[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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| 26 | // |
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| 27 | // |
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| 28 | // original by H.P. Wellisch |
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| 29 | // modified by J.L. Chuma, TRIUMF, 19-Nov-1996 |
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| 30 | // last modified: 27-Mar-1997 |
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| 31 | // J.P.Wellisch: 23-Apr-97: minor simplifications |
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| 32 | // modified by J.L.Chuma 24-Jul-97 to set the total momentum in Cinema and |
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| 33 | // EvaporationEffects |
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| 34 | // modified by J.L.Chuma 21-Oct-97 put std::abs() around the totalE^2-mass^2 |
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| 35 | // in calculation of total momentum in |
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| 36 | // Cinema and EvaporationEffects |
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| 37 | // Chr. Volcker, 10-Nov-1997: new methods and class variables. |
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| 38 | // HPW added utilities for low energy neutron transport. (12.04.1998) |
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| 39 | // M.G. Pia, 2 Oct 1998: modified GetFermiMomentum to avoid memory leaks |
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| 40 | |
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| 41 | #include "G4Nucleus.hh" |
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| 42 | #include "G4NucleiProperties.hh" |
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| 43 | #include "Randomize.hh" |
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| 44 | #include "G4HadronicException.hh" |
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| 45 | |
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| 46 | G4Nucleus::G4Nucleus() |
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| 47 | { |
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| 48 | pnBlackTrackEnergy = 0.0; |
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| 49 | dtaBlackTrackEnergy = 0.0; |
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| 50 | pnBlackTrackEnergyfromAnnihilation = 0.0; |
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| 51 | dtaBlackTrackEnergyfromAnnihilation = 0.0; |
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| 52 | excitationEnergy = 0.0; |
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| 53 | momentum = G4ThreeVector(0.,0.,0.); |
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| 54 | fermiMomentum = 1.52*hbarc/fermi; |
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| 55 | theTemp = 293.16*kelvin; |
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| 56 | } |
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| 57 | |
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| 58 | G4Nucleus::G4Nucleus( const G4double A, const G4double Z ) |
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| 59 | { |
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| 60 | SetParameters( A, Z ); |
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| 61 | pnBlackTrackEnergy = 0.0; |
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| 62 | dtaBlackTrackEnergy = 0.0; |
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| 63 | pnBlackTrackEnergyfromAnnihilation = 0.0; |
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| 64 | dtaBlackTrackEnergyfromAnnihilation = 0.0; |
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| 65 | excitationEnergy = 0.0; |
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| 66 | momentum = G4ThreeVector(0.,0.,0.); |
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| 67 | fermiMomentum = 1.52*hbarc/fermi; |
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| 68 | theTemp = 293.16*kelvin; |
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| 69 | } |
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| 70 | |
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| 71 | G4Nucleus::G4Nucleus( const G4Material *aMaterial ) |
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| 72 | { |
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| 73 | ChooseParameters( aMaterial ); |
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| 74 | pnBlackTrackEnergy = 0.0; |
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| 75 | dtaBlackTrackEnergy = 0.0; |
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| 76 | pnBlackTrackEnergyfromAnnihilation = 0.0; |
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| 77 | dtaBlackTrackEnergyfromAnnihilation = 0.0; |
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| 78 | excitationEnergy = 0.0; |
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| 79 | momentum = G4ThreeVector(0.,0.,0.); |
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| 80 | fermiMomentum = 1.52*hbarc/fermi; |
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| 81 | theTemp = aMaterial->GetTemperature(); |
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| 82 | } |
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| 83 | |
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| 84 | G4Nucleus::~G4Nucleus() {} |
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| 85 | |
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| 86 | G4ReactionProduct G4Nucleus:: |
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| 87 | GetBiasedThermalNucleus(G4double aMass, G4ThreeVector aVelocity, G4double temp) const |
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| 88 | { |
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| 89 | G4double velMag = aVelocity.mag(); |
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| 90 | G4ReactionProduct result; |
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| 91 | G4double value = 0; |
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| 92 | G4double random = 1; |
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| 93 | G4double norm = 3.*std::sqrt(k_Boltzmann*temp*aMass*G4Neutron::Neutron()->GetPDGMass()); |
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| 94 | norm /= G4Neutron::Neutron()->GetPDGMass(); |
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| 95 | norm *= 5.; |
