[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 | // G4NeutronCaptureAtRest physics process |
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| 27 | // Larry Felawka (TRIUMF), April 1998 |
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| 28 | //--------------------------------------------------------------------- |
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| 29 | |
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| 30 | #include "G4NeutronCaptureAtRest.hh" |
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| 31 | #include "G4DynamicParticle.hh" |
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| 32 | #include "G4ParticleTypes.hh" |
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| 33 | #include "Randomize.hh" |
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| 34 | #include <string.h> |
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| 35 | #include <cmath> |
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| 36 | #include <stdio.h> |
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| 37 | |
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| 38 | #define MAX_SECONDARIES 100 |
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| 39 | |
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| 40 | // constructor |
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| 41 | |
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| 42 | G4NeutronCaptureAtRest::G4NeutronCaptureAtRest(const G4String& processName, |
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| 43 | G4ProcessType aType ) : |
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| 44 | G4VRestProcess (processName, aType), // initialization |
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| 45 | massProton(G4Proton::Proton()->GetPDGMass()/GeV), |
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| 46 | massNeutron(G4Neutron::Neutron()->GetPDGMass()/GeV), |
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| 47 | massElectron(G4Electron::Electron()->GetPDGMass()/GeV), |
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| 48 | massDeuteron(G4Deuteron::Deuteron()->GetPDGMass()/GeV), |
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| 49 | massAlpha(G4Alpha::Alpha()->GetPDGMass()/GeV), |
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| 50 | pdefGamma(G4Gamma::Gamma()), |
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| 51 | pdefNeutron(G4Neutron::Neutron()) |
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| 52 | { |
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| 53 | if (verboseLevel>0) { |
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| 54 | G4cout << GetProcessName() << " is created "<< G4endl; |
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| 55 | } |
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| 56 | |
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| 57 | pv = new G4GHEKinematicsVector [MAX_SECONDARIES+1]; |
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| 58 | eve = new G4GHEKinematicsVector [MAX_SECONDARIES]; |
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| 59 | gkin = new G4GHEKinematicsVector [MAX_SECONDARIES]; |
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| 60 | |
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| 61 | } |
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| 62 | |
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| 63 | // destructor |
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| 64 | |
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| 65 | G4NeutronCaptureAtRest::~G4NeutronCaptureAtRest() |
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| 66 | { |
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| 67 | delete [] pv; |
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| 68 | delete [] eve; |
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| 69 | delete [] gkin; |
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| 70 | } |
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| 71 | |
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| 72 | |
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| 73 | // methods............................................................................. |
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| 74 | |
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| 75 | G4bool G4NeutronCaptureAtRest::IsApplicable( |
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| 76 | const G4ParticleDefinition& particle |
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| 77 | ) |
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| 78 | { |
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| 79 | return ( &particle == pdefNeutron ); |
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| 80 | |
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| 81 | } |
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| 82 | |
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| 83 | // Warning - this method may be optimized away if made "inline" |
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| 84 | G4int G4NeutronCaptureAtRest::GetNumberOfSecondaries() |
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| 85 | { |
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| 86 | return ( ngkine ); |
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| 87 | |
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| 88 | } |
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| 89 | |
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| 90 | // Warning - this method may be optimized away if made "inline" |
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| 91 | G4GHEKinematicsVector* G4NeutronCaptureAtRest::GetSecondaryKinematics() |
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| 92 | { |
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| 93 | return ( &gkin[0] ); |
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| 94 | |
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| 95 | } |
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| 96 | |
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| 97 | G4double G4NeutronCaptureAtRest::AtRestGetPhysicalInteractionLength( |
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| 98 | const G4Track& track, |
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| 99 | G4ForceCondition* condition |
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| 100 | ) |
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| 101 | { |
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| 102 | // beggining of tracking |
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| 103 | ResetNumberOfInteractionLengthLeft(); |
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| 104 | |
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| 105 | // condition is set to "Not Forced" |
