[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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[1315] | 26 | // $Id: G4HadronElastic.cc,v 1.66 2010/01/13 15:42:06 mkossov Exp $ |
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[1340] | 27 | // GEANT4 tag $Name: geant4-09-03-ref-09 $ |
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[819] | 28 | // |
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| 29 | // |
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| 30 | // Physics model class G4HadronElastic (derived from G4LElastic) |
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| 31 | // |
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| 32 | // |
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| 33 | // G4 Model: Low-energy Elastic scattering with 4-momentum balance |
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| 34 | // F.W. Jones, TRIUMF, 04-JUN-96 |
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| 35 | // Uses G4ElasticHadrNucleusHE and G4VQCrossSection |
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| 36 | // |
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| 37 | // |
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| 38 | // 25-JUN-98 FWJ: replaced missing Initialize for ParticleChange. |
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| 39 | // 09-Set-05 V.Ivanchenko HARP version of the model: fix scattering |
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| 40 | // on hydrogen, use relativistic Lorentz transformation |
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| 41 | // 24-Nov-05 V.Ivanchenko sample cost in center of mass reference system |
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| 42 | // 03-Dec-05 V.Ivanchenko add protection to initial momentum 20 MeV/c in |
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| 43 | // center of mass system (before it was in lab system) |
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| 44 | // below model is not valid |
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| 45 | // 14-Dec-05 V.Ivanchenko change protection to cos(theta) < -1 and |
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| 46 | // rename the class |
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| 47 | // 13-Apr-06 V.Ivanchenko move to coherent_elastic subdirectory; remove |
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| 48 | // charge exchange; remove limitation on incident momentum; |
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| 49 | // add s-wave regim below some momentum |
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| 50 | // 24-Apr-06 V.Ivanchenko add neutron scattering on hydrogen from CHIPS |
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| 51 | // 07-Jun-06 V.Ivanchenko fix problem of rotation |
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| 52 | // 25-Jul-06 V.Ivanchenko add 19 MeV low energy, below which S-wave is sampled |
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| 53 | // 02-Aug-06 V.Ivanchenko introduce energy cut on the aria of S-wave for pions |
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| 54 | // 24-Aug-06 V.Ivanchenko switch on G4ElasticHadrNucleusHE |
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| 55 | // 31-Aug-06 V.Ivanchenko do not sample sacttering for particles with kinetic |
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| 56 | // energy below 10 keV |
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| 57 | // 16-Nov-06 V.Ivanchenko Simplify logic of choosing of the model for sampling |
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| 58 | // 30-Mar-07 V.Ivanchenko lowEnergyLimitQ=0, lowEnergyLimitHE = 1.0*GeV, |
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| 59 | // lowestEnergyLimit= 0 |
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| 60 | // 04-May-07 V.Ivanchenko do not use HE model for hydrogen target to avoid NaN; |
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| 61 | // use QElastic for p, n incident for any energy for |
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| 62 | // p and He targets only |
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| 63 | // 11-May-07 V.Ivanchenko remove unused method Defs1 |
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[1315] | 64 | // 13.01.10: M.Kosov: Use G4Q(Pr/Neut)ElasticCS instead of G4QElasticCS |
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[819] | 65 | // |
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| 66 | |
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| 67 | #include "G4HadronElastic.hh" |
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| 68 | #include "G4ParticleTable.hh" |
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| 69 | #include "G4ParticleDefinition.hh" |
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| 70 | #include "G4IonTable.hh" |
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[1315] | 71 | #include "G4QProtonElasticCrossSection.hh" |
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| 72 | #include "G4QNeutronElasticCrossSection.hh" |
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[819] | 73 | #include "G4VQCrossSection.hh" |
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| 74 | #include "G4ElasticHadrNucleusHE.hh" |
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| 75 | #include "Randomize.hh" |
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| 76 | #include "G4Proton.hh" |
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| 77 | #include "G4Neutron.hh" |
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| 78 | #include "G4Deuteron.hh" |
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| 79 | #include "G4Alpha.hh" |
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| 80 | #include "G4PionPlus.hh" |
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| 81 | #include "G4PionMinus.hh" |
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| 82 | |
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[1315] | 83 | G4VQCrossSection* G4HadronElastic::pCManager = 0; |
