[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 | // |
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| 27 | // $Id: G4LFission.cc,v 1.15 2007/02/26 19:29:30 dennis Exp $ |
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[1340] | 28 | // GEANT4 tag $Name: geant4-09-03-ref-09 $ |
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[819] | 29 | // |
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| 30 | // |
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| 31 | // G4 Model: Low Energy Fission |
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| 32 | // F.W. Jones, TRIUMF, 03-DEC-96 |
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| 33 | // |
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| 34 | // This is a prototype of a low-energy fission process. |
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| 35 | // Currently it is based on the GHEISHA routine FISSIO, |
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| 36 | // and conforms fairly closely to the original Fortran. |
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| 37 | // Note: energy is in MeV and momentum is in MeV/c. |
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| 38 | // |
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| 39 | // use -scheme for elastic scattering: HPW, 20th June 1997 |
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| 40 | // the code comes mostly from the old Low-energy Fission class |
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| 41 | // |
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| 42 | // 25-JUN-98 FWJ: replaced missing Initialize for ParticleChange. |
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| 43 | // |
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| 44 | |
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| 45 | #include "globals.hh" |
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| 46 | #include "G4LFission.hh" |
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| 47 | #include "Randomize.hh" |
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| 48 | |
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| 49 | G4LFission::G4LFission() : G4HadronicInteraction("G4LFission") |
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| 50 | { |
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| 51 | init(); |
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| 52 | SetMinEnergy( 0.0*GeV ); |
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| 53 | SetMaxEnergy( DBL_MAX ); |
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| 54 | |
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| 55 | } |
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| 56 | |
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| 57 | G4LFission::~G4LFission() |
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| 58 | { |
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| 59 | theParticleChange.Clear(); |
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| 60 | } |
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| 61 | |
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| 62 | |
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| 63 | void |
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| 64 | G4LFission::init() |
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| 65 | { |
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| 66 | G4int i; |
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| 67 | G4double xx = 1. - 0.5; |
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| 68 | G4double xxx = std::sqrt(2.29*xx); |
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| 69 | spneut[0] = std::exp(-xx/0.965)*(std::exp(xxx) - std::exp(-xxx))/2.; |
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| 70 | for (i = 2; i <= 10; i++) { |
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| 71 | xx = i*1. - 0.5; |
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| 72 | xxx = std::sqrt(2.29*xx); |
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| 73 | spneut[i-1] = spneut[i-2] + std::exp(-xx/0.965)*(std::exp(xxx) - std::exp(-xxx))/2.; |
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| 74 | } |
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| 75 | for (i = 1; i <= 10; i++) { |
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| 76 | spneut[i-1] = spneut[i-1]/spneut[9]; |
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| 77 | if (verboseLevel > 1) G4cout << "G4LFission::init: i=" << i << |
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| 78 | " spneut=" << spneut[i-1] << G4endl; |
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| 79 | } |
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| 80 | } |
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| 81 | |
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| 82 | |
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| 83 | G4HadFinalState* |
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| 84 | G4LFission::ApplyYourself(const G4HadProjectile & aTrack,G4Nucleus & targetNucleus) |
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| 85 | { |
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| 86 | theParticleChange.Clear(); |
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| 87 | const G4HadProjectile* aParticle = &aTrack; |
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| 88 | |
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| 89 | G4double N = targetNucleus.GetN(); |
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| 90 | G4double Z = targetNucleus.GetZ(); |
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| 91 | theParticleChange.SetStatusChange(stopAndKill); |
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| 92 | |
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| 93 | G4double P = aParticle->GetTotalMomentum()/MeV; |
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| 94 | G4double Px = aParticle->Get4Momentum().vect().x(); |
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| 95 | G4double Py = aParticle->Get4Momentum().vect().y(); |
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| 96 | G4double Pz = aParticle->Get4Momentum().vect().z(); |
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| 97 | G4double E = aParticle->GetTotalEnergy()/MeV; |
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| 98 | G4double E0 = aParticle->GetDefinition()->GetPDGMass()/MeV; |
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| 99 | G4double Q = aParticle->GetDefinition()->GetPDGCharge(); |
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| 100 | if (verboseLevel > 1) { |
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| 101 | G4cout << "G4LFission:ApplyYourself: incident particle:" << G4endl; |
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| 102 | G4cout << "P " << P << " MeV/c" << G4endl; |
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| 103 | G4cout << "Px " << Px << " MeV/c" << G4endl; |
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| 104 | G4cout << "Py " << Py << " MeV/c" << G4endl; |
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| 105 | G4cout << "Pz " << Pz << " MeV/c" << G4endl; |
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| 106 | G4cout << "E " << E << " MeV" << G4endl; |