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| 106 | *condition = NotForced; |
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| 107 | |
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| 108 | // get mean life time |
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| 109 | currentInteractionLength = GetMeanLifeTime(track, condition); |
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| 110 | |
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| 111 | if ((currentInteractionLength <0.0) || (verboseLevel>2)){ |
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| 112 | G4cout << "G4NeutronCaptureAtRestProcess::AtRestGetPhysicalInteractionLength "; |
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| 113 | G4cout << "[ " << GetProcessName() << "]" <<G4endl; |
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| 114 | track.GetDynamicParticle()->DumpInfo(); |
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| 115 | G4cout << " in Material " << track.GetMaterial()->GetName() <<G4endl; |
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| 116 | G4cout << "MeanLifeTime = " << currentInteractionLength/ns << "[ns]" <<G4endl; |
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| 117 | } |
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| 118 | |
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| 119 | return theNumberOfInteractionLengthLeft * currentInteractionLength; |
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| 120 | |
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| 121 | } |
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| 122 | |
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| 123 | G4VParticleChange* G4NeutronCaptureAtRest::AtRestDoIt( |
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| 124 | const G4Track& track, |
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| 125 | const G4Step& |
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| 126 | ) |
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| 127 | // |
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| 128 | // Handles Neutrons at rest; a Neutron can either create secondaries or |
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| 129 | // do nothing (in which case it should be sent back to decay-handling |
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| 130 | // section |
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| 131 | // |
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| 132 | { |
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| 133 | |
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| 134 | // Initialize ParticleChange |
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| 135 | // all members of G4VParticleChange are set to equal to |
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| 136 | // corresponding member in G4Track |
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| 137 | |
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| 138 | aParticleChange.Initialize(track); |
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| 139 | |
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| 140 | // Store some global quantities that depend on current material and particle |
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| 141 | |
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| 142 | globalTime = track.GetGlobalTime()/s; |
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| 143 | G4Material * aMaterial = track.GetMaterial(); |
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| 144 | const G4int numberOfElements = aMaterial->GetNumberOfElements(); |
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| 145 | const G4ElementVector* theElementVector = aMaterial->GetElementVector(); |
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| 146 | |
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| 147 | const G4double* theAtomicNumberDensity = aMaterial->GetAtomicNumDensityVector(); |
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| 148 | G4double normalization = 0; |
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| 149 | for ( G4int i1=0; i1 < numberOfElements; i1++ ) |
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| 150 | { |
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| 151 | normalization += theAtomicNumberDensity[i1] ; // change when nucleon specific |
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| 152 | // probabilities are included. |
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| 153 | } |
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| 154 | G4double runningSum= 0.; |
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| 155 | G4double random = G4UniformRand()*normalization; |
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| 156 | for ( G4int i2=0; i2 < numberOfElements; i2++ ) |
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| 157 | { |
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| 158 | runningSum += theAtomicNumberDensity[i2]; // change when nucleon specific |
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| 159 | // probabilities are included. |
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| 160 | if (random<=runningSum) |
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| 161 | { |
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| 162 | targetCharge = G4double((*theElementVector)[i2]->GetZ()); |
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| 163 | targetAtomicMass = (*theElementVector)[i2]->GetN(); |
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| 164 | } |
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| 165 | } |
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| 166 | if (random>runningSum) |
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| 167 | { |
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| 168 | targetCharge = G4double((*theElementVector)[numberOfElements-1]->GetZ()); |
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| 169 | targetAtomicMass = (*theElementVector)[numberOfElements-1]->GetN(); |
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| 170 | |
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| 171 | } |
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| 172 | |
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| 173 | if (verboseLevel>1) { |
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| 174 | G4cout << "G4NeutronCaptureAtRest::AtRestDoIt is invoked " <<G4endl; |
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| 175 | } |
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| 176 | |
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| 177 | G4ParticleMomentum momentum; |
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| 178 | G4float localtime; |
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| 179 | |