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| 84 | G4VQCrossSection* G4HadronElastic::nCManager = 0; |
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[1196] | 85 | |
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[819] | 86 | G4HadronElastic::G4HadronElastic(G4ElasticHadrNucleusHE* HModel) |
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| 87 | : G4HadronicInteraction("G4HadronElastic"), hElastic(HModel) |
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| 88 | { |
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| 89 | SetMinEnergy( 0.0*GeV ); |
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| 90 | SetMaxEnergy( 100.*TeV ); |
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| 91 | verboseLevel= 0; |
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| 92 | lowEnergyRecoilLimit = 100.*keV; |
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| 93 | lowEnergyLimitQ = 0.0*GeV; |
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| 94 | lowEnergyLimitHE = 1.0*GeV; |
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| 95 | lowestEnergyLimit= 1.e-6*eV; |
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| 96 | plabLowLimit = 20.0*MeV; |
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| 97 | |
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[1315] | 98 | if(!pCManager) |
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| 99 | { |
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| 100 | pCManager = G4QProtonElasticCrossSection::GetPointer(); |
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| 101 | nCManager = G4QNeutronElasticCrossSection::GetPointer(); |
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| 102 | } |
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[819] | 103 | if(!hElastic) hElastic = new G4ElasticHadrNucleusHE(); |
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| 104 | |
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| 105 | theProton = G4Proton::Proton(); |
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| 106 | theNeutron = G4Neutron::Neutron(); |
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| 107 | theDeuteron = G4Deuteron::Deuteron(); |
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| 108 | theAlpha = G4Alpha::Alpha(); |
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| 109 | thePionPlus = G4PionPlus::PionPlus(); |
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| 110 | thePionMinus= G4PionMinus::PionMinus(); |
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[962] | 111 | |
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[819] | 112 | } |
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| 113 | |
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| 114 | G4HadronElastic::~G4HadronElastic() |
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| 115 | { |
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| 116 | delete hElastic; |
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| 117 | } |
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| 118 | |
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| 119 | G4VQCrossSection* G4HadronElastic::GetCS() |
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| 120 | { |
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[1315] | 121 | return pCManager; |
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| 122 | //if (PDG==2212) return pCManager; |
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| 123 | //else if(PDG==2112) return nCManager; |
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| 124 | //return 0; |
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[819] | 125 | } |
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| 126 | |
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| 127 | G4ElasticHadrNucleusHE* G4HadronElastic::GetHElastic() |
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| 128 | { |
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| 129 | return hElastic; |
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| 130 | } |
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| 131 | |
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| 132 | G4HadFinalState* G4HadronElastic::ApplyYourself( |
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| 133 | const G4HadProjectile& aTrack, G4Nucleus& targetNucleus) |
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| 134 | { |
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| 135 | theParticleChange.Clear(); |
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| 136 | |
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| 137 | const G4HadProjectile* aParticle = &aTrack; |
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| 138 | G4double ekin = aParticle->GetKineticEnergy(); |
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| 139 | if(ekin <= lowestEnergyLimit) { |
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| 140 | theParticleChange.SetEnergyChange(ekin); |
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| 141 | theParticleChange.SetMomentumChange(aTrack.Get4Momentum().vect().unit()); |
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| 142 | return &theParticleChange; |
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| 143 | } |
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| 144 | |
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| 145 | G4double aTarget = targetNucleus.GetN(); |
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| 146 | G4double zTarget = targetNucleus.GetZ(); |
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| 147 | |
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| 148 | G4double plab = aParticle->GetTotalMomentum(); |
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| 149 | if (verboseLevel >1) { |
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| 150 | G4cout << "G4HadronElastic::DoIt: Incident particle plab=" |
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| 151 | << plab/GeV << " GeV/c " |
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| 152 | << " ekin(MeV) = " << ekin/MeV << " " |
