[819] | 1 | // |
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| 2 | // ******************************************************************** |
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| 3 | // * License and Disclaimer * |
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| 4 | // * * |
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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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[1055] | 26 | // $Id: G4ElectroNuclearReaction.hh,v 1.27 2009/02/23 09:49:24 mkossov Exp $ |
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[1228] | 27 | // GEANT4 tag $Name: geant4-09-03 $ |
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[819] | 28 | // |
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[1055] | 29 | // GEANT4 physics class: G4ElectroNuclearReaction -- header file for CHIPS |
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| 30 | // Created: J.P. Wellisch, following M. Kossov's algorithm. 12/11/2001 |
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[819] | 31 | // The last update: J.P. Wellisch, 06-June-02 |
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[1055] | 32 | // 17.02.2009 M.Kossov, now it is recommended to use the G4QCollision process |
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[819] | 33 | // |
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| 34 | #ifndef G4ElectroNuclearReaction_h |
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[962] | 35 | #define G4ElectroNuclearReaction_h 1 |
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[819] | 36 | |
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| 37 | #include "globals.hh" |
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| 38 | #include "G4HadronicInteraction.hh" |
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| 39 | #include "G4ChiralInvariantPhaseSpace.hh" |
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| 40 | #include "G4ElectroNuclearCrossSection.hh" |
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| 41 | #include "G4PhotoNuclearCrossSection.hh" |
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[962] | 42 | #include "G4GammaParticipants.hh" |
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| 43 | #include "G4QGSModel.hh" |
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| 44 | #include "G4QGSMFragmentation.hh" |
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| 45 | #include "G4Nucleus.hh" |
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| 46 | #include "G4HadFinalState.hh" |
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| 47 | #include "G4HadProjectile.hh" |
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[819] | 48 | #include "G4Electron.hh" |
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| 49 | #include "G4Positron.hh" |
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| 50 | #include "G4Gamma.hh" |
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| 51 | #include "G4TheoFSGenerator.hh" |
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| 52 | #include "G4GeneratorPrecompoundInterface.hh" |
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| 53 | #include "G4ExcitedStringDecay.hh" |
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[962] | 54 | |
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[819] | 55 | class G4ElectroNuclearReaction : public G4HadronicInteraction |
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| 56 | { |
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[962] | 57 | public: |
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| 58 | |
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| 59 | G4ElectroNuclearReaction():G4HadronicInteraction("CHIPS") |
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| 60 | { |
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| 61 | SetMinEnergy(0*GeV); |
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| 62 | SetMaxEnergy(30*TeV); |
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[819] | 63 | |
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[962] | 64 | theHEModel = new G4TheoFSGenerator; |
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| 65 | theCascade = new G4GeneratorPrecompoundInterface; |
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| 66 | theHEModel->SetTransport(theCascade); |
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| 67 | theHEModel->SetHighEnergyGenerator(&theStringModel); |
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| 68 | theStringDecay = new G4ExcitedStringDecay(&theFragmentation); |
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| 69 | theStringModel.SetFragmentationModel(theStringDecay); |
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| 70 | theHEModel->SetMinEnergy(2.5*GeV); |
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| 71 | theHEModel->SetMaxEnergy(100*TeV); |
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| 72 | } |
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| 73 | |
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[1055] | 74 | virtual ~G4ElectroNuclearReaction() {delete theStringDecay;}; |
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[819] | 75 | |
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[962] | 76 | G4HadFinalState* ApplyYourself(const G4HadProjectile& aTrack, |
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[1055] | 77 | G4Nucleus& aTargetNucleus); |
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[819] | 78 | |
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[962] | 79 | private: |
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| 80 | |
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| 81 | G4ChiralInvariantPhaseSpace theLEModel; |
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| 82 | G4TheoFSGenerator * theHEModel; |
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| 83 | G4GeneratorPrecompoundInterface * theCascade; |
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| 84 | G4QGSModel< G4GammaParticipants > theStringModel; |
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| 85 | G4QGSMFragmentation theFragmentation; |
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| 86 | G4ExcitedStringDecay * theStringDecay; |
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| 87 | G4ElectroNuclearCrossSection theElectronData; |
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| 88 | G4PhotoNuclearCrossSection thePhotonData; |
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| 89 | G4HadFinalState theResult; |
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[819] | 90 | }; |
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| 91 | |
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[962] | 92 | inline |
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| 93 | G4HadFinalState* G4ElectroNuclearReaction::ApplyYourself(const G4HadProjectile& aTrack, |
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[1055] | 94 | G4Nucleus& aTargetNucleus) |
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[819] | 95 | { |
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| 96 | theResult.Clear(); |
