[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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[961] | 26 | // $Id: G4eCoulombScatteringModel.hh,v 1.36 2008/08/04 08:49:09 vnivanch Exp $ |
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[1007] | 27 | // GEANT4 tag $Name: geant4-09-02 $ |
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[819] | 28 | // |
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| 29 | // ------------------------------------------------------------------- |
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| 30 | // |
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| 31 | // GEANT4 Class header file |
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| 32 | // |
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| 33 | // |
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| 34 | // File name: G4eCoulombScatteringModel |
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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: 19.02.2006 |
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| 39 | // |
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| 40 | // Modifications: |
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| 41 | // 01.08.06 V.Ivanchenko extend upper limit of table to TeV and review the |
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| 42 | // logic of building - only elements from G4ElementTable |
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| 43 | // 08.08.06 V.Ivanchenko build internal table in ekin scale, introduce faclim |
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| 44 | // 19.08.06 V.Ivanchenko add inline function ScreeningParameter and |
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| 45 | // make some members protected |
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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 add SelectIsotope and sampling of the recoil ion |
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[819] | 48 | // |
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| 49 | // Class Description: |
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| 50 | // |
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| 51 | // Implementation of eCoulombScattering of pointlike charge particle |
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| 52 | // on Atomic Nucleus for interval of scattering anles in Lab system |
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| 53 | // thetaMin - ThetaMax, nucleus recoil is neglected. |
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| 54 | // The model based on analysis of J.M.Fernandez-Varea et al. |
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| 55 | // NIM B73(1993)447 originated from G.Wentzel Z.Phys. 40(1927)590 with |
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| 56 | // screening parameter from H.A.Bethe Phys. Rev. 89 (1953) 1256. |
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| 57 | // |
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| 58 | |
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| 59 | // ------------------------------------------------------------------- |
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| 60 | // |
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| 61 | |
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| 62 | #ifndef G4eCoulombScatteringModel_h |
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| 63 | #define G4eCoulombScatteringModel_h 1 |
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| 64 | |
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| 65 | #include "G4VEmModel.hh" |
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| 66 | #include "G4PhysicsTable.hh" |
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| 67 | #include "G4NistManager.hh" |
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| 68 | #include "globals.hh" |
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| 69 | |
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| 70 | class G4ParticleChangeForGamma; |
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| 71 | class G4ParticleDefinition; |
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| 72 | |
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| 73 | class G4eCoulombScatteringModel : public G4VEmModel |
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| 74 | { |
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| 75 | |
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| 76 | public: |
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| 77 | |
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[961] | 78 | G4eCoulombScatteringModel(const G4String& nam = "eCoulombScattering"); |
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[819] | 79 | |
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| 80 | virtual ~G4eCoulombScatteringModel(); |
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| 81 | |
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| 82 | virtual void Initialise(const G4ParticleDefinition*, const G4DataVector&); |
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| 83 | |
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| 84 | virtual G4double ComputeCrossSectionPerAtom( |
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| 85 | const G4ParticleDefinition*, |
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| 86 | G4double kinEnergy, |
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| 87 | G4double Z, |
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| 88 | G4double A, |
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| 89 | G4double cut, |
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| 90 | G4double emax); |
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| 91 | |
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| 92 | virtual void SampleSecondaries(std::vector<G4DynamicParticle*>*, |
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| 93 | const G4MaterialCutsCouple*, |
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| 94 | const G4DynamicParticle*, |
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| 95 | G4double tmin, |
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| 96 | G4double maxEnergy); |
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| 97 | |
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[961] | 98 | inline void SetRecoilThreshold(G4double eth); |
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| 99 | |
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[819] | 100 | protected: |
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| 101 | |
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[961] | 102 | G4double CrossSectionPerAtom(); |
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[819] | 103 | |
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[961] | 104 | G4double SampleCosineTheta(); |
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[819] | 105 | |
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[961] | 106 | inline void DefineMaterial(const G4MaterialCutsCouple*); |
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| 107 | |
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[819] | 108 | inline void SetupParticle(const G4ParticleDefinition*); |
