[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 | #include "G4Absorber.hh" |
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| 27 | #include "G4KineticTrack.hh" |
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| 28 | #include "G4PionPlus.hh" |
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| 29 | #include "G4PionMinus.hh" |
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| 30 | #include "G4PionZero.hh" |
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| 31 | #include "G4Proton.hh" |
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| 32 | #include "G4Neutron.hh" |
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| 33 | |
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| 34 | #include "G4LorentzRotation.hh" |
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| 35 | |
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| 36 | G4Absorber::G4Absorber(G4double cutOnP) |
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| 37 | { |
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| 38 | theCutOnP = cutOnP; |
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| 39 | theAbsorbers = new G4KineticTrackVector; |
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| 40 | theProducts = new G4KineticTrackVector; |
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| 41 | } |
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| 42 | |
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| 43 | |
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| 44 | G4Absorber::~G4Absorber() |
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| 45 | { |
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| 46 | delete theAbsorbers; |
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| 47 | delete theProducts; |
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| 48 | } |
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| 49 | |
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| 50 | |
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| 51 | bool G4Absorber::WillBeAbsorbed(const G4KineticTrack & kt) |
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| 52 | { |
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| 53 | // FixMe: actually only for pions |
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| 54 | // if(kt.Get4Momentum().vect().mag() < theCutOnP) |
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| 55 | // Cut on kinetic Energy... |
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| 56 | if (kt.Get4Momentum().e() - kt.GetActualMass() < theCutOnP) |
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| 57 | { |
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[1196] | 58 | if(kt.GetDefinition() == G4PionPlus::PionPlus() || |
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| 59 | kt.GetDefinition() == G4PionZero::PionZero() || |
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[819] | 60 | kt.GetDefinition() == G4PionMinus::PionMinus()) |
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| 61 | { |
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| 62 | return true; |
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| 63 | } |
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| 64 | } |
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| 65 | return false; |
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| 66 | } |
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| 67 | |
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| 68 | |
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| 69 | |
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| 70 | G4bool G4Absorber::Absorb(G4KineticTrack & kt, G4KineticTrackVector & tgt) |
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| 71 | { |
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| 72 | if(!FindAbsorbers(kt, tgt)) |
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| 73 | return false; |
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| 74 | return FindProducts(kt); |
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| 75 | } |
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| 76 | |
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| 77 | |
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| 78 | G4bool G4Absorber::FindAbsorbers(G4KineticTrack & kt, |
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| 79 | G4KineticTrackVector & tgt) |
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| 80 | { |
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| 81 | G4KineticTrack * kt1 = NULL; |
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| 82 | G4KineticTrack * kt2 = NULL; |
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| 83 | G4double dist1 = DBL_MAX; |
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| 84 | G4double dist2 = DBL_MAX; |
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| 85 | G4double charge1 = 0; |
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| 86 | G4double charge2 = 0; |
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| 87 | G4double charge0 = kt.GetDefinition()->GetPDGCharge(); |
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| 88 | G4ThreeVector pos = kt.GetPosition(); |
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| 89 | |
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| 90 | std::vector<G4KineticTrack *>::iterator iter; |
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| 91 | for(iter = tgt.begin(); iter != tgt.end(); ++iter) |
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| 92 | { |
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| 93 | G4KineticTrack * curr = *iter; |
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| 94 | G4double dist = (pos-curr->GetPosition()).mag(); |
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| 95 | if(dist >= dist2) |
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| 96 | continue; |
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| 97 | if(dist < dist1) |
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| 98 | { |
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| 99 | if(dist1 == DBL_MAX) // accept the candidate |
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| 100 | { |
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| 101 | kt1 = curr; |
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| 102 | charge1 = kt1->GetDefinition()->GetPDGCharge(); |
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| 103 | dist1 = dist; |
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| 104 | continue; |
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| 105 | } |
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| 106 | if(dist2 == DBL_MAX) // accept the candidate put kt1 in kt2 |
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| 107 | { |
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| 108 | kt2 = kt1; |
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| 109 | charge2 = charge1; |
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| 110 | dist2 = dist1; |
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| 111 | kt1 = curr; |
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| 112 | charge1 = kt1->GetDefinition()->GetPDGCharge(); |
