry w.r.t. scattering plane
149 // c) determine incoming polarisation in in << 147 // c) determine incomming polarisation in interaction frame (IF)
150 // d) transfer outgoing polarisation from I 148 // d) transfer outgoing polarisation from IF to PRF
151 G4cout << "================================= << 149 G4cout<<"========================================\n\n";
152 <<
153 G4double theta = 0.; <<
154 150
155 G4ThreeVector dir0 = G4ThreeVector(0., 0., 1 << 151 G4double theta=0.;
156 G4ThreeVector dir2 = G4ThreeVector(std::sin( <<
157 152
158 G4StokesVector pol0 = G4StokesVector::P3; << 153 G4ThreeVector dir0=G4ThreeVector(0.,0.,1.);
159 G4StokesVector pol1 = G4StokesVector::P3; << 154 G4ThreeVector dir2=G4ThreeVector(std::sin(theta),0.,std::cos(theta));
>> 155
>> 156 G4StokesVector pol0=G4ThreeVector(0.,0.,1.);
>> 157 G4StokesVector pol1=G4ThreeVector(0.,0.,1.);
160 158
161 pol1.rotateUz(dir0); 159 pol1.rotateUz(dir0);
162 160
163 G4cout << "================================= << 161 G4cout<<"========================================\n\n";
>> 162
>> 163
164 } 164 }
165 165