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| 109 | |
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[961] | 110 | inline void SetupKinematic(G4double kinEnergy, G4double cut); |
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[819] | 111 | |
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[961] | 112 | inline void SetupTarget(G4double Z, G4double kinEnergy); |
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[819] | 113 | |
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| 114 | private: |
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| 115 | |
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[961] | 116 | void ComputeMaxElectronScattering(G4double cut); |
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| 117 | |
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[819] | 118 | // hide assignment operator |
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| 119 | G4eCoulombScatteringModel & operator=(const G4eCoulombScatteringModel &right); |
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| 120 | G4eCoulombScatteringModel(const G4eCoulombScatteringModel&); |
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| 121 | |
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| 122 | protected: |
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[961] | 123 | |
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[819] | 124 | const G4ParticleDefinition* theProton; |
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| 125 | const G4ParticleDefinition* theElectron; |
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| 126 | const G4ParticleDefinition* thePositron; |
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| 127 | |
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[961] | 128 | G4ParticleTable* theParticleTable; |
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[819] | 129 | G4ParticleChangeForGamma* fParticleChange; |
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| 130 | G4NistManager* fNistManager; |
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[961] | 131 | const G4DataVector* currentCuts; |
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[819] | 132 | |
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[961] | 133 | const G4MaterialCutsCouple* currentCouple; |
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| 134 | const G4Material* currentMaterial; |
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| 135 | const G4Element* currentElement; |
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| 136 | G4int currentMaterialIndex; |
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| 137 | |
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[819] | 138 | G4double coeff; |
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| 139 | G4double constn; |
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| 140 | G4double cosThetaMin; |
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| 141 | G4double cosThetaMax; |
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[961] | 142 | G4double cosTetMinNuc; |
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[819] | 143 | G4double cosTetMaxNuc; |
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[961] | 144 | G4double cosTetMaxNuc2; |
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[819] | 145 | G4double cosTetMaxElec; |
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[961] | 146 | G4double cosTetMaxElec2; |
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[819] | 147 | G4double q2Limit; |
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[961] | 148 | G4double recoilThreshold; |
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[819] | 149 | G4double elecXSection; |
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| 150 | G4double nucXSection; |
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| 151 | G4double ecut; |
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| 152 | |
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| 153 | // projectile |
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| 154 | const G4ParticleDefinition* particle; |
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| 155 | |
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| 156 | G4double chargeSquare; |
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| 157 | G4double spin; |
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| 158 | G4double mass; |
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| 159 | G4double tkin; |
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| 160 | G4double mom2; |
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| 161 | G4double invbeta2; |
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[961] | 162 | G4double etag; |
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| 163 | G4double lowEnergyLimit; |
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[819] | 164 | |
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| 165 | // target |
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| 166 | G4double targetZ; |
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| 167 | G4double screenZ; |
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| 168 | G4double formfactA; |
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[961] | 169 | G4int idxelm; |
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[819] | 170 | |
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| 171 | private: |
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| 172 | |
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| 173 | G4double a0; |
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| 174 | G4double alpha2; |
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| 175 | G4double faclim; |
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[961] | 176 | G4double FF[100]; |
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[819] | 177 | |
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| 178 | G4bool isInitialised; |
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| 179 | }; |
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| 180 | |
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| 181 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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| 182 | |
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[961] | 183 | inline |
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| 184 | void G4eCoulombScatteringModel::DefineMaterial(const G4MaterialCutsCouple* cup) |
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| 185 | { |
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| 186 | if(cup != currentCouple) { |
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| 187 | currentCouple = cup; |
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| 188 | currentMaterial = cup->GetMaterial(); |
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| 189 | currentMaterialIndex = currentCouple->GetIndex(); |
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| 190 | } |
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| 191 | } |
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| 192 | |