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[1055] | 97 | static const G4double dM=G4Proton::Proton()->GetPDGMass()+ |
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| 98 | G4Neutron::Neutron()->GetPDGMass(); // MeanDoubleNucleon Mass = m_n+m_p (@@ no binding) |
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| 99 | static const G4double me=G4Electron::Electron()->GetPDGMass(); // electron mass |
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| 100 | static const G4double me2=me*me; // squared electron mass |
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[819] | 101 | G4DynamicParticle theTempEl(const_cast<G4ParticleDefinition *>(aTrack.GetDefinition()), |
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| 102 | aTrack.Get4Momentum().vect()); |
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| 103 | const G4DynamicParticle* theElectron=&theTempEl; |
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| 104 | const G4ParticleDefinition* aD = theElectron->GetDefinition(); |
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| 105 | if((aD != G4Electron::ElectronDefinition()) && (aD != G4Positron::PositronDefinition())) |
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[1055] | 106 | throw G4HadronicException(__FILE__, __LINE__, |
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| 107 | "G4ElectroNuclearReaction::ApplyYourself called for neither electron or positron"); |
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[819] | 108 | const G4ElementTable* aTab = G4Element::GetElementTable(); |
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| 109 | G4Element * anElement = 0; |
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| 110 | G4int aZ = static_cast<G4int>(aTargetNucleus.GetZ()+.1); |
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| 111 | for(size_t ii=0; ii<aTab->size(); ii++) |
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| 112 | { |
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| 113 | if ( std::abs((*aTab)[ii]->GetZ()-aZ) < .1) |
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| 114 | { |
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| 115 | anElement = (*aTab)[ii]; |
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| 116 | break; |
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| 117 | } |
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| 118 | } |
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| 119 | if(0==anElement) |
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| 120 | { |
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[1055] | 121 | G4cerr<<"***G4ElectroNuclearReaction::ApplyYourself: element with Z=" |
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| 122 | <<aTargetNucleus.GetZ()<<" is not in the element table"<<G4endl; |
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[819] | 123 | throw G4HadronicException(__FILE__, __LINE__, "Anomalous element error."); |
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| 124 | } |
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| 125 | |
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| 126 | // Note: high energy gamma nuclear now implemented. |
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[1055] | 127 | G4double xSec = theElectronData.GetCrossSection(theElectron, anElement);// Check XSection |
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[819] | 128 | if(xSec<=0.) |
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| 129 | { |
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| 130 | theResult.SetStatusChange(isAlive); |
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| 131 | theResult.SetEnergyChange(theElectron->GetKineticEnergy()); |
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[1055] | 132 | // new direction for the electron |
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| 133 | theResult.SetMomentumChange(theElectron->GetMomentumDirection()); |
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[819] | 134 | return &theResult; // DO-NOTHING condition |
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| 135 | } |
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| 136 | G4double photonEnergy = theElectronData.GetEquivalentPhotonEnergy(); |
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| 137 | G4double theElectronKinEnergy=theElectron->GetKineticEnergy(); |
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| 138 | if( theElectronKinEnergy < photonEnergy ) |
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| 139 | { |
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[1055] | 140 | G4cout<<"G4ElectroNuclearReaction::ApplyYourself: photonEnergy is very high"<<G4endl; |
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| 141 | G4cout<<">>> If this condition persists, please contact Geant4 group"<<G4endl; |
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[819] | 142 | theResult.SetStatusChange(isAlive); |
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| 143 | theResult.SetEnergyChange(theElectron->GetKineticEnergy()); |
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[1055] | 144 | // new direction for the electron |
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| 145 | theResult.SetMomentumChange(theElectron->GetMomentumDirection()); |
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[819] | 146 | return &theResult; // DO-NOTHING condition |
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| 147 | } |
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| 148 | G4double photonQ2 = theElectronData.GetEquivalentPhotonQ2(photonEnergy); |
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[1055] | 149 | G4double W=photonEnergy-photonQ2/dM; // Hadronic energy flow from the virtual photon |
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[819] | 150 | if(getenv("debug_G4ElectroNuclearReaction") ) |
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| 151 | { |
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| 152 | G4cout << "G4ElectroNuclearReaction: Equivalent Energy = "<<W<<G4endl; |
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| 153 | } |
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| 154 | if(W<0.) |
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| 155 | { |
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| 156 | theResult.SetStatusChange(isAlive); |
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| 157 | theResult.SetEnergyChange(theElectron->GetKineticEnergy()); |
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[1055] | 158 | // new direction for the electron |
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| 159 | theResult.SetMomentumChange(theElectron->GetMomentumDirection()); |
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[819] | 160 | return &theResult; // DO-NOTHING condition |
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[1055] | 161 | throw G4HadronicException(__FILE__, __LINE__, |
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| 162 | "G4ElectroNuclearReaction::ApplyYourself: negative equivalent energy"); |
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[819] | 163 | } |