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| 113 | dist1 = dist; |
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| 114 | continue; |
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| 115 | } |
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| 116 | // test the compatibility with charge conservation |
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| 117 | G4double charge = curr->GetDefinition()->GetPDGCharge(); |
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| 118 | if((charge0+charge1+charge < 0.) || |
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| 119 | (charge0+charge1+charge) > 2*eplus) |
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| 120 | { // incomatible: change kt1 with curr. |
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| 121 | kt1 = curr; |
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| 122 | charge1 = charge; |
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| 123 | dist1 = dist; |
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| 124 | } |
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| 125 | else |
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| 126 | { // compatible: change kt1 with curr and kt2 with kt1 |
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| 127 | kt2 = kt1; |
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| 128 | charge2 = charge1; |
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| 129 | dist2 = dist1; |
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| 130 | kt1 = curr; |
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| 131 | charge1 = charge; |
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| 132 | dist1 = dist; |
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| 133 | } |
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| 134 | continue; |
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| 135 | } |
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| 136 | // here if dist1 < dist < dist2 |
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| 137 | if(dist2 == DBL_MAX) // accept the candidate |
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| 138 | { |
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| 139 | kt2 = curr; |
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| 140 | charge2 = kt2->GetDefinition()->GetPDGCharge(); |
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| 141 | dist2 = dist; |
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| 142 | continue; |
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| 143 | } |
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| 144 | // test the compatibility with charge conservation |
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| 145 | G4double charge = curr->GetDefinition()->GetPDGCharge(); |
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| 146 | if((charge0+charge1+charge < 0.) || |
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| 147 | (charge0+charge1+charge) > 2*eplus) |
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| 148 | continue; // incomatible: do nothing |
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| 149 | // compatible: change kt2 with curr |
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| 150 | kt2 = curr; |
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| 151 | charge2 = charge; |
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| 152 | dist2 = dist; |
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| 153 | } |
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| 154 | |
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| 155 | theAbsorbers->clear(); // do not delete tracks in theAbsorbers vector! |
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| 156 | if((kt1 == NULL) || (kt2 == NULL)) |
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| 157 | return false; |
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| 158 | |
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| 159 | theAbsorbers->push_back(kt1); |
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| 160 | theAbsorbers->push_back(kt2); |
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| 161 | return true; |
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| 162 | } |
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| 163 | |
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| 164 | |
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| 165 | |
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| 166 | G4bool G4Absorber::FindProducts(G4KineticTrack & kt) |
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| 167 | { |
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| 168 | // Choose the products type |
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| 169 | G4ParticleDefinition * prod1; |
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| 170 | G4ParticleDefinition * prod2; |
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| 171 | G4KineticTrack * abs1 = (*theAbsorbers)[0]; |
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| 172 | G4KineticTrack * abs2 = (*theAbsorbers)[1]; |
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| 173 | |
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| 174 | G4double charge = kt.GetDefinition()->GetPDGCharge(); |
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| 175 | if(charge == eplus) |
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| 176 | { // a neutron become proton |
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| 177 | prod1 = G4Proton::Proton(); |
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| 178 | if(abs1->GetDefinition() == G4Neutron::Neutron()) |
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| 179 | prod2 = abs2->GetDefinition(); |
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| 180 | else |
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| 181 | prod2 = G4Proton::Proton(); |
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| 182 | } |
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| 183 | else if(charge == -eplus) |
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| 184 | { // a proton become neutron |
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| 185 | prod1 = G4Neutron::Neutron(); |
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| 186 | if(abs1->GetDefinition() == G4Proton::Proton()) |
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| 187 | prod2 = abs2->GetDefinition(); |
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| 188 | else |
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| 189 | prod2 = G4Neutron::Neutron(); |
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| 190 | } |
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| 191 | else // charge = 0: leave particle types unchenged |
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| 192 | { |
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| 193 | prod1 = abs1->GetDefinition(); |
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| 194 | prod2 = abs2->GetDefinition(); |
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| 195 | } |
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| 196 | |
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| 197 | // Translate to the CMS frame |