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| 153 | << aParticle->GetDefinition()->GetParticleName() << G4endl; |
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| 154 | } |
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| 155 | // Scattered particle referred to axis of incident particle |
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| 156 | const G4ParticleDefinition* theParticle = aParticle->GetDefinition(); |
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| 157 | G4double m1 = theParticle->GetPDGMass(); |
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| 158 | |
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| 159 | G4int Z = static_cast<G4int>(zTarget+0.5); |
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| 160 | G4int A = static_cast<G4int>(aTarget+0.5); |
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| 161 | G4int N = A - Z; |
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| 162 | G4int projPDG = theParticle->GetPDGEncoding(); |
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[962] | 163 | if (verboseLevel>1) { |
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[819] | 164 | G4cout << "G4HadronElastic for " << theParticle->GetParticleName() |
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| 165 | << " PDGcode= " << projPDG << " on nucleus Z= " << Z |
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| 166 | << " A= " << A << " N= " << N |
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| 167 | << G4endl; |
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[962] | 168 | } |
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[819] | 169 | G4ParticleDefinition * theDef = 0; |
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| 170 | |
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| 171 | if(Z == 1 && A == 1) theDef = theProton; |
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| 172 | else if (Z == 1 && A == 2) theDef = theDeuteron; |
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| 173 | else if (Z == 1 && A == 3) theDef = G4Triton::Triton(); |
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| 174 | else if (Z == 2 && A == 3) theDef = G4He3::He3(); |
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| 175 | else if (Z == 2 && A == 4) theDef = theAlpha; |
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| 176 | else theDef = G4ParticleTable::GetParticleTable()->FindIon(Z,A,0,Z); |
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| 177 | |
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| 178 | G4double m2 = theDef->GetPDGMass(); |
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| 179 | G4LorentzVector lv1 = aParticle->Get4Momentum(); |
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| 180 | G4LorentzVector lv(0.0,0.0,0.0,m2); |
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| 181 | lv += lv1; |
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| 182 | |
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| 183 | G4ThreeVector bst = lv.boostVector(); |
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| 184 | lv1.boost(-bst); |
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| 185 | |
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| 186 | G4ThreeVector p1 = lv1.vect(); |
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| 187 | G4double ptot = p1.mag(); |
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| 188 | G4double tmax = 4.0*ptot*ptot; |
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| 189 | G4double t = 0.0; |
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| 190 | |
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| 191 | // Choose generator |
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| 192 | G4ElasticGenerator gtype = fLElastic; |
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| 193 | |
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| 194 | // Q-elastic for p,n scattering on H and He |
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[962] | 195 | if (theParticle == theProton || theParticle == theNeutron) { |
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[819] | 196 | // && Z <= 2 && ekin >= lowEnergyLimitQ) |
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| 197 | gtype = fQElastic; |
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| 198 | |
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[962] | 199 | } else { |
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[819] | 200 | // S-wave for very low energy |
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| 201 | if(plab < plabLowLimit) gtype = fSWave; |
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| 202 | // HE-elastic for energetic projectile mesons |
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| 203 | else if(ekin >= lowEnergyLimitHE && theParticle->GetBaryonNumber() == 0) |
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[962] | 204 | { gtype = fHElastic; } |
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[819] | 205 | } |
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| 206 | |
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| 207 | // |
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| 208 | // Sample t |
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| 209 | // |
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| 210 | if(gtype == fQElastic) { |
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| 211 | if (verboseLevel >1) { |
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[1315] | 212 | G4cout << "G4HadronElastic: Z= " << Z << " N= " << N << " pdg= " << projPDG |
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| 213 | << " mom(GeV)= " << plab/GeV<<", pC="<<pCManager<<", nC="<<nCManager<<G4endl; |
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[819] | 214 | } |
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| 215 | if(Z == 1 && N == 2) N = 1; |
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| 216 | else if(Z == 2 && N == 1) N = 2; |
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[1315] | 217 | G4double cs = 0.; |