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| 180 | G4ThreeVector position = track.GetPosition(); |
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| 181 | |
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| 182 | GenerateSecondaries(); // Generate secondaries |
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| 183 | |
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| 184 | aParticleChange.SetNumberOfSecondaries( ngkine ); |
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| 185 | |
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| 186 | for ( G4int isec = 0; isec < ngkine; isec++ ) { |
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| 187 | G4DynamicParticle* aNewParticle = new G4DynamicParticle; |
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| 188 | aNewParticle->SetDefinition( gkin[isec].GetParticleDef() ); |
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| 189 | aNewParticle->SetMomentum( gkin[isec].GetMomentum() * GeV ); |
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| 190 | |
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| 191 | localtime = globalTime + gkin[isec].GetTOF(); |
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| 192 | |
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| 193 | G4Track* aNewTrack = new G4Track( aNewParticle, localtime*s, position ); |
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| 194 | aNewTrack->SetTouchableHandle(track.GetTouchableHandle()); |
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| 195 | aParticleChange.AddSecondary( aNewTrack ); |
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| 196 | |
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| 197 | } |
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| 198 | |
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| 199 | aParticleChange.ProposeLocalEnergyDeposit( 0.0*GeV ); |
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| 200 | |
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| 201 | aParticleChange.ProposeTrackStatus(fStopAndKill); // Kill the incident Neutron |
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| 202 | |
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| 203 | // clear InteractionLengthLeft |
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| 204 | |
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| 205 | ResetNumberOfInteractionLengthLeft(); |
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| 206 | |
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| 207 | return &aParticleChange; |
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| 208 | |
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| 209 | } |
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| 210 | |
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| 211 | |
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| 212 | void G4NeutronCaptureAtRest::GenerateSecondaries() |
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| 213 | { |
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| 214 | static G4int index; |
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| 215 | static G4int l; |
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| 216 | static G4int nopt; |
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| 217 | static G4int i; |
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| 218 | static G4ParticleDefinition* jnd; |
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| 219 | |
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| 220 | for (i = 1; i <= MAX_SECONDARIES; ++i) { |
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| 221 | pv[i].SetZero(); |
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| 222 | } |
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| 223 | |
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| 224 | ngkine = 0; // number of generated secondary particles |
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| 225 | ntot = 0; |
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| 226 | result.SetZero(); |
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| 227 | result.SetMass( massNeutron ); |
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| 228 | result.SetKineticEnergyAndUpdate( 0. ); |
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| 229 | result.SetTOF( 0. ); |
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| 230 | result.SetParticleDef( pdefNeutron ); |
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| 231 | |
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| 232 | NeutronCapture(&nopt); |
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| 233 | |
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| 234 | // *** CHECK WHETHER THERE ARE NEW PARTICLES GENERATED *** |
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| 235 | if (ntot != 0 || result.GetParticleDef() != pdefNeutron) { |
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| 236 | // *** CURRENT PARTICLE IS NOT THE SAME AS IN THE BEGINNING OR/AND *** |
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| 237 | // *** ONE OR MORE SECONDARIES HAVE BEEN GENERATED *** |
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| 238 | |
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| 239 | // --- INITIAL PARTICLE TYPE HAS BEEN CHANGED ==> PUT NEW TYPE ON --- |
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| 240 | // --- THE GEANT TEMPORARY STACK --- |
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| 241 | |
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| 242 | // --- PUT PARTICLE ON THE STACK --- |
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| 243 | gkin[0] = result; |
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| 244 | gkin[0].SetTOF( result.GetTOF() * 5e-11 ); |
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| 245 | ngkine = 1; |
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| 246 | |
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| 247 | // --- ALL QUANTITIES ARE TAKEN FROM THE GHEISHA STACK WHERE THE --- |
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| 248 | // --- CONVENTION IS THE FOLLOWING --- |
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| 249 | |
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| 250 | // --- ONE OR MORE SECONDARIES HAVE BEEN GENERATED --- |
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| 251 | for (l = 1; l <= ntot; ++l) { |
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| 252 | index = l - 1; |
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| 253 | jnd = eve[index].GetParticleDef(); |
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| 254 | |
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| 255 | // --- ADD PARTICLE TO THE STACK IF STACK NOT YET FULL --- |
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| 256 | if (ngkine < MAX_SECONDARIES) { |