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| 107 | G4cout << "mass " << E0 << " MeV" << G4endl; |
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| 108 | G4cout << "charge " << Q << G4endl; |
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| 109 | } |
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| 110 | // GHEISHA ADD operation to get total energy, mass, charge: |
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| 111 | if (verboseLevel > 1) { |
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| 112 | G4cout << "G4LFission:ApplyYourself: material:" << G4endl; |
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| 113 | G4cout << "A " << N << G4endl; |
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| 114 | G4cout << "Z " << Z << G4endl; |
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| 115 | G4cout << "atomic mass " << |
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| 116 | Atomas(N, Z) << "MeV" << G4endl; |
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| 117 | } |
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| 118 | E = E + Atomas(N, Z); |
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| 119 | G4double E02 = E*E - P*P; |
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| 120 | E0 = std::sqrt(std::abs(E02)); |
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| 121 | if (E02 < 0) E0 = -E0; |
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| 122 | Q = Q + Z; |
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| 123 | if (verboseLevel > 1) { |
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| 124 | G4cout << "G4LFission:ApplyYourself: total:" << G4endl; |
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| 125 | G4cout << "E " << E << " MeV" << G4endl; |
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| 126 | G4cout << "mass " << E0 << " MeV" << G4endl; |
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| 127 | G4cout << "charge " << Q << G4endl; |
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| 128 | } |
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| 129 | Px = -Px; |
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| 130 | Py = -Py; |
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| 131 | Pz = -Pz; |
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| 132 | |
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| 133 | G4double e1 = aParticle->GetKineticEnergy()/MeV; |
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| 134 | if (e1 < 1.) e1 = 1.; |
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| 135 | |
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| 136 | // Average number of neutrons |
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| 137 | G4double avern = 2.569 + 0.559*std::log(e1); |
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| 138 | G4bool photofission = 0; // For now |
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| 139 | // Take the following value if photofission is not included |
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| 140 | if (!photofission) avern = 2.569 + 0.900*std::log(e1); |
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| 141 | |
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| 142 | // Average number of gammas |
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| 143 | G4double averg = 9.500 + 0.600*std::log(e1); |
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| 144 | |
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| 145 | G4double ran = G4RandGauss::shoot(); |
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| 146 | // Number of neutrons |
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| 147 | G4int nn = static_cast<G4int>(avern + ran*1.23 + 0.5); |
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| 148 | ran = G4RandGauss::shoot(); |
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| 149 | // Number of gammas |
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| 150 | G4int ng = static_cast<G4int>(averg + ran*3. + 0.5); |
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| 151 | if (nn < 1) nn = 1; |
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| 152 | if (ng < 1) ng = 1; |
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| 153 | G4double exn = 0.; |
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| 154 | G4double exg = 0.; |
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| 155 | |
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| 156 | // Make secondary neutrons and distribute kinetic energy |
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| 157 | G4DynamicParticle* aNeutron; |
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| 158 | G4int i; |
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| 159 | for (i = 1; i <= nn; i++) { |
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| 160 | ran = G4UniformRand(); |
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| 161 | G4int j; |
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| 162 | for (j = 1; j <= 10; j++) { |
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| 163 | if (ran < spneut[j-1]) goto label12; |
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| 164 | } |
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| 165 | j = 10; |
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| 166 | label12: |
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| 167 | ran = G4UniformRand(); |
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| 168 | G4double ekin = (j - 1)*1. + ran; |
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| 169 | exn = exn + ekin; |
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| 170 | aNeutron = new G4DynamicParticle(G4Neutron::NeutronDefinition(), |
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| 171 | G4ParticleMomentum(1.,0.,0.), |
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| 172 | ekin*MeV); |
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| 173 | theParticleChange.AddSecondary(aNeutron); |
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| 174 | } |
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| 175 | |
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| 176 | // Make secondary gammas and distribute kinetic energy |
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| 177 | G4DynamicParticle* aGamma; |
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| 178 | for (i = 1; i <= ng; i++) { |
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| 179 | ran = G4UniformRand(); |
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| 180 | G4double ekin = -0.87*std::log(ran); |
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| 181 | exg = exg + ekin; |
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| 182 | aGamma = new G4DynamicParticle(G4Gamma::GammaDefinition(), |
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| 183 | G4ParticleMomentum(1.,0.,0.), |
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| 184 | ekin*MeV); |
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| 185 | theParticleChange.AddSecondary(aGamma); |
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| 186 | } |
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| 187 | |
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| 188 | // Distribute momentum vectors and do Lorentz transformation |
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| 189 | |