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| 218 | if (projPDG==2212) cs = pCManager->GetCrossSection(false,plab,Z,N,projPDG); |
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| 219 | else if(projPDG==2112) cs = nCManager->GetCrossSection(false,plab,Z,N,projPDG); |
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[819] | 220 | |
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| 221 | // check if cross section is reasonable |
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[1315] | 222 | if(cs > 0.0) |
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| 223 | { |
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| 224 | if (projPDG==2212) t = pCManager->GetExchangeT(Z,N,projPDG); |
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| 225 | else if(projPDG==2112) t = nCManager->GetExchangeT(Z,N,projPDG); |
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| 226 | } |
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[819] | 227 | else if(plab > plabLowLimit) gtype = fLElastic; |
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| 228 | else gtype = fSWave; |
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| 229 | } |
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| 230 | |
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| 231 | if(gtype == fLElastic) { |
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[962] | 232 | G4double g2 = GeV*GeV; |
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| 233 | t = g2*SampleT(tmax/g2,m1,m2,aTarget); |
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[819] | 234 | } |
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| 235 | |
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| 236 | // use mean atomic number |
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| 237 | if(gtype == fHElastic) { |
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| 238 | t = hElastic->SampleT(theParticle,plab,Z,A); |
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| 239 | } |
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| 240 | |
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| 241 | if(gtype == fSWave) t = G4UniformRand()*tmax; |
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| 242 | |
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[962] | 243 | if(verboseLevel>1) { |
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[819] | 244 | G4cout <<"type= " << gtype <<" t= " << t << " tmax= " << tmax |
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| 245 | << " ptot= " << ptot << G4endl; |
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[962] | 246 | } |
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[819] | 247 | // Sampling in CM system |
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| 248 | G4double phi = G4UniformRand()*twopi; |
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| 249 | G4double cost = 1. - 2.0*t/tmax; |
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| 250 | G4double sint; |
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| 251 | |
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[962] | 252 | // problem in sampling |
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[1196] | 253 | if(cost > 1.0 || cost < -1.0) { |
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| 254 | if(verboseLevel > 0) { |
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| 255 | G4cout << "G4HadronElastic:WARNING: Z= " << Z << " N= " |
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| 256 | << N << " " << aParticle->GetDefinition()->GetParticleName() |
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| 257 | << " mom(GeV)= " << plab/GeV |
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| 258 | << " the model type " << gtype; |
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| 259 | if(gtype == fQElastic) G4cout << " CHIPS "; |
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| 260 | else if(gtype == fLElastic) G4cout << " LElastic "; |
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| 261 | else if(gtype == fHElastic) G4cout << " HElastic "; |
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| 262 | G4cout << " cost= " << cost |
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| 263 | << G4endl; |
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| 264 | } |
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[819] | 265 | cost = 1.0; |
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| 266 | sint = 0.0; |
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[962] | 267 | |
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| 268 | // normal situation |
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| 269 | } else { |
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[819] | 270 | sint = std::sqrt((1.0-cost)*(1.0+cost)); |
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| 271 | } |
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[962] | 272 | if (verboseLevel>1) { |
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[819] | 273 | G4cout << "cos(t)=" << cost << " std::sin(t)=" << sint << G4endl; |
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[962] | 274 | } |
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[819] | 275 | G4ThreeVector v1(sint*std::cos(phi),sint*std::sin(phi),cost); |
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| 276 | v1 *= ptot; |
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| 277 | G4LorentzVector nlv1(v1.x(),v1.y(),v1.z(),std::sqrt(ptot*ptot + m1*m1)); |
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| 278 | |
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| 279 | nlv1.boost(bst); |
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| 280 | |
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| 281 | G4double eFinal = nlv1.e() - m1; |
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| 282 | if (verboseLevel > 1) { |
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| 283 | G4cout << "Scattered: " |
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| 284 | << nlv1<<" m= " << m1 << " ekin(MeV)= " << eFinal |