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| 193 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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| 194 | |
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[819] | 195 | inline |
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| 196 | void G4eCoulombScatteringModel::SetupParticle(const G4ParticleDefinition* p) |
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| 197 | { |
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| 198 | // Initialise mass and charge |
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| 199 | if(p != particle) { |
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| 200 | particle = p; |
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| 201 | mass = particle->GetPDGMass(); |
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| 202 | spin = particle->GetPDGSpin(); |
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| 203 | G4double q = particle->GetPDGCharge()/eplus; |
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| 204 | chargeSquare = q*q; |
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| 205 | tkin = 0.0; |
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[961] | 206 | lowEnergyLimit = keV*mass/electron_mass_c2; |
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[819] | 207 | } |
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| 208 | } |
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| 209 | |
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| 210 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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| 211 | |
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[961] | 212 | inline void G4eCoulombScatteringModel::SetupKinematic(G4double ekin, |
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| 213 | G4double cut) |
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[819] | 214 | { |
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[961] | 215 | if(ekin != tkin || ecut != cut) { |
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| 216 | tkin = ekin; |
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| 217 | mom2 = tkin*(tkin + 2.0*mass); |
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[819] | 218 | invbeta2 = 1.0 + mass*mass/mom2; |
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[961] | 219 | cosTetMinNuc = cosThetaMin; |
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| 220 | cosTetMaxNuc = cosThetaMax; |
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| 221 | if(ekin <= 10.*cut && mass < MeV && cosThetaMin < 1.0) { |
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| 222 | cosTetMinNuc = ekin*(cosThetaMin + 1.0)/(10.*cut) - 1.0; |
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| 223 | } |
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| 224 | ComputeMaxElectronScattering(cut); |
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| 225 | } |
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[819] | 226 | } |
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| 227 | |
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| 228 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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| 229 | |
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[961] | 230 | inline void G4eCoulombScatteringModel::SetupTarget(G4double Z, G4double e) |
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[819] | 231 | { |
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[961] | 232 | if(Z != targetZ || e != etag) { |
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| 233 | etag = e; |
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[819] | 234 | targetZ = Z; |
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[961] | 235 | G4int iz= G4int(Z); |
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| 236 | if(iz > 99) iz = 99; |
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| 237 | G4double x = fNistManager->GetZ13(iz); |
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| 238 | screenZ = a0*x*x/mom2; |
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| 239 | if(iz > 1) screenZ *=(1.13 + 3.76*invbeta2*Z*Z*chargeSquare*alpha2); |
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| 240 | //screenZ = a0*x*x*(1.13 + 3.76*Z*Z*chargeSquare*alpha2)/mom2; |
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[819] | 241 | // A.V. Butkevich et al., NIM A 488 (2002) 282 |
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[961] | 242 | formfactA = FF[iz]; |
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| 243 | if(formfactA == 0.0) { |
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| 244 | x = fNistManager->GetA27(iz); |
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| 245 | formfactA = constn*x*x; |
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| 246 | FF[iz] = formfactA; |
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| 247 | } |
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| 248 | formfactA *= mom2; |
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| 249 | cosTetMaxNuc2 = cosTetMaxNuc; |
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| 250 | if(particle == theProton && 1 == iz && cosTetMaxNuc2 < 0.0) { |
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| 251 | cosTetMaxNuc2 = 0.0; |
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| 252 | } |
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| 253 | /* |
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| 254 | G4double ee = 10.*eV*Z; |
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| 255 | if(1 == iz) ee *= 2.0; |
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| 256 | G4double z = std::min(cosTetMaxElec, 1.0 - std::max(ecut,ee)*amu_c2 |
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| 257 | *fNistManager->GetAtomicMassAmu(iz)/mom2); |
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| 258 | cosTetMaxElec2 = std::max(cosTetMaxNuc2, z); |
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| 259 | */ |
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| 260 | cosTetMaxElec2 = cosTetMaxElec; |
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[819] | 261 | } |
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| 262 | } |
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| 263 | |
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| 264 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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| 265 | |
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[961] | 266 | inline void G4eCoulombScatteringModel::SetRecoilThreshold(G4double eth) |
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| 267 | { |
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| 268 | recoilThreshold = eth; |
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| 269 | } |
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| 270 | |
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| 271 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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| 272 | |
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[819] | 273 | #endif |
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