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| 190 | G4HadSecondary* theSecondary; |
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| 191 | |
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| 192 | for (i = 1; i <= nn + ng; i++) { |
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| 193 | G4double ran1 = G4UniformRand(); |
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| 194 | G4double ran2 = G4UniformRand(); |
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| 195 | G4double cost = -1. + 2.*ran1; |
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| 196 | G4double sint = std::sqrt(std::abs(1. - cost*cost)); |
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| 197 | G4double phi = ran2*twopi; |
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| 198 | // G4cout << ran1 << " " << ran2 << G4endl; |
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| 199 | // G4cout << cost << " " << sint << " " << phi << G4endl; |
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| 200 | theSecondary = theParticleChange.GetSecondary(i - 1); |
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| 201 | G4double pp = theSecondary->GetParticle()->GetTotalMomentum()/MeV; |
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| 202 | G4double px = pp*sint*std::sin(phi); |
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| 203 | G4double py = pp*sint*std::cos(phi); |
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| 204 | G4double pz = pp*cost; |
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| 205 | // G4cout << pp << G4endl; |
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| 206 | // G4cout << px << " " << py << " " << pz << G4endl; |
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| 207 | G4double e = theSecondary->GetParticle()->GetTotalEnergy()/MeV; |
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| 208 | G4double e0 = theSecondary->GetParticle()->GetDefinition()->GetPDGMass()/MeV; |
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| 209 | |
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| 210 | G4double a = px*Px + py*Py + pz*Pz; |
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| 211 | a = (a/(E + E0) - e)/E0; |
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| 212 | |
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| 213 | px = px + a*Px; |
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| 214 | py = py + a*Py; |
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| 215 | pz = pz + a*Pz; |
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| 216 | G4double p2 = px*px + py*py + pz*pz; |
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| 217 | pp = std::sqrt(p2); |
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| 218 | e = std::sqrt(e0*e0 + p2); |
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| 219 | G4double ekin = e - theSecondary->GetParticle()->GetDefinition()->GetPDGMass()/MeV; |
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| 220 | theSecondary->GetParticle()->SetMomentumDirection(G4ParticleMomentum(px/pp, |
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| 221 | py/pp, |
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| 222 | pz/pp)); |
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| 223 | theSecondary->GetParticle()->SetKineticEnergy(ekin*MeV); |
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| 224 | } |
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| 225 | |
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| 226 | return &theParticleChange; |
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| 227 | } |
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| 228 | |
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| 229 | // Computes atomic mass in MeV (translation of GHEISHA routine ATOMAS) |
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| 230 | // Not optimized: conforms closely to original Fortran. |
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| 231 | |
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| 232 | G4double |
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| 233 | G4LFission::Atomas(const G4double A, const G4double Z) |
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| 234 | { |
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| 235 | G4double rmel = G4Electron::ElectronDefinition()->GetPDGMass()/MeV; |
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| 236 | G4double rmp = G4Proton::ProtonDefinition()->GetPDGMass()/MeV; |
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| 237 | G4double rmn = G4Neutron::NeutronDefinition()->GetPDGMass()/MeV; |
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| 238 | G4double rmd = G4Deuteron::DeuteronDefinition()->GetPDGMass()/MeV; |
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| 239 | G4double rma = G4Alpha::AlphaDefinition()->GetPDGMass()/MeV; |
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| 240 | |
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| 241 | G4int ia = static_cast<G4int>(A + 0.5); |
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| 242 | if (ia < 1) return 0; |
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| 243 | G4int iz = static_cast<G4int>(Z + 0.5); |
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| 244 | if (iz < 0) return 0; |
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| 245 | if (iz > ia) return 0; |
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| 246 | |
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| 247 | if (ia == 1) { |
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| 248 | if (iz == 0) return rmn; //neutron |
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| 249 | if (iz == 1) return rmp + rmel; //Hydrogen |
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| 250 | } |
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| 251 | else if (ia == 2 && iz == 1) { |
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| 252 | return rmd; //Deuteron |
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| 253 | } |
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| 254 | else if (ia == 4 && iz == 2) { |
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| 255 | return rma; //Alpha |
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| 256 | } |
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| 257 | |
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| 258 | G4double mass = (A - Z)*rmn + Z*rmp + Z*rmel |
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| 259 | - 15.67*A |
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| 260 | + 17.23*std::pow(A, 2./3.) |
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| 261 | + 93.15*(A/2. - Z)*(A/2. - Z)/A |
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| 262 | + 0.6984523*Z*Z/std::pow(A, 1./3.); |
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| 263 | G4int ipp = (ia - iz)%2; |
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| 264 | G4int izz = iz%2; |
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| 265 | if (ipp == izz) mass = mass + (ipp + izz -1)*12.*std::pow(A, -0.5); |
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| 266 | |
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| 267 | return mass; |
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| 268 | } |
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