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| 257 | gkin[ngkine] = eve[index]; |
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| 258 | gkin[ngkine].SetTOF( eve[index].GetTOF() * 5e-11 ); |
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| 259 | ++ngkine; |
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| 260 | } |
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| 261 | } |
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| 262 | } |
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| 263 | else { |
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| 264 | // --- NO SECONDARIES GENERATED AND PARTICLE IS STILL THE SAME --- |
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| 265 | // --- ==> COPY EVERYTHING BACK IN THE CURRENT GEANT STACK --- |
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| 266 | ngkine = 0; |
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| 267 | ntot = 0; |
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| 268 | globalTime += result.GetTOF() * G4float(5e-11); |
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| 269 | } |
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| 270 | |
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| 271 | // --- LIMIT THE VALUE OF NGKINE IN CASE OF OVERFLOW --- |
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| 272 | ngkine = G4int(std::min(ngkine,G4int(MAX_SECONDARIES))); |
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| 273 | |
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| 274 | } // GenerateSecondaries |
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| 275 | |
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| 276 | |
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| 277 | void G4NeutronCaptureAtRest::Normal(G4float *ran) |
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| 278 | { |
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| 279 | static G4int i; |
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| 280 | |
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| 281 | // *** NVE 14-APR-1988 CERN GENEVA *** |
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| 282 | // ORIGIN : H.FESEFELDT (27-OCT-1983) |
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| 283 | |
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| 284 | *ran = G4float(-6.); |
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| 285 | for (i = 1; i <= 12; ++i) { |
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| 286 | *ran += G4UniformRand(); |
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| 287 | } |
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| 288 | |
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| 289 | } // Normal |
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| 290 | |
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| 291 | |
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| 292 | void G4NeutronCaptureAtRest::NeutronCapture(G4int *nopt) |
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| 293 | { |
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| 294 | static G4int nt; |
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| 295 | static G4float xp, pcm; |
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| 296 | static G4float ran; |
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| 297 | |
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| 298 | // *** ROUTINE FOR CAPTURE OF NEUTRAL BARYONS *** |
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| 299 | // *** NVE 04-MAR-1988 CERN GENEVA *** |
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| 300 | // ORIGIN : H.FESEFELDT (02-DEC-1986) |
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| 301 | |
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| 302 | *nopt = 1; |
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| 303 | pv[1] = result; |
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| 304 | pv[2].SetZero(); |
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| 305 | pv[2].SetMass( AtomAs(targetAtomicMass, targetCharge) ); |
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| 306 | pv[2].SetMomentumAndUpdate( 0., 0., 0. ); |
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| 307 | pv[2].SetTOF( result.GetTOF() ); |
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| 308 | pv[2].SetParticleDef( NULL ); |
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| 309 | pv[MAX_SECONDARIES].Add( pv[1], pv[2] ); |
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| 310 | pv[MAX_SECONDARIES].SetMomentum( -pv[MAX_SECONDARIES].GetMomentum().x(), -pv[MAX_SECONDARIES].GetMomentum().y(), -pv[MAX_SECONDARIES].GetMomentum().z() ); |
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| 311 | pv[MAX_SECONDARIES].SetParticleDef( NULL ); |
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| 312 | Normal(&ran); |
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| 313 | pcm = ran * G4float(.001) + G4float(.0065); |
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| 314 | ran = G4UniformRand(); |
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| 315 | result.SetTOF( result.GetTOF() - std::log(ran) * G4float(480.) ); |
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| 316 | pv[3].SetZero(); |
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| 317 | pv[3].SetMass( 0. ); |
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| 318 | pv[3].SetKineticEnergyAndUpdate( pcm ); |
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| 319 | pv[3].SetTOF( result.GetTOF() ); |
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| 320 | pv[3].SetParticleDef( pdefGamma ); |
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| 321 | pv[3].Lor( pv[3], pv[MAX_SECONDARIES] ); |
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| 322 | nt = 3; |
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| 323 | xp = G4float(.008) - pcm; |
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| 324 | if (xp >= G4float(0.)) { |
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| 325 | nt = 4; |
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| 326 | pv[4].SetZero(); |
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| 327 | pv[4].SetMass( 0. ); |
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| 328 | pv[4].SetKineticEnergyAndUpdate( xp ); |
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| 329 | pv[4].SetTOF( result.GetTOF() ); |
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| 330 | pv[4].SetParticleDef( pdefGamma ); |
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| 331 | pv[4].Lor( pv[4], pv[MAX_SECONDARIES] ); |
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| 332 | } |
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| 333 | result = pv[3]; |
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| 334 | if (nt == 4) { |