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| 285 | << " Proj: 4-mom " << lv1 |
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| 286 | <<G4endl; |
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| 287 | } |
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| 288 | if(eFinal <= lowestEnergyLimit) { |
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[962] | 289 | if(eFinal < 0.0 && verboseLevel > 0) { |
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[819] | 290 | G4cout << "G4HadronElastic WARNING ekin= " << eFinal |
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| 291 | << " after scattering of " |
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| 292 | << aParticle->GetDefinition()->GetParticleName() |
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| 293 | << " p(GeV/c)= " << plab |
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| 294 | << " on " << theDef->GetParticleName() |
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| 295 | << G4endl; |
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| 296 | } |
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| 297 | theParticleChange.SetEnergyChange(0.0); |
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| 298 | nlv1 = G4LorentzVector(0.0,0.0,0.0,m1); |
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| 299 | |
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| 300 | } else { |
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| 301 | theParticleChange.SetMomentumChange(nlv1.vect().unit()); |
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| 302 | theParticleChange.SetEnergyChange(eFinal); |
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| 303 | } |
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| 304 | |
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| 305 | G4LorentzVector nlv0 = lv - nlv1; |
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| 306 | G4double erec = nlv0.e() - m2; |
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| 307 | if (verboseLevel > 1) { |
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| 308 | G4cout << "Recoil: " |
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| 309 | << nlv0<<" m= " << m2 << " ekin(MeV)= " << erec |
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| 310 | <<G4endl; |
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| 311 | } |
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| 312 | if(erec > lowEnergyRecoilLimit) { |
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| 313 | G4DynamicParticle * aSec = new G4DynamicParticle(theDef, nlv0); |
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| 314 | theParticleChange.AddSecondary(aSec); |
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| 315 | } else { |
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| 316 | if(erec < 0.0) erec = 0.0; |
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| 317 | theParticleChange.SetLocalEnergyDeposit(erec); |
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| 318 | } |
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| 319 | |
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| 320 | return &theParticleChange; |
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| 321 | } |
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| 322 | |
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| 323 | G4double |
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[962] | 324 | G4HadronElastic::SampleT(G4double tmax, G4double, G4double, G4double atno2) |
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[819] | 325 | { |
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| 326 | // G4cout << "Entering elastic scattering 2"<<G4endl; |
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| 327 | // Compute the direction of elastic scattering. |
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| 328 | // It is planned to replace this code with a method based on |
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| 329 | // parameterized functions and a Monte Carlo method to invert the CDF. |
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| 330 | |
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[962] | 331 | // G4double ran = G4UniformRand(); |
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[819] | 332 | G4double aa, bb, cc, dd, rr; |
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| 333 | if (atno2 <= 62.) { |
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| 334 | aa = std::pow(atno2, 1.63); |
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| 335 | bb = 14.5*std::pow(atno2, 0.66); |
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| 336 | cc = 1.4*std::pow(atno2, 0.33); |
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| 337 | dd = 10.; |
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| 338 | } else { |
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| 339 | aa = std::pow(atno2, 1.33); |
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| 340 | bb = 60.*std::pow(atno2, 0.33); |
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| 341 | cc = 0.4*std::pow(atno2, 0.40); |
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| 342 | dd = 10.; |
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| 343 | } |
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| 344 | aa = aa/bb; |
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| 345 | cc = cc/dd; |
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[962] | 346 | G4double ran, t1, t2; |
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| 347 | do { |
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| 348 | ran = G4UniformRand(); |
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| 349 | t1 = -std::log(ran)/bb; |
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| 350 | t2 = -std::log(ran)/dd; |
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| 351 | } while(t1 > tmax || t2 > tmax); |
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| 352 | |
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[819] | 353 | rr = (aa + cc)*ran; |