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| 96 | norm += velMag; |
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| 97 | norm /= velMag; |
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| 98 | while(value/norm<random) |
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| 99 | { |
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| 100 | result = GetThermalNucleus(aMass, temp); |
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| 101 | G4ThreeVector targetVelocity = 1./result.GetMass()*result.GetMomentum(); |
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| 102 | value = (targetVelocity+aVelocity).mag()/velMag; |
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| 103 | random = G4UniformRand(); |
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| 104 | } |
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| 105 | return result; |
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| 106 | } |
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| 107 | |
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| 108 | G4ReactionProduct G4Nucleus::GetThermalNucleus(G4double targetMass, G4double temp) const |
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| 109 | { |
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| 110 | G4double currentTemp = temp; |
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| 111 | if(currentTemp < 0) currentTemp = theTemp; |
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| 112 | G4ReactionProduct theTarget; |
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| 113 | theTarget.SetMass(targetMass*G4Neutron::Neutron()->GetPDGMass()); |
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| 114 | G4double px, py, pz; |
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| 115 | px = GetThermalPz(theTarget.GetMass(), currentTemp); |
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| 116 | py = GetThermalPz(theTarget.GetMass(), currentTemp); |
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| 117 | pz = GetThermalPz(theTarget.GetMass(), currentTemp); |
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| 118 | theTarget.SetMomentum(px, py, pz); |
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| 119 | G4double tMom = std::sqrt(px*px+py*py+pz*pz); |
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| 120 | G4double tEtot = std::sqrt((tMom+theTarget.GetMass())* |
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| 121 | (tMom+theTarget.GetMass())- |
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| 122 | 2.*tMom*theTarget.GetMass()); |
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| 123 | if(1-tEtot/theTarget.GetMass()>0.001) |
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| 124 | { |
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| 125 | theTarget.SetTotalEnergy(tEtot); |
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| 126 | } |
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| 127 | else |
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| 128 | { |
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| 129 | theTarget.SetKineticEnergy(tMom*tMom/(2.*theTarget.GetMass())); |
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| 130 | } |
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| 131 | return theTarget; |
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| 132 | } |
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| 133 | |
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| 134 | void |
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| 135 | G4Nucleus::ChooseParameters( const G4Material *aMaterial ) |
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| 136 | { |
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| 137 | G4double random = G4UniformRand(); |
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| 138 | G4double sum = 0; |
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| 139 | const G4ElementVector *theElementVector = aMaterial->GetElementVector(); |
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| 140 | unsigned int i; |
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| 141 | for(i=0; i<aMaterial->GetNumberOfElements(); ++i ) |
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| 142 | { |
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| 143 | sum += aMaterial->GetAtomicNumDensityVector()[i]; |
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| 144 | } |
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| 145 | G4double running = 0; |
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| 146 | for(i=0; i<aMaterial->GetNumberOfElements(); ++i ) |
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| 147 | { |
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| 148 | running += aMaterial->GetAtomicNumDensityVector()[i]; |
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| 149 | if( running/sum > random ) { |
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| 150 | aEff = (*theElementVector)[i]->GetA()*mole/g; |
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| 151 | zEff = (*theElementVector)[i]->GetZ(); |
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| 152 | break; |
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| 153 | } |
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| 154 | } |
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| 155 | } |
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| 156 | |
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| 157 | void |
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| 158 | G4Nucleus::SetParameters( const G4double A, const G4double Z ) |
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| 159 | { |
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| 160 | G4int myZ = G4int(Z + 0.5); |
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| 161 | G4int myA = G4int(A + 0.5); |
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| 162 | if( myA<1 || myZ<0 || myZ>myA ) |
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| 163 | { |
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| 164 | throw G4HadronicException(__FILE__, __LINE__, |
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| 165 | "G4Nucleus::SetParameters called with non-physical parameters"); |
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| 166 | } |
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| 167 | aEff = A; // atomic weight |
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| 168 | zEff = Z; // atomic number |
