[1350] | 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 | // G4IonCoulombScatteringModel.cc |
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| 27 | // ------------------------------------------------------------------- |
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| 28 | // |
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| 29 | // GEANT4 Class header file |
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| 30 | // |
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| 31 | // File name: G4IonCoulombScatteringModel |
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| 32 | // |
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| 33 | // Author: Cristina Consolandi |
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| 34 | // |
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| 35 | // Creation date: 05.10.2010 from G4eCoulombScatteringModel |
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| 36 | // & G4CoulombScatteringModel |
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| 37 | // |
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| 38 | // Class Description: |
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| 39 | // Single Scattering Model for |
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| 40 | // for protons, alpha and heavy Ions |
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| 41 | // |
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| 42 | // Reference: |
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| 43 | // M.J. Boschini et al. "Nuclear and Non-Ionizing Energy-Loss |
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| 44 | // for Coulomb ScatteredParticles from Low Energy up to Relativistic |
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| 45 | // Regime in Space Radiation Environment" |
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| 46 | // Accepted for publication in the Proceedings of the ICATPP Conference |
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| 47 | // on Cosmic Rays for Particle and Astroparticle Physics, Villa Olmo, 7-8 |
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| 48 | // October, 2010, to be published by World Scientific (Singapore). |
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| 49 | // |
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| 50 | // Available for downloading at: |
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| 51 | // http://arxiv.org/abs/1011.4822 |
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| 52 | // |
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| 53 | // ------------------------------------------------------------------- |
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| 54 | // |
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| 55 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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| 56 | |
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| 57 | |
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| 58 | #include "G4IonCoulombScatteringModel.hh" |
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| 59 | #include "Randomize.hh" |
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| 60 | //#include "G4DataVector.hh" |
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| 61 | #include "G4ParticleChangeForGamma.hh" |
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| 62 | #include "G4Proton.hh" |
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| 63 | #include "G4ProductionCutsTable.hh" |
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| 64 | #include "G4NucleiProperties.hh" |
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| 65 | |
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| 66 | #include "G4UnitsTable.hh" |
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| 67 | |
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| 68 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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| 69 | |
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| 70 | using namespace std; |
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| 71 | |
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| 72 | G4IonCoulombScatteringModel::G4IonCoulombScatteringModel(const G4String& nam) |
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| 73 | : G4VEmModel(nam), |
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| 74 | |
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| 75 | cosThetaMin(1.0), |
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| 76 | isInitialised(false) |
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| 77 | { |
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| 78 | fNistManager = G4NistManager::Instance(); |
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| 79 | theParticleTable = G4ParticleTable::GetParticleTable(); |
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| 80 | theProton = G4Proton::Proton(); |
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| 81 | |
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| 82 | pCuts=0; |
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| 83 | currentMaterial = 0; |
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| 84 | currentElement = 0; |
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| 85 | currentCouple = 0; |
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| 86 | |
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| 87 | lowEnergyLimit = 100*eV; |
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| 88 | recoilThreshold = 0.*eV; |
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| 89 | heavycorr =0; |
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| 90 | particle = 0; |
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| 91 | mass=0; |
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| 92 | |
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| 93 | ioncross = new G4IonCoulombCrossSection(); |
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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 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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| 99 | |
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| 100 | G4IonCoulombScatteringModel::~G4IonCoulombScatteringModel() |
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| 101 | { delete ioncross;} |
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| 102 | |
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| 103 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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| 104 | |
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| 105 | void G4IonCoulombScatteringModel::Initialise(const G4ParticleDefinition* p, |
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| 106 | const G4DataVector& ) |
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| 107 | { |
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| 108 | SetupParticle(p); |
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| 109 | currentCouple = 0; |
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| 110 | cosThetaMin = cos(PolarAngleLimit()); |
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| 111 | ioncross->Initialise(p,cosThetaMin); |
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| 112 | |
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| 113 | pCuts = G4ProductionCutsTable::GetProductionCutsTable()->GetEnergyCutsVector(3); |
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| 114 | |
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| 115 | |
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| 116 | if(!isInitialised) { |
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| 117 | isInitialised = true; |
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| 118 | fParticleChange = GetParticleChangeForGamma(); |
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| 119 | } |
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| 120 | } |
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| 121 | |
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| 122 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo...... |
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| 123 | |
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| 124 | G4double G4IonCoulombScatteringModel::ComputeCrossSectionPerAtom( |
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| 125 | const G4ParticleDefinition* p, |
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| 126 | G4double kinEnergy, |
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| 127 | G4double Z, |
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| 128 | G4double, |
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| 129 | G4double cutEnergy, |
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| 130 | G4double) |
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| 131 | { |
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| 132 | |
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| 133 | SetupParticle(p); |
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| 134 | |
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| 135 | G4double xsec =0.0; |
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| 136 | if(kinEnergy < lowEnergyLimit) return xsec; |
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| 137 | |
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| 138 | DefineMaterial(CurrentCouple()); |
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| 139 | |
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| 140 | G4int iz = G4int(Z); |
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| 141 | |
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| 142 | //from lab to pCM & mu_rel of effective particle |
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| 143 | ioncross->SetupKinematic(kinEnergy, cutEnergy,iz); |
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| 144 | |
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| 145 | |