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| 198 | G4LorentzVector momLab = kt.Get4Momentum()+abs1->Get4Momentum()+ |
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| 199 | abs2->Get4Momentum(); |
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| 200 | G4LorentzRotation toCMSFrame((-1)*momLab.boostVector()); |
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| 201 | G4LorentzRotation toLabFrame(momLab.boostVector()); |
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| 202 | G4LorentzVector momCMS = toCMSFrame*momLab; |
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| 203 | |
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| 204 | // Evaluate the final momentum of products |
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| 205 | G4double m1 = prod1->GetPDGMass(); |
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| 206 | G4double m2 = prod2->GetPDGMass(); |
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| 207 | G4double e0 = momCMS.e(); |
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| 208 | G4double squareP = (e0*e0*e0*e0-2*e0*e0*(m1*m1+m2*m2)+ |
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| 209 | (m2*m2-m1*m1)*(m2*m2-m1*m1))/(4*e0*e0); |
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| 210 | // if(squareP < 0) // should never happen |
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| 211 | // squareP = 0; |
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| 212 | G4ThreeVector mom1CMS = GetRandomDirection(); |
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| 213 | mom1CMS = std::sqrt(squareP)*mom1CMS; |
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| 214 | G4LorentzVector final4Mom1CMS(mom1CMS, std::sqrt(squareP+m1*m1)); |
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| 215 | G4LorentzVector final4Mom2CMS((-1)*mom1CMS, std::sqrt(squareP+m2*m2)); |
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| 216 | |
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| 217 | // Go back to the lab frame |
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| 218 | G4LorentzVector mom1 = toLabFrame*final4Mom1CMS; |
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| 219 | G4LorentzVector mom2 = toLabFrame*final4Mom2CMS; |
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| 220 | |
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| 221 | // ------ debug |
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| 222 | /* |
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| 223 | G4LorentzVector temp = mom1+mom2; |
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| 224 | |
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| 225 | cout << (1/MeV)*momLab.x() << " " << (1/MeV)*momLab.y() << " " |
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| 226 | << (1/MeV)*momLab.z() << " " << (1/MeV)*momLab.t() << " " |
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| 227 | << (1/MeV)*momLab.vect().mag() << " " << (1/MeV)*momLab.mag() << " " |
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| 228 | << (1/MeV)*temp.x() << " " << (1/MeV)*temp.y() << " " |
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| 229 | << (1/MeV)*temp.z() << " " << (1/MeV)*temp.t() << " " |
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| 230 | << (1/MeV)*temp.vect().mag() << " " << (1/MeV)*temp.mag() << " " |
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| 231 | << (1/MeV)*std::sqrt(squareP) << endl; |
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| 232 | |
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| 233 | */ |
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| 234 | // ------ end debug |
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| 235 | |
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| 236 | // Build two new kinetic tracks and add to products |
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| 237 | G4KineticTrack * kt1 = new G4KineticTrack(prod1, 0., abs1->GetPosition(), |
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| 238 | mom1); |
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| 239 | G4KineticTrack * kt2 = new G4KineticTrack(prod2, 0., abs2->GetPosition(), |
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| 240 | mom2); |
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| 241 | // ------ debug |
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| 242 | /* |
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| 243 | G4LorentzVector initialMom1 = abs1->Get4Momentum(); |
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| 244 | G4LorentzVector initialMom2 = abs2->Get4Momentum(); |
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| 245 | G4LorentzVector pion4MomCMS = toCMSFrame*kt.Get4Momentum(); |
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| 246 | cout << (1/MeV)*initialMom1.x() << " " << (1/MeV)*initialMom1.y() << " " |
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| 247 | << (1/MeV)*initialMom1.z() << " " << (1/MeV)*initialMom1.e() << " " |
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| 248 | << (1/MeV)*initialMom1.vect().mag() << " " |
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| 249 | << (1/MeV)*initialMom2.x() << " " << (1/MeV)*initialMom2.y() << " " |
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| 250 | << (1/MeV)*initialMom2.z() << " " << (1/MeV)*initialMom2.e() << " " |
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| 251 | << (1/MeV)*initialMom2.vect().mag() << " " |
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| 252 | << (1/MeV)*mom1.x() << " " << (1/MeV)*mom1.y() << " " |
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| 253 | << (1/MeV)*mom1.z() << " " << (1/MeV)*mom1.e() << " " |
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| 254 | << (1/MeV)*mom1.vect().mag() << " " |
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| 255 | << (1/MeV)*mom2.x() << " " << (1/MeV)*mom2.y() << " " |
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| 256 | << (1/MeV)*mom2.z() << " " << (1/MeV)*mom2.e() << " " |
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| 257 | << (1/MeV)*mom2.vect().mag() << " " |
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| 258 | << (1/MeV)*pion4MomCMS.x() << " " << (1/MeV)*pion4MomCMS.y() << " " |
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| 259 | << (1/MeV)*pion4MomCMS.z() << " " << (1/MeV)*pion4MomCMS.e() << " " |
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| 260 | << (1/MeV)*pion4MomCMS.vect().mag() << " " |
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| 261 | << (1/MeV)*final4Mom1CMS.x() << " " << (1/MeV)*final4Mom1CMS.y() << " " |
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| 262 | << (1/MeV)*final4Mom1CMS.z() << " " << (1/MeV)*final4Mom1CMS.e() << " " |
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| 263 | << (1/MeV)*final4Mom1CMS.vect().mag() << " " |
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| 264 | << (1/MeV)*final4Mom2CMS.x() << " " << (1/MeV)*final4Mom2CMS.y() << " " |
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| 265 | << (1/MeV)*final4Mom2CMS.z() << " " << (1/MeV)*final4Mom2CMS.e() << " " |
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| 266 | