[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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[1196] | 26 | // $Id: G4CoulombScatteringModel.cc,v 1.43 2009/10/28 10:14:13 vnivanch Exp $ |
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| 27 | // GEANT4 tag $Name: geant4-09-03-cand-01 $ |
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[819] | 28 | // |
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| 29 | // ------------------------------------------------------------------- |
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| 30 | // |
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| 31 | // GEANT4 Class file |
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| 32 | // |
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| 33 | // |
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| 34 | // File name: G4CoulombScatteringModel |
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| 35 | // |
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| 36 | // Author: Vladimir Ivanchenko |
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| 37 | // |
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| 38 | // Creation date: 22.08.2005 |
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| 39 | // |
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| 40 | // Modifications: |
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[1196] | 41 | // |
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[819] | 42 | // 01.08.06 V.Ivanchenko extend upper limit of table to TeV and review the |
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| 43 | // logic of building - only elements from G4ElementTable |
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| 44 | // 08.08.06 V.Ivanchenko build internal table in ekin scale, introduce faclim |
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| 45 | // 19.10.06 V.Ivanchenko use inheritance from G4eCoulombScatteringModel |
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| 46 | // 09.10.07 V.Ivanchenko reorganized methods, add cut dependence in scattering off e- |
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[961] | 47 | // 09.06.08 V.Ivanchenko SelectIsotope is moved to the base class |
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[1196] | 48 | // 16.06.09 Consolandi rows 109, 111-112, 183, 185-186 |
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[819] | 49 | // |
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[1196] | 50 | // |
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[819] | 51 | // Class Description: |
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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 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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| 57 | |
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| 58 | #include "G4CoulombScatteringModel.hh" |
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| 59 | #include "Randomize.hh" |
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| 60 | #include "G4ParticleChangeForGamma.hh" |
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| 61 | #include "G4ParticleTable.hh" |
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| 62 | #include "G4IonTable.hh" |
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| 63 | #include "G4Proton.hh" |
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| 64 | |
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| 65 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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| 66 | |
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| 67 | using namespace std; |
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| 68 | |
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[961] | 69 | G4CoulombScatteringModel::G4CoulombScatteringModel(const G4String& nam) |
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| 70 | : G4eCoulombScatteringModel(nam) |
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| 71 | {} |
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[819] | 72 | |
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| 73 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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| 74 | |
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| 75 | G4CoulombScatteringModel::~G4CoulombScatteringModel() |
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| 76 | {} |
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| 77 | |
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| 78 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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| 79 | |
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| 80 | G4double G4CoulombScatteringModel::ComputeCrossSectionPerAtom( |
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| 81 | const G4ParticleDefinition* p, |
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| 82 | G4double kinEnergy, |
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| 83 | G4double Z, |
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[961] | 84 | G4double, |
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[819] | 85 | G4double cutEnergy, |
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| 86 | G4double) |
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| 87 | { |
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[961] | 88 | SetupParticle(p); |
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[1196] | 89 | if(kinEnergy < lowEnergyLimit) return 0.0; |
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| 90 | SetupKinematic(kinEnergy, cutEnergy); |
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[819] | 91 | |
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[961] | 92 | // save lab system kinematics |
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| 93 | G4double xtkin = tkin; |
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| 94 | G4double xmom2 = mom2; |
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| 95 | G4double xinvb = invbeta2; |
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[819] | 96 | |
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| 97 | // CM system |
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[1055] | 98 | iz = G4int(Z); |
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[961] | 99 | G4double m2 = fNistManager->GetAtomicMassAmu(iz)*amu_c2; |
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[819] | 100 | G4double etot = tkin + mass; |
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| 101 | G4double ptot = sqrt(mom2); |
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| 102 | |
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[961] | 103 | G4double m12 = mass*mass; |
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| 104 | G4double momCM= ptot*m2/sqrt(m12 + m2*m2 + 2.0*etot*m2); |
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[819] | 105 | |
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[961] | 106 | mom2 = momCM*momCM; |
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| 107 | tkin = sqrt(mom2 + m12) - mass; |
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[819] | 108 | |
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[1196] | 109 | //invbeta2 = 1.0 + m12/mom2; |
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| 110 | |
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| 111 | G4double fm = m2/(mass + m2); |
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| 112 | invbeta2 = 1.0 + m12*fm*fm/mom2; |
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| 113 | |
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[961] | 114 | SetupTarget(Z, tkin); |
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[819] | 115 | |
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[961] | 116 | G4double xsec = CrossSectionPerAtom(); |
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[819] | 117 | |
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[961] | 118 | // restore Lab system kinematics |
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| 119 | tkin = xtkin; |
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| 120 | mom2 = xmom2; |
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| 121 | invbeta2 = xinvb; |
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| 122 | |
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| 123 | return xsec; |
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[819] | 124 | } |
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| 125 | |
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| 126 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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| 127 | |
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| 128 | void G4CoulombScatteringModel::SampleSecondaries( |
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| 129 | std::vector<G4DynamicParticle*>* fvect, |
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| 130 | const G4MaterialCutsCouple* couple, |
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| 131 | const G4DynamicParticle* dp, |
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| 132 | G4double cutEnergy, |
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[961] | 133 | G4double) |
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[819] | 134 | { |
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| 135 | G4double kinEnergy = dp->GetKineticEnergy(); |
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[1196] | 136 | if(kinEnergy < lowEnergyLimit) return; |
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[961] | 137 | DefineMaterial(couple); |
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| 138 | SetupParticle(dp->GetDefinition()); |
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[1196] | 139 | SetupKinematic(kinEnergy, cutEnergy); |
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[819] | 140 | |
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[961] | 141 | // Choose nucleus |
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[1196] | 142 | currentElement = SelectRandomAtom(couple,particle, |
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| 143 | kinEnergy,ecut,kinEnergy); |
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[961] | 144 | |
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| 145 | G4double Z = currentElement->GetZ(); |
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[1055] | 146 | iz = G4int(Z); |
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[961] | 147 | G4int ia = SelectIsotopeNumber(currentElement); |
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| 148 | G4double m2 = theParticleTable->GetIonTable()->GetNucleusMass(iz, ia); |
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[819] | 149 | |
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[961] | 150 | // CM system |
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| 151 | G4double etot = tkin + mass; |
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| 152 | G4double ptot = sqrt(mom2); |
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[819] | 153 | |
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[961] | 154 | G4double momCM= ptot*m2/sqrt(mass*mass + m2*m2 + 2.0*etot*m2); |
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| 155 | mom2 = momCM*momCM; |
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| 156 | G4double m12 = mass*mass; |
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| 157 | G4double eCM = sqrt(mom2 + m12); |
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[819] | 158 | |
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[961] | 159 | // a correction for heavy projectile |
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| 160 | G4double fm = m2/(mass + m2); |
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| 161 | invbeta2 = 1.0 + m12*fm*fm/mom2; |
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[819] | 162 | |
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[961] | 163 | // sample scattering angle in CM system |
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| 164 | SetupTarget(Z, eCM - mass); |
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[819] | 165 | |
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[961] | 166 | G4double cost = SampleCosineTheta(); |
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| 167 | G4double z1 = 1.0 - cost; |
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| 168 | if(z1 < 0.0) return; |
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| 169 | G4double sint = sqrt(z1*(1.0 + cost)); |
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| 170 | G4double phi = twopi * G4UniformRand(); |
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[819] | 171 | |
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[961] | 172 | // kinematics in the Lab system |
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| 173 | G4double bet = ptot/(etot + m2); |
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| 174 | G4double gam = 1.0/sqrt((1.0 - bet)*(1.0 + bet)); |
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| 175 | G4double pzCM = momCM*cost; |
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[819] | 176 | |
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[961] | 177 | G4ThreeVector v1(momCM*cos(phi)*sint,momCM*sin(phi)*sint,gam*(pzCM + bet*eCM)); |
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[819] | 178 | G4ThreeVector dir = dp->GetMomentumDirection(); |
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| 179 | G4ThreeVector newDirection = v1.unit(); |
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| 180 | newDirection.rotateUz(dir); |
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| 181 | fParticleChange->ProposeMomentumDirection(newDirection); |
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[961] | 182 | |
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[1196] | 183 | // G4double elab = gam*(eCM + bet*pzCM); |
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[819] | 184 | |
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[1196] | 185 | G4double Ecm = sqrt(mass*mass + m2*m2 + 2.0*etot*m2); |
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| 186 | G4double elab = etot - m2*(ptot/Ecm)*(ptot/Ecm)*(1.-cost) ; |
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| 187 | |
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| 188 | |
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| 189 | G4double finalT = elab - mass; |
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| 190 | if(finalT < 0.0) finalT = 0.0; |
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| 191 | fParticleChange->SetProposedKineticEnergy(finalT); |
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| 192 | |
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[819] | 193 | // recoil |
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[1196] | 194 | G4double erec = kinEnergy - finalT; |
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[961] | 195 | |
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[1196] | 196 | G4double tcut = recoilThreshold; |
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| 197 | if(pCuts) { tcut= std::max(tcut,(*pCuts)[currentMaterialIndex]); } |
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| 198 | |
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| 199 | if(erec > tcut) { |
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[819] | 200 | G4ParticleDefinition* ion = theParticleTable->FindIon(iz, ia, 0, iz); |
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[1196] | 201 | G4double plab = sqrt(finalT*(finalT + 2.0*mass)); |
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[819] | 202 | G4ThreeVector p2 = (ptot*dir - plab*newDirection).unit(); |
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| 203 | G4DynamicParticle* newdp = new G4DynamicParticle(ion, p2, erec); |
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| 204 | fvect->push_back(newdp); |
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| 205 | } else if(erec > 0.0) { |
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| 206 | fParticleChange->ProposeLocalEnergyDeposit(erec); |
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| 207 | fParticleChange->ProposeNonIonizingEnergyDeposit(erec); |
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| 208 | } |
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| 209 | } |
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| 210 | |
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| 211 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo...... |
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| 212 | |
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| 213 | |
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