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[962] | 354 | |
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[819] | 355 | if (verboseLevel > 1) { |
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| 356 | G4cout << "DoIt: aa,bb,cc,dd,rr" << G4endl; |
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| 357 | G4cout << aa << " " << bb << " " << cc << " " << dd << " " << rr << G4endl; |
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| 358 | G4cout << "t1,Fctcos " << t1 << " " << Fctcos(t1, aa, bb, cc, dd, rr) << G4endl; |
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| 359 | G4cout << "t2,Fctcos " << t2 << " " << Fctcos(t2, aa, bb, cc, dd, rr) << G4endl; |
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| 360 | } |
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| 361 | G4double eps = 0.001; |
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| 362 | G4int ind1 = 10; |
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| 363 | G4double t = 0.0; |
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| 364 | G4int ier1; |
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| 365 | ier1 = Rtmi(&t, t1, t2, eps, ind1, |
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| 366 | aa, bb, cc, dd, rr); |
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| 367 | if (verboseLevel > 1) { |
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[962] | 368 | G4cout << "From Rtmi, ier1=" << ier1 << " t= " << t << G4endl; |
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[819] | 369 | G4cout << "t, Fctcos " << t << " " << Fctcos(t, aa, bb, cc, dd, rr) << G4endl; |
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| 370 | } |
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| 371 | if (ier1 != 0) t = 0.25*(3.*t1 + t2); |
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| 372 | if (verboseLevel > 1) { |
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| 373 | G4cout << "t, Fctcos " << t << " " << Fctcos(t, aa, bb, cc, dd, rr) << |
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| 374 | G4endl; |
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| 375 | } |
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| 376 | return t; |
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| 377 | } |
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| 378 | |
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| 379 | // The following is a "translation" of a root-finding routine |
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| 380 | // from GEANT3.21/GHEISHA. Some of the labelled block structure has |
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| 381 | // been retained for clarity. This routine will not be needed after |
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| 382 | // the planned revisions to DoIt(). |
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| 383 | |
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| 384 | G4int |
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| 385 | G4HadronElastic::Rtmi(G4double* x, G4double xli, G4double xri, G4double eps, |
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| 386 | G4int iend, |
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| 387 | G4double aa, G4double bb, G4double cc, G4double dd, |
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| 388 | G4double rr) |
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| 389 | { |
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| 390 | G4int ier = 0; |
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| 391 | G4double xl = xli; |
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| 392 | G4double xr = xri; |
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| 393 | *x = xl; |
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| 394 | G4double tol = *x; |
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| 395 | G4double f = Fctcos(tol, aa, bb, cc, dd, rr); |
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| 396 | if (f == 0.) return ier; |
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| 397 | G4double fl, fr; |
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| 398 | fl = f; |
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| 399 | *x = xr; |
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| 400 | tol = *x; |
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| 401 | f = Fctcos(tol, aa, bb, cc, dd, rr); |
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| 402 | if (f == 0.) return ier; |
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| 403 | fr = f; |
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| 404 | |
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| 405 | // Error return in case of wrong input data |
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| 406 | if (fl*fr >= 0.) { |
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| 407 | ier = 2; |
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| 408 | return ier; |
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| 409 | } |
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| 410 | |
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| 411 | // Basic assumption fl*fr less than 0 is satisfied. |
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| 412 | // Generate tolerance for function values. |
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| 413 | G4int i = 0; |
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| 414 | G4double tolf = 100.*eps; |
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| 415 | |
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| 416 | // Start iteration loop |
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| 417 | label4: |
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| 418 | i++; |
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| 419 | |
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| 420 | // Start bisection loop |
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| 421 | for (G4int k = 1; k <= iend; k++) { |
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| 422 | *x = 0.5*(xl + xr); |