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| 169 | } |
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| 170 | |
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| 171 | G4DynamicParticle * |
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| 172 | G4Nucleus::ReturnTargetParticle() const |
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| 173 | { |
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| 174 | // choose a proton or a neutron as the target particle |
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| 175 | |
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| 176 | G4DynamicParticle *targetParticle = new G4DynamicParticle; |
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| 177 | if( G4UniformRand() < zEff/aEff ) |
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| 178 | targetParticle->SetDefinition( G4Proton::Proton() ); |
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| 179 | else |
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| 180 | targetParticle->SetDefinition( G4Neutron::Neutron() ); |
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| 181 | return targetParticle; |
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| 182 | } |
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| 183 | |
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| 184 | G4double |
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| 185 | G4Nucleus::AtomicMass( const G4double A, const G4double Z ) const |
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| 186 | { |
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| 187 | // Now returns (atomic mass - electron masses) |
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| 188 | return G4NucleiProperties::GetNuclearMass(A, Z); |
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| 189 | } |
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| 190 | |
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| 191 | G4double |
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| 192 | G4Nucleus::GetThermalPz( const G4double mass, const G4double temp ) const |
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| 193 | { |
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| 194 | G4double result = G4RandGauss::shoot(); |
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| 195 | result *= std::sqrt(k_Boltzmann*temp*mass); // Das ist impuls (Pz), |
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| 196 | // nichtrelativistische rechnung |
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| 197 | // Maxwell verteilung angenommen |
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| 198 | return result; |
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| 199 | } |
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| 200 | |
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| 201 | G4double |
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| 202 | G4Nucleus::EvaporationEffects( G4double kineticEnergy ) |
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| 203 | { |
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| 204 | // derived from original FORTRAN code EXNU by H. Fesefeldt (10-Dec-1986) |
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| 205 | // |
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| 206 | // Nuclear evaporation as function of atomic number |
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| 207 | // and kinetic energy (MeV) of primary particle |
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| 208 | // |
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| 209 | // returns kinetic energy (MeV) |
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| 210 | // |
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| 211 | if( aEff < 1.5 ) |
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| 212 | { |
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| 213 | pnBlackTrackEnergy = dtaBlackTrackEnergy = 0.0; |
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| 214 | return 0.0; |
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| 215 | } |
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| 216 | G4double ek = kineticEnergy/GeV; |
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| 217 | G4float ekin = std::min( 4.0, std::max( 0.1, ek ) ); |
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| 218 | const G4float atno = std::min( 120., aEff ); |
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| 219 | const G4float gfa = 2.0*((aEff-1.0)/70.)*std::exp(-(aEff-1.0)/70.); |
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| 220 | // |
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| 221 | // 0.35 value at 1 GeV |
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| 222 | // 0.05 value at 0.1 GeV |
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| 223 | // |
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| 224 | G4float cfa = std::max( 0.15, 0.35 + ((0.35-0.05)/2.3)*std::log(ekin) ); |
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| 225 | G4float exnu = 7.716 * cfa * std::exp(-cfa) |
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| 226 | * ((atno-1.0)/120.)*std::exp(-(atno-1.0)/120.); |
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| 227 | G4float fpdiv = std::max( 0.5, 1.0-0.25*ekin*ekin ); |
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| 228 | // |
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| 229 | // pnBlackTrackEnergy is the kinetic energy (in GeV) available for |
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| 230 | // proton/neutron black track particles |
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| 231 | // dtaBlackTrackEnergy is the kinetic energy (in GeV) available for |
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| 232 | // deuteron/triton/alpha black track particles |
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| 233 | // |
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| 234 | pnBlackTrackEnergy = exnu*fpdiv; |
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| 235 | dtaBlackTrackEnergy = exnu*(1.0-fpdiv); |
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| 236 | |
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| 237 | if( G4int(zEff+0.1) != 82 ) |
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| 238 | { |
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| 239 | G4double ran1 = -6.0; |
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| 240 | G4double ran2 = -6.0; |