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| 164 | G4DynamicParticle* theDynamicPhoton = new |
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| 165 | G4DynamicParticle(G4Gamma::GammaDefinition(), |
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[1055] | 166 | G4ParticleMomentum(1.,0.,0.), photonEnergy*MeV); //----->-* |
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[819] | 167 | G4double sigNu=thePhotonData.GetCrossSection(theDynamicPhoton, anElement); // | |
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| 168 | theDynamicPhoton->SetKineticEnergy(W); // Redefine photon with equivalent energy | |
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| 169 | G4double sigK =thePhotonData.GetCrossSection(theDynamicPhoton, anElement); // | |
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| 170 | delete theDynamicPhoton; // <-------------------------------------------------------* |
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| 171 | G4double rndFraction = theElectronData.GetVirtualFactor(photonEnergy, photonQ2); |
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| 172 | if(sigNu*G4UniformRand()>sigK*rndFraction) |
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| 173 | { |
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| 174 | theResult.SetStatusChange(isAlive); |
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| 175 | theResult.SetEnergyChange(theElectron->GetKineticEnergy()); |
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[1055] | 176 | // new direction for the electron |
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| 177 | theResult.SetMomentumChange(theElectron->GetMomentumDirection()); |
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[819] | 178 | return &theResult; // DO-NOTHING condition |
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| 179 | } |
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| 180 | theResult.SetStatusChange(isAlive); |
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| 181 | // Scatter an electron and make gamma+A reaction |
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| 182 | G4double iniE=theElectronKinEnergy+me; // Initial total energy of electron |
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| 183 | G4double finE=iniE-photonEnergy; // Final total energy of electron |
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[1055] | 184 | theResult.SetEnergyChange(std::max(0.,finE-me)); // Modifies the KINETIC ENERGY |
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[819] | 185 | G4double EEm=iniE*finE-me2; // Just an intermediate value to avoid "2*" |
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[1055] | 186 | G4double iniP=std::sqrt(iniE*iniE-me2); // Initial momentum of the electron |
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| 187 | G4double finP=std::sqrt(finE*finE-me2); // Final momentum of the electron |
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| 188 | G4double cost=(EEm+EEm-photonQ2)/iniP/finP;// std::cos(theta) for the electron scattering |
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[819] | 189 | if(cost>1.) cost=1.; |
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| 190 | if(cost<-1.) cost=-1.; |
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| 191 | G4ThreeVector dir=theElectron->GetMomentumDirection(); // Direction of primary electron |
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| 192 | G4ThreeVector ort=dir.orthogonal(); // Not normed orthogonal vector (!) (to dir) |
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| 193 | G4ThreeVector ortx = ort.unit(); // First unit vector orthogonal to the direction |
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| 194 | G4ThreeVector orty = dir.cross(ortx); // Second unit vector orthoganal to the direction |
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| 195 | G4double sint=std::sqrt(1.-cost*cost); // Perpendicular component |
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[1055] | 196 | G4double phi=twopi*G4UniformRand(); // phi of scattered electron |
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[819] | 197 | G4double sinx=sint*std::sin(phi); // x-component |
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| 198 | G4double siny=sint*std::cos(phi); // y-component |
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| 199 | G4ThreeVector findir=cost*dir+sinx*ortx+siny*orty; |
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| 200 | theResult.SetMomentumChange(findir); // new direction for the electron |
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| 201 | G4ThreeVector photonMomentum=iniP*dir-finP*findir; |
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| 202 | G4DynamicParticle localGamma(G4Gamma::GammaDefinition(), photonEnergy, photonMomentum); |
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[1055] | 203 | //G4DynamicParticle localGamma(G4Gamma::GammaDefinition(),photonDirection, photonEnergy); |
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[819] | 204 | //G4DynamicParticle localGamma(G4Gamma::GammaDefinition(), photonLorentzVector); |
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| 205 | G4ThreeVector position(0,0,0); |
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| 206 | G4HadProjectile localTrack(localGamma); |
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| 207 | G4HadFinalState * result; |
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| 208 | if(photonEnergy < 3*GeV) |
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| 209 | { |
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| 210 | result = theLEModel.ApplyYourself(localTrack, aTargetNucleus, &theResult); |
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| 211 | } |
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| 212 | else |
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| 213 | { |
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| 214 | // G4cout << "0) Getting a high energy electro-nuclear reaction"<<G4endl; |
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| 215 | G4HadFinalState * aResult = theHEModel->ApplyYourself(localTrack, aTargetNucleus); |
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| 216 | for(G4int all = 0; all < aResult->GetNumberOfSecondaries(); all++) |
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| 217 | { |
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| 218 | theResult.AddSecondary(aResult->GetSecondary(all)); |
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| 219 | } |
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| 220 | aResult->SecondariesAreStale(); |
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| 221 | result = &theResult; |
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| 222 | } |
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| 223 | return result; |
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| 224 | } |
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| 225 | |
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| 226 | #endif |
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