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| 423 | tol = *x; |
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| 424 | f = Fctcos(tol, aa, bb, cc, dd, rr); |
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| 425 | if (f == 0.) return 0; |
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| 426 | if (f*fr < 0.) { // Interchange xl and xr in order to get the |
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| 427 | tol = xl; // same Sign in f and fr |
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| 428 | xl = xr; |
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| 429 | xr = tol; |
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| 430 | tol = fl; |
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| 431 | fl = fr; |
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| 432 | fr = tol; |
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| 433 | } |
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| 434 | tol = f - fl; |
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| 435 | G4double a = f*tol; |
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| 436 | a = a + a; |
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| 437 | if (a < fr*(fr - fl) && i <= iend) goto label17; |
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| 438 | xr = *x; |
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| 439 | fr = f; |
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| 440 | |
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| 441 | // Test on satisfactory accuracy in bisection loop |
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| 442 | tol = eps; |
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| 443 | a = std::abs(xr); |
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| 444 | if (a > 1.) tol = tol*a; |
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| 445 | if (std::abs(xr - xl) <= tol && std::abs(fr - fl) <= tolf) goto label14; |
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| 446 | } |
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| 447 | // End of bisection loop |
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| 448 | |
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| 449 | // No convergence after iend iteration steps followed by iend |
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| 450 | // successive steps of bisection or steadily increasing function |
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| 451 | // values at right bounds. Error return. |
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| 452 | ier = 1; |
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| 453 | |
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| 454 | label14: |
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| 455 | if (std::abs(fr) > std::abs(fl)) { |
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| 456 | *x = xl; |
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| 457 | f = fl; |
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| 458 | } |
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| 459 | return ier; |
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| 460 | |
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| 461 | // Computation of iterated x-value by inverse parabolic interp |
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| 462 | label17: |
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| 463 | G4double a = fr - f; |
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| 464 | G4double dx = (*x - xl)*fl*(1. + f*(a - tol)/(a*(fr - fl)))/tol; |
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| 465 | G4double xm = *x; |
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| 466 | G4double fm = f; |
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| 467 | *x = xl - dx; |
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| 468 | tol = *x; |
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| 469 | f = Fctcos(tol, aa, bb, cc, dd, rr); |
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| 470 | if (f == 0.) return ier; |
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| 471 | |
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| 472 | // Test on satisfactory accuracy in iteration loop |
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| 473 | tol = eps; |
---|
| 474 | a = std::abs(*x); |
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| 475 | if (a > 1) tol = tol*a; |
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| 476 | if (std::abs(dx) <= tol && std::abs(f) <= tolf) return ier; |
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| 477 | |
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| 478 | // Preparation of next bisection loop |
---|
| 479 | if (f*fl < 0.) { |
---|
| 480 | xr = *x; |
---|
| 481 | fr = f; |
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| 482 | } |
---|
| 483 | else { |
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| 484 | xl = *x; |
---|
| 485 | fl = f; |
---|
| 486 | xr = xm; |
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| 487 | fr = fm; |
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| 488 | } |
---|
| 489 | goto label4; |
---|
| 490 | } |
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| 491 | |
---|
| 492 | // Test function for root-finder |
---|
| 493 | G4double |
---|
| 494 | G4HadronElastic::Fctcos(G4double t, |
---|
| 495 | G4double aa, G4double bb, G4double cc, G4double dd, |
---|
| 496 | G4double rr) |
---|
| 497 | { |
---|
| 498 | const G4double expxl = -82.; |
---|
| 499 | const G4double expxu = 82.; |
---|
| 500 | |
---|
| 501 | G4double test1 = -bb*t; |
---|
| 502 | if (test1 > expxu) test1 = expxu; |
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| 503 | if (test1 < expxl) test1 = expxl; |
---|
| 504 | |
---|
| 505 | G4double test2 = -dd*t; |
---|
| 506 | if (test2 > expxu) test2 = expxu; |
---|
| 507 | if (test2 < expxl) test2 = expxl; |
---|
| 508 | |
---|
| 509 | return aa*std::exp(test1) + cc*std::exp(test2) - rr; |
---|
| 510 | } |
---|
| 511 | |
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| 512 | |
---|