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| 146 | ioncross->SetupTarget(Z, kinEnergy, heavycorr); |
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| 147 | |
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| 148 | |
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| 149 | xsec = ioncross->NuclearCrossSection(); |
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| 150 | |
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| 151 | //cout<< "..........xsec "<<G4BestUnit(xsec,"Surface") <<endl; |
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| 152 | return xsec; |
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| 153 | } |
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| 154 | |
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| 155 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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| 156 | |
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| 157 | void G4IonCoulombScatteringModel::SampleSecondaries( |
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| 158 | std::vector<G4DynamicParticle*>* fvect, |
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| 159 | const G4MaterialCutsCouple* couple, |
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| 160 | const G4DynamicParticle* dp, |
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| 161 | G4double cutEnergy, |
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| 162 | G4double) |
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| 163 | { |
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| 164 | G4double kinEnergy = dp->GetKineticEnergy(); |
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| 165 | |
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| 166 | if(kinEnergy < lowEnergyLimit) return; |
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| 167 | |
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| 168 | DefineMaterial(couple); |
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| 169 | |
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| 170 | SetupParticle(dp->GetDefinition()); |
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| 171 | |
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| 172 | // Choose nucleus |
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| 173 | currentElement = SelectRandomAtom(couple,particle, |
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| 174 | kinEnergy,cutEnergy,kinEnergy); |
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| 175 | |
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| 176 | G4double Z = currentElement->GetZ(); |
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| 177 | G4int iz = G4int(Z); |
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| 178 | G4int ia = SelectIsotopeNumber(currentElement); |
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| 179 | G4double m2 = G4NucleiProperties::GetNuclearMass(ia, iz); |
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| 180 | |
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| 181 | |
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| 182 | |
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| 183 | G4double xsec= ComputeCrossSectionPerAtom(particle,kinEnergy, Z, |
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| 184 | kinEnergy, cutEnergy, kinEnergy) ; |
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| 185 | if(xsec == 0.0)return; |
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| 186 | |
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| 187 | //scattering angle, z1 == (1-cost) |
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| 188 | G4double z1 = ioncross->SampleCosineTheta(); |
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| 189 | |
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| 190 | if(z1 <= 0.0) { return; } |
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| 191 | |
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| 192 | G4double cost = 1.0 - z1; |
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| 193 | G4double sint = sqrt(z1*(1.0 + cost)); |
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| 194 | G4double phi = twopi * G4UniformRand(); |
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| 195 | |
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| 196 | |
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| 197 | // kinematics in the Lab system |
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| 198 | G4double etot = kinEnergy + mass; |
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| 199 | G4double mom2= kinEnergy*(kinEnergy+2.0*mass); |
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| 200 | G4double ptot = sqrt(mom2); |
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| 201 | |
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| 202 | //CM particle 1 |
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| 203 | G4double bet = ptot/(etot + m2); |
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| 204 | G4double gam = 1.0/sqrt((1.0 - bet)*(1.0 + bet)); |
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| 205 | |
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| 206 | //CM |
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| 207 | G4double momCM2= ioncross->GetMomentum2(); |
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| 208 | G4double momCM =std::sqrt(momCM2); |
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| 209 | //energy & momentum after scattering of incident particle |
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| 210 | G4double pxCM = momCM*sint*cos(phi); |
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| 211 | G4double pyCM = momCM*sint*sin(phi); |
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| 212 | G4double pzCM = momCM*cost; |
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| 213 | G4double eCM = sqrt(momCM2 + mass*mass); |
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| 214 | |
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| 215 | //CM--->Lab |
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| 216 | G4ThreeVector v1(pxCM , pyCM, gam*(pzCM + bet*eCM)); |
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| 217 | G4ThreeVector dir = dp->GetMomentumDirection(); |
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| 218 | |
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| 219 | G4ThreeVector newDirection = v1.unit(); |
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| 220 | newDirection.rotateUz(dir); |
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| 221 | |
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| 222 | fParticleChange->ProposeMomentumDirection(newDirection); |
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| 223 | |
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| 224 | // recoil....................................... |
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| 225 | G4double trec =(1.0 - cost)* m2*(etot*etot - mass*mass )/ |
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| 226 | (mass*mass + m2*m2+ 2.*m2*etot); |
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| 227 | |
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| 228 | G4double finalT = kinEnergy - trec; |
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| 229 | |
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| 230 | |
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| 231 | if(finalT <= lowEnergyLimit) { |
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| 232 | trec = kinEnergy; |
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| 233 | finalT = 0.0; |
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| 234 | } |
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| 235 | |
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| 236 | fParticleChange->SetProposedKineticEnergy(finalT); |
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| 237 | |
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| 238 | G4double tcut = recoilThreshold; |
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| 239 | if(pCuts) { tcut= std::max(tcut,(*pCuts)[currentMaterialIndex]); |
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| 240 | |
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| 241 | //G4cout<<" tcut eV "<<tcut/eV<<endl; |
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| 242 | } |
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| 243 | |
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| 244 | if(trec > tcut) { |
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| 245 | G4ParticleDefinition* ion = theParticleTable->FindIon(iz, ia, 0, iz); |
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| 246 | G4double plab = sqrt(finalT*(finalT + 2.0*mass)); |
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| 247 | G4ThreeVector p2 = (ptot*dir - plab*newDirection).unit(); |
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| 248 | G4DynamicParticle* newdp = new G4DynamicParticle(ion, p2, trec); |
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| 249 | fvect->push_back(newdp); |
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| 250 | } else if(trec > 0.0) { |
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| 251 | fParticleChange->ProposeLocalEnergyDeposit(trec); |
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| 252 | fParticleChange->ProposeNonIonizingEnergyDeposit(trec); |
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| 253 | } |
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| 254 | |
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| 255 | |
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| 256 | } |
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| 257 | |
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| 258 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo...... |
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| 259 | |
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