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| 241 | for( G4int i=0; i<12; ++i ) |
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| 242 | { |
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| 243 | ran1 += G4UniformRand(); |
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| 244 | ran2 += G4UniformRand(); |
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| 245 | } |
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| 246 | pnBlackTrackEnergy *= 1.0 + ran1*gfa; |
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| 247 | dtaBlackTrackEnergy *= 1.0 + ran2*gfa; |
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| 248 | } |
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| 249 | pnBlackTrackEnergy = std::max( 0.0, pnBlackTrackEnergy ); |
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| 250 | dtaBlackTrackEnergy = std::max( 0.0, dtaBlackTrackEnergy ); |
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| 251 | while( pnBlackTrackEnergy+dtaBlackTrackEnergy >= ek ) |
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| 252 | { |
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| 253 | pnBlackTrackEnergy *= 1.0 - 0.5*G4UniformRand(); |
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| 254 | dtaBlackTrackEnergy *= 1.0 - 0.5*G4UniformRand(); |
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| 255 | } |
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| 256 | // G4cout << "EvaporationEffects "<<kineticEnergy<<" " |
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| 257 | // <<pnBlackTrackEnergy+dtaBlackTrackEnergy<<endl; |
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| 258 | return (pnBlackTrackEnergy+dtaBlackTrackEnergy)*GeV; |
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| 259 | } |
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| 260 | |
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| 261 | G4double G4Nucleus::AnnihilationEvaporationEffects(G4double kineticEnergy, G4double ekOrg) |
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| 262 | { |
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| 263 | // Nuclear evaporation as a function of atomic number and kinetic |
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| 264 | // energy (MeV) of primary particle. Modified for annihilation effects. |
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| 265 | // |
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| 266 | if( aEff < 1.5 || ekOrg < 0.) |
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| 267 | { |
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| 268 | pnBlackTrackEnergyfromAnnihilation = 0.0; |
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| 269 | dtaBlackTrackEnergyfromAnnihilation = 0.0; |
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| 270 | return 0.0; |
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| 271 | } |
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| 272 | G4double ek = kineticEnergy/GeV; |
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| 273 | G4float ekin = std::min( 4.0, std::max( 0.1, ek ) ); |
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| 274 | const G4float atno = std::min( 120., aEff ); |
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| 275 | const G4float gfa = 2.0*((aEff-1.0)/70.)*std::exp(-(aEff-1.0)/70.); |
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| 276 | |
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| 277 | G4float cfa = std::max( 0.15, 0.35 + ((0.35-0.05)/2.3)*std::log(ekin) ); |
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| 278 | G4float exnu = 7.716 * cfa * std::exp(-cfa) |
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| 279 | * ((atno-1.0)/120.)*std::exp(-(atno-1.0)/120.); |
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| 280 | G4float fpdiv = std::max( 0.5, 1.0-0.25*ekin*ekin ); |
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| 281 | |
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| 282 | pnBlackTrackEnergyfromAnnihilation = exnu*fpdiv; |
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| 283 | dtaBlackTrackEnergyfromAnnihilation = exnu*(1.0-fpdiv); |
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| 284 | |
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| 285 | G4double ran1 = -6.0; |
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| 286 | G4double ran2 = -6.0; |
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| 287 | for( G4int i=0; i<12; ++i ) { |
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| 288 | ran1 += G4UniformRand(); |
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| 289 | ran2 += G4UniformRand(); |
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| 290 | } |
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| 291 | pnBlackTrackEnergyfromAnnihilation *= 1.0 + ran1*gfa; |
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| 292 | dtaBlackTrackEnergyfromAnnihilation *= 1.0 + ran2*gfa; |
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| 293 | |
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| 294 | pnBlackTrackEnergyfromAnnihilation = std::max( 0.0, pnBlackTrackEnergyfromAnnihilation); |
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| 295 | dtaBlackTrackEnergyfromAnnihilation = std::max( 0.0, dtaBlackTrackEnergyfromAnnihilation); |
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| 296 | G4double blackSum = pnBlackTrackEnergyfromAnnihilation+dtaBlackTrackEnergyfromAnnihilation; |
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| 297 | if (blackSum >= ekOrg/GeV) { |
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| 298 | pnBlackTrackEnergyfromAnnihilation *= ekOrg/GeV/blackSum; |
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| 299 | dtaBlackTrackEnergyfromAnnihilation *= ekOrg/GeV/blackSum; |
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| 300 | } |
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| 301 | |
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| 302 | return (pnBlackTrackEnergyfromAnnihilation+dtaBlackTrackEnergyfromAnnihilation)*GeV; |
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| 303 | } |
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| 304 | |
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| 305 | G4double |
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| 306 | G4Nucleus::Cinema( G4double kineticEnergy ) |
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| 307 | { |