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| 335 | if (ntot < MAX_SECONDARIES-1) { |
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| 336 | eve[ntot++] = pv[4]; |
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| 337 | } |
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| 338 | } |
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| 339 | |
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| 340 | } // NeutronCapture |
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| 341 | |
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| 342 | |
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| 343 | G4double G4NeutronCaptureAtRest::AtomAs(G4float a, G4float z) |
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| 344 | { |
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| 345 | G4float ret_val; |
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| 346 | G4double d__1, d__2; |
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| 347 | |
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| 348 | static G4double aa; |
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| 349 | static G4int ia, iz; |
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| 350 | static G4double zz; |
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| 351 | static G4float rma, rmd; |
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| 352 | static G4int ipp; |
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| 353 | static G4float rmn, rmp; |
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| 354 | static G4int izz; |
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| 355 | static G4float rmel; |
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| 356 | static G4double mass; |
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| 357 | |
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| 358 | // *** DETERMINATION OF THE ATOMIC MASS *** |
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| 359 | // *** NVE 19-MAY-1988 CERN GENEVA *** |
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| 360 | // ORIGIN : H.FESEFELDT (02-DEC-1986) |
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| 361 | |
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| 362 | // --- GET ATOMIC (= ELECTRONS INCL.) MASSES (IN MEV) FROM RMASS ARRAY --- |
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| 363 | // --- ELECTRON --- |
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| 364 | rmel = massElectron * G4float(1e3); |
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| 365 | // --- PROTON --- |
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| 366 | rmp = massProton * G4float(1e3); |
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| 367 | // --- NEUTRON --- |
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| 368 | rmn = massNeutron * G4float(1e3); |
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| 369 | // --- DEUTERON --- |
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| 370 | rmd = massDeuteron * G4float(1e3) + rmel; |
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| 371 | // --- ALPHA --- |
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| 372 | rma = massAlpha * G4float(1e3) + rmel * G4float(2.); |
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| 373 | |
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| 374 | ret_val = G4float(0.); |
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| 375 | aa = a * 1.; |
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| 376 | zz = z * 1.; |
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| 377 | ia = G4int(a + G4float(.5)); |
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| 378 | if (ia < 1) { |
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| 379 | return ret_val; |
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| 380 | } |
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| 381 | iz = G4int(z + G4float(.5)); |
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| 382 | if (iz < 0 || iz > ia) { |
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| 383 | return ret_val; |
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| 384 | } |
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| 385 | mass = 0.; |
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| 386 | if (ia == 1) { |
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| 387 | if (iz == 0) { |
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| 388 | mass = rmn; |
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| 389 | } |
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| 390 | else if (iz == 1) { |
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| 391 | mass = rmp + rmel; |
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| 392 | } |
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| 393 | } |
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| 394 | else if (ia == 2 && iz == 1) { |
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| 395 | mass = rmd; |
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| 396 | } |
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| 397 | else if (ia == 4 && iz == 2) { |
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| 398 | mass = rma; |
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| 399 | } |
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| 400 | else if ( (ia == 2 && iz != 1) || ia == 3 || (ia == 4 && iz != 2) || ia > 4) { |
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| 401 | d__1 = aa / G4float(2.) - zz; |
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| 402 | d__2 = zz; |
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| 403 | mass = (aa - zz) * rmn + zz * rmp + zz * rmel - aa * G4float(15.67) + |
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| 404 | std::pow(aa, .6666667) * G4float(17.23) + d__1 * d__1 * G4float(93.15) / aa + |
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| 405 | d__2 * d__2 * G4float(.6984523) / std::pow(aa, .3333333); |
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| 406 | ipp = (ia - iz) % 2; |
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| 407 | izz = iz % 2; |
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| 408 | if (ipp == izz) { |
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| 409 | mass += (ipp + izz - 1) * G4float(12.) * std::pow(aa, -.5); |
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| 410 | } |
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| 411 | } |
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| 412 | ret_val = mass * G4float(.001); |
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| 413 | return ret_val; |
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| 414 | |
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| 415 | } // AtomAs |
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