[819] | 1 | // |
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| 2 | // ******************************************************************** |
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| 3 | // * License and Disclaimer * |
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| 4 | // * * |
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| 5 | // * The Geant4 software is copyright of the Copyright Holders of * |
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| 6 | // * the Geant4 Collaboration. It is provided under the terms and * |
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| 7 | // * conditions of the Geant4 Software License, included in the file * |
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| 8 | // * LICENSE and available at http://cern.ch/geant4/license . These * |
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| 9 | // * include a list of copyright holders. * |
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| 10 | // * * |
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| 11 | // * Neither the authors of this software system, nor their employing * |
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| 12 | // * institutes,nor the agencies providing financial support for this * |
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| 13 | // * work make any representation or warranty, express or implied, * |
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| 14 | // * regarding this software system or assume any liability for its * |
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| 15 | // * use. Please see the license in the file LICENSE and URL above * |
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| 16 | // * for the full disclaimer and the limitation of liability. * |
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| 17 | // * * |
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| 18 | // * This code implementation is the result of the scientific and * |
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| 19 | // * technical work of the GEANT4 collaboration. * |
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| 20 | // * By using, copying, modifying or distributing the software (or * |
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| 21 | // * any work based on the software) you agree to acknowledge its * |
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| 22 | // * use in resulting scientific publications, and indicate your * |
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| 23 | // * acceptance of all terms of the Geant4 Software license. * |
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| 24 | // ******************************************************************** |
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| 25 | // |
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| 26 | // $Id: G4VPolarizedCrossSection.cc,v 1.4 2007/11/01 17:32:34 schaelic Exp $ |
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| 27 | // GEANT4 tag $Name: $ |
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| 28 | // File name: G4VPolarizedCrossSection |
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| 29 | // |
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| 30 | // Author: Andreas Schaelicke |
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| 31 | // |
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| 32 | // Creation date: 15.05.2005 |
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| 33 | // |
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| 34 | // Modifications: |
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| 35 | // |
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| 36 | // Class Description: |
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| 37 | // (pure virtual) interface class |
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| 38 | // |
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| 39 | // provides readable but efficient routines to determine |
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| 40 | // polarization for the final state of a given process |
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| 41 | // empoying the differential cross section |
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| 42 | // |
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| 43 | |
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| 44 | #include "G4VPolarizedCrossSection.hh" |
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| 45 | #include "Randomize.hh" |
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| 46 | |
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| 47 | G4VPolarizedCrossSection::G4VPolarizedCrossSection() : |
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| 48 | fXmin(0), fXmax(1.), fYmin(1.), theA(1), theZ(1), fCoul(0.) |
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| 49 | { |
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| 50 | } |
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| 51 | |
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| 52 | G4VPolarizedCrossSection::~G4VPolarizedCrossSection() |
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| 53 | { |
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| 54 | } |
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| 55 | |
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| 56 | void G4VPolarizedCrossSection::Initialize(G4double, G4double, G4double, |
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| 57 | const G4StokesVector &, |
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| 58 | const G4StokesVector &, |
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| 59 | G4int ) |
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| 60 | { |
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| 61 | } |
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| 62 | |
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| 63 | G4StokesVector G4VPolarizedCrossSection::GetPol2() |
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| 64 | { |
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| 65 | // neglects correlation effects! |
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| 66 | |
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| 67 | G4double invXsecTotal=1./XSection(G4StokesVector::ZERO,G4StokesVector::ZERO); |
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| 68 | G4double xsPol1=XSection(G4StokesVector::P1,G4StokesVector::ZERO); |
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| 69 | G4double xsPol2=XSection(G4StokesVector::P2,G4StokesVector::ZERO); |
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| 70 | G4double xsPol3=XSection(G4StokesVector::P3,G4StokesVector::ZERO); |
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| 71 | return G4ThreeVector(invXsecTotal*xsPol1,invXsecTotal*xsPol2,invXsecTotal*xsPol3); |
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| 72 | } |