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| 308 | // derived from original FORTRAN code CINEMA by H. Fesefeldt (14-Oct-1987) |
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| 309 | // |
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| 310 | // input: kineticEnergy (MeV) |
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| 311 | // returns modified kinetic energy (MeV) |
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| 312 | // |
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| 313 | static const G4double expxu = 82.; // upper bound for arg. of exp |
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| 314 | static const G4double expxl = -expxu; // lower bound for arg. of exp |
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| 315 | |
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| 316 | G4double ek = kineticEnergy/GeV; |
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| 317 | G4double ekLog = std::log( ek ); |
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| 318 | G4double aLog = std::log( aEff ); |
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| 319 | G4double em = std::min( 1.0, 0.2390 + 0.0408*aLog*aLog ); |
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| 320 | G4double temp1 = -ek * std::min( 0.15, 0.0019*aLog*aLog*aLog ); |
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| 321 | G4double temp2 = std::exp( std::max( expxl, std::min( expxu, -(ekLog-em)*(ekLog-em)*2.0 ) ) ); |
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| 322 | G4double result = 0.0; |
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| 323 | if( std::abs( temp1 ) < 1.0 ) |
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| 324 | { |
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| 325 | if( temp2 > 1.0e-10 )result = temp1*temp2; |
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| 326 | } |
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| 327 | else result = temp1*temp2; |
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| 328 | if( result < -ek )result = -ek; |
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| 329 | return result*GeV; |
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| 330 | } |
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| 331 | |
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| 332 | // |
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| 333 | // methods for class G4Nucleus ... by Christian Volcker |
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| 334 | // |
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| 335 | |
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| 336 | G4ThreeVector G4Nucleus::GetFermiMomentum() |
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| 337 | { |
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| 338 | // chv: .. we assume zero temperature! |
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| 339 | |
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| 340 | // momentum is equally distributed in each phasespace volume dpx, dpy, dpz. |
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| 341 | G4double ranflat1= |
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| 342 | CLHEP::RandFlat::shoot((G4double)0.,(G4double)fermiMomentum); |
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| 343 | G4double ranflat2= |
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| 344 | CLHEP::RandFlat::shoot((G4double)0.,(G4double)fermiMomentum); |
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| 345 | G4double ranflat3= |
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| 346 | CLHEP::RandFlat::shoot((G4double)0.,(G4double)fermiMomentum); |
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| 347 | G4double ranmax = (ranflat1>ranflat2? ranflat1: ranflat2); |
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| 348 | ranmax = (ranmax>ranflat3? ranmax : ranflat3); |
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| 349 | |
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| 350 | // Isotropic momentum distribution |
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| 351 | G4double costheta = 2.*G4UniformRand() - 1.0; |
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| 352 | G4double sintheta = std::sqrt(1.0 - costheta*costheta); |
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| 353 | G4double phi = 2.0*pi*G4UniformRand(); |
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| 354 | |
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| 355 | G4double pz=costheta*ranmax; |
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| 356 | G4double px=sintheta*std::cos(phi)*ranmax; |
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| 357 | G4double py=sintheta*std::sin(phi)*ranmax; |
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| 358 | G4ThreeVector p(px,py,pz); |
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| 359 | return p; |
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| 360 | } |
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| 361 | |
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| 362 | G4ReactionProductVector* G4Nucleus::Fragmentate() |
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| 363 | { |
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| 364 | // needs implementation! |
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| 365 | return NULL; |
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| 366 | } |
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| 367 | |
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| 368 | void G4Nucleus::AddMomentum(const G4ThreeVector aMomentum) |
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| 369 | { |
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| 370 | momentum+=(aMomentum); |
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| 371 | } |
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| 372 | |
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| 373 | void G4Nucleus::AddExcitationEnergy( G4double anEnergy ) |
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| 374 | { |
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| 375 | excitationEnergy+=anEnergy; |
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| 376 | } |
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| 377 | |
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| 378 | /* end of file */ |
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| 379 | |
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