1 | // |
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2 | // ******************************************************************** |
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3 | // * License and Disclaimer * |
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6 | // * the Geant4 Collaboration. It is provided under the terms and * |
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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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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 | // |
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27 | // $Id: G4NeutronHPNBodyPhaseSpace.cc,v 1.13 2006/06/29 20:53:11 gunter Exp $ |
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28 | // GEANT4 tag $Name: $ |
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29 | // |
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30 | #include "G4NeutronHPNBodyPhaseSpace.hh" |
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31 | #include "G4Gamma.hh" |
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32 | #include "G4Electron.hh" |
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33 | #include "G4Positron.hh" |
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34 | #include "G4Neutron.hh" |
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35 | #include "G4Proton.hh" |
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36 | #include "G4Deuteron.hh" |
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37 | #include "G4Triton.hh" |
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38 | #include "G4He3.hh" |
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39 | #include "G4Alpha.hh" |
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40 | #include "Randomize.hh" |
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41 | #include "G4ThreeVector.hh" |
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42 | |
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43 | G4ReactionProduct * G4NeutronHPNBodyPhaseSpace::Sample(G4double anEnergy, G4double massCode, G4double ) |
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44 | { |
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45 | G4ReactionProduct * result = new G4ReactionProduct; |
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46 | G4int Z = static_cast<G4int>(massCode/1000); |
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47 | G4int A = static_cast<G4int>(massCode-1000*Z); |
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48 | |
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49 | if(massCode==0) |
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50 | { |
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51 | result->SetDefinition(G4Gamma::Gamma()); |
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52 | } |
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53 | else if(A==0) |
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54 | { |
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55 | result->SetDefinition(G4Electron::Electron()); |
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56 | if(Z==1) result->SetDefinition(G4Positron::Positron()); |
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57 | } |
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58 | else if(A==1) |
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59 | { |
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60 | result->SetDefinition(G4Neutron::Neutron()); |
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61 | if(Z==1) result->SetDefinition(G4Proton::Proton()); |
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62 | } |
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63 | else if(A==2) |
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64 | { |
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65 | result->SetDefinition(G4Deuteron::Deuteron()); |
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66 | } |
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67 | else if(A==3) |
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68 | { |
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69 | result->SetDefinition(G4Triton::Triton()); |
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70 | if(Z==2) result->SetDefinition(G4He3::He3()); |
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71 | } |
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72 | else if(A==4) |
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73 | { |
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74 | result->SetDefinition(G4Alpha::Alpha()); |
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75 | if(Z!=2) throw G4HadronicException(__FILE__, __LINE__, "Unknown ion case 1"); |
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76 | } |
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77 | else |
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78 | { |
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79 | throw G4HadronicException(__FILE__, __LINE__, "G4NeutronHPNBodyPhaseSpace: Unknown ion case 2"); |
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80 | } |
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81 | |
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82 | // Get the energy from phase-space distribution |
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83 | // in CMS |
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84 | // P = Cn*std::sqrt(E')*(Emax-E')**(3*n/2-4) |
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85 | G4double maxE = GetEmax(anEnergy, result->GetMass()); |
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86 | G4double energy; |
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87 | G4double max(0); |
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88 | if(theTotalCount<=3) |
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89 | { |
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90 | max = maxE/2.; |
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91 | } |
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92 | else if(theTotalCount==4) |
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93 | { |
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94 | max = maxE/5.; |
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95 | } |
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96 | else if(theTotalCount==5) |
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97 | { |
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98 | max = maxE/8.; |
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99 | } |
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100 | else |
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101 | { |
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102 | throw G4HadronicException(__FILE__, __LINE__, "NeutronHP Phase-space distribution cannot cope with this number of particles"); |
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103 | } |
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104 | G4double testit; |
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105 | G4double rand0 = Prob(max, maxE, theTotalCount); |
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106 | G4double rand; |
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107 | |
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108 | do |
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109 | { |
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110 | rand = rand0*G4UniformRand(); |
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111 | energy = maxE*G4UniformRand(); |
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112 | testit = Prob(energy, maxE, theTotalCount); |
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113 | } |
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114 | while(rand > testit); |
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115 | result->SetKineticEnergy(energy); |
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116 | |
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117 | // now do random direction |
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118 | G4double cosTh = 2.*G4UniformRand()-1.; |
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119 | G4double phi = twopi*G4UniformRand(); |
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120 | G4double theta = std::acos(cosTh); |
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121 | G4double sinth = std::sin(theta); |
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122 | G4double mtot = result->GetTotalMomentum(); |
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123 | G4ThreeVector tempVector(mtot*sinth*std::cos(phi), mtot*sinth*std::sin(phi), mtot*std::cos(theta) ); |
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124 | result->SetMomentum(tempVector); |
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125 | G4ReactionProduct aCMS = *GetTarget()+*GetNeutron(); |
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126 | result->Lorentz(*result, -1.*aCMS); |
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127 | return result; |
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128 | } |
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