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| 73 | |
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| 74 | G4StokesVector G4VPolarizedCrossSection::GetPol3() |
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| 75 | { |
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| 76 | // neglects correlation effects! |
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| 77 | |
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| 78 | G4double invXsecTotal=1./XSection(G4StokesVector::ZERO,G4StokesVector::ZERO); |
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| 79 | G4double xsPol1=XSection(G4StokesVector::ZERO,G4StokesVector::P1); |
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| 80 | G4double xsPol2=XSection(G4StokesVector::ZERO,G4StokesVector::P2); |
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| 81 | G4double xsPol3=XSection(G4StokesVector::ZERO,G4StokesVector::P3); |
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| 82 | return G4ThreeVector(invXsecTotal*xsPol1,invXsecTotal*xsPol2,invXsecTotal*xsPol3); |
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| 83 | } |
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| 84 | // minimal energy fraction in TotalXSection |
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| 85 | G4double G4VPolarizedCrossSection::GetXmin(G4double /*y*/) |
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| 86 | { |
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| 87 | return fXmin; |
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| 88 | } |
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| 89 | |
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| 90 | // maximal energy fraction in TotalXSection |
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| 91 | G4double G4VPolarizedCrossSection::GetXmax(G4double /*y*/) |
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| 92 | { |
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| 93 | return fXmax; |
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| 94 | } |
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| 95 | |
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| 96 | |
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| 97 | /* |
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| 98 | void G4VPolarizedCrossSection::DicePolarization() |
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| 99 | { |
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| 100 | // can respect correlation effects, but is limited to |
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| 101 | // one quantization axis! |
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| 102 | G4double sigma[4]; |
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| 103 | sigma[0]=XSection(G4StokesVector::P3,G4StokesVector::P3); |
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| 104 | sigma[1]=XSection(G4StokesVector::P3,G4StokesVector::M3); |
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| 105 | sigma[2]=XSection(G4StokesVector::M3,G4StokesVector::P3); |
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| 106 | sigma[3]=XSection(G4StokesVector::M3,G4StokesVector::M3); |
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| 107 | |
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| 108 | G4double sigma_max = 4. * XSection(G4StokesVector::ZERO,G4StokesVector::ZERO); |
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| 109 | |
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| 110 | for (G4int i=0;i<4;++i) { |
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| 111 | G4cout<<"sigma="<<sigma[i]<<" vs."<<(.25*sigma_max)<<G4endl; |
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| 112 | if (sigma[i]<0 || sigma[i]>sigma_max) { |
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| 113 | G4cout<<"ERROR G4VPolarizedCrossSection::DicePolarization(["<<i<<"]): " |
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| 114 | <<sigma[i]<<" vs."<<sigma_max<<G4endl; |
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| 115 | } |
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| 116 | if (i>0) sigma[i]+=sigma[i-1]; |
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| 117 | } |
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| 118 | |
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| 119 | G4int k = 0; |
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| 120 | G4double disc = sigma[3]*G4UniformRand(); |
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| 121 | while (sigma[k]<disc && k<4) { |
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| 122 | ++k; |
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| 123 | } |
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| 124 | |
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| 125 | if ((k&2)==0) pol2=G4StokesVector::P3; |
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| 126 | else pol2=G4StokesVector::M3; |
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| 127 | if ((k&1)==0) pol3=G4StokesVector::P3; |
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| 128 | else pol3=G4StokesVector::M3; |
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| 129 | |
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| 130 | } |
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| 131 | */ |
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| 132 | |
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| 133 | /* |
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| 134 | G4StokesVector G4VPolarizedCrossSection::DicedPol2() |
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| 135 | { |
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| 136 | return pol2; |
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| 137 | } |
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| 138 | |
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| 139 | G4StokesVector G4VPolarizedCrossSection::DicedPol3() |
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| 140 | { |
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| 141 | return pol3; |
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| 142 | } |
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| 143 | */ |
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| 144 | |
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| 145 | G4double G4VPolarizedCrossSection::TotalXSection(const G4double, const G4double, const G4double, |
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| 146 | const G4StokesVector &,const G4StokesVector &) |
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| 147 | { |
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| 148 | G4cout << "WARNING virtual function G4VPolarizedCrossSection::TotalXSection() called" << G4endl; |
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| 149 | return 0.; |
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| 150 | } |
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