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 | #include "G4AngularDistributionNP.hh" |
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27 | #include "Randomize.hh" |
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28 | #include "G4ios.hh" |
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29 | |
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30 | // Initialization of static data arrays: |
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31 | #include "G4AngularDistributionNPData.hh" |
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32 | #include "Randomize.hh" |
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33 | |
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34 | |
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35 | G4double G4AngularDistributionNP::CosTheta(G4double s, G4double m1, G4double m2) const |
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36 | { |
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37 | G4int verboseLevel=1; |
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38 | |
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39 | G4double ek= ((s - sqr(m1) -sqr(m2) )/(2*m1) - m1 )/GeV ; // kinetic energy in GeV |
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40 | |
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41 | // Find energy bin |
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42 | |
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43 | G4int je1 = 0; |
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44 | G4int je2 = NENERGY - 1; |
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45 | do { |
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46 | G4int midBin = (je1 + je2)/2; |
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47 | if (ek < elab[midBin]) |
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48 | je2 = midBin; |
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49 | else |
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50 | je1 = midBin; |
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51 | } while (je2 - je1 > 1); |
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52 | // G4int j; |
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53 | //std::abs(ek-elab[je1]) < std::abs(ek-elab[je2]) ? j = je1 : j = je2; |
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54 | G4double delab = elab[je2] - elab[je1]; |
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55 | |
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56 | // Sample the angle |
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57 | |
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58 | G4float sample = G4UniformRand(); |
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59 | G4int ke1 = 0; |
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60 | G4int ke2 = NANGLE - 1; |
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61 | G4double dsig = sig[je2][0] - sig[je1][0]; |
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62 | G4double rc = dsig/delab; |
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63 | G4double b = sig[je1][0] - rc*elab[je1]; |
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64 | G4double sigint1 = rc*ek + b; |
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65 | G4double sigint2 = 0.; |
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66 | |
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67 | if (verboseLevel > 1) G4cout << "sample=" << sample << G4endl |
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68 | << ek << " " << ke1 << " " << ke2 << " " |
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69 | << sigint1 << " " << sigint2 << G4endl; |
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70 | |
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71 | do { |
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72 | G4int midBin = (ke1 + ke2)/2; |
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73 | dsig = sig[je2][midBin] - sig[je1][midBin]; |
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74 | rc = dsig/delab; |
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75 | b = sig[je1][midBin] - rc*elab[je1]; |
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76 | G4double sigint = rc*ek + b; |
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77 | if (sample < sigint) { |
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78 | ke2 = midBin; |
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79 | sigint2 = sigint; |
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80 | } |
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81 | else { |
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82 | ke1 = midBin; |
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83 | sigint1 = sigint; |
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84 | } |
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85 | if (verboseLevel > 1)G4cout << ke1 << " " << ke2 << " " |
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86 | << sigint1 << " " << sigint2 << G4endl; |
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87 | } while (ke2 - ke1 > 1); |
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88 | |
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89 | // sigint1 and sigint2 should be recoverable from above loop |
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90 | |
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91 | // G4double dsig = sig[je2][ke1] - sig[je1][ke1]; |
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92 | // G4double rc = dsig/delab; |
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93 | // G4double b = sig[je1][ke1] - rc*elab[je1]; |
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94 | // G4double sigint1 = rc*ek + b; |
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95 | |
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96 | // G4double dsig = sig[je2][ke2] - sig[je1][ke2]; |
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97 | // G4double rc = dsig/delab; |
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98 | // G4double b = sig[je1][ke2] - rc*elab[je1]; |
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99 | // G4double sigint2 = rc*ek + b; |
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100 | |
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101 | dsig = sigint2 - sigint1; |
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102 | rc = 1./dsig; |
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103 | b = ke1 - rc*sigint1; |
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104 | G4double kint = rc*sample + b; |
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105 | G4double theta = (0.5 + kint)*pi/180.; |
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106 | |
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107 | // G4int k; |
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108 | //std::abs(sample-sig[j][ke1]) < std::abs(sample-sig[j][ke2]) ? k = ke1 : k = ke2; |
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109 | // G4double theta = (0.5 + k)*pi/180.; |
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110 | |
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111 | if (verboseLevel > 1) { |
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112 | G4cout << " energy bin " << je1 << " energy=" << elab[je1] << G4endl; |
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113 | G4cout << " angle bin " << kint << " angle=" << theta/degree << G4endl; |
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114 | } |
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115 | G4double costh= std::cos(theta); |
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116 | return costh; |
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117 | } |
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118 | |
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119 | G4double G4AngularDistributionNP::Phi() const |
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120 | { |
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121 | return twopi * G4UniformRand(); |
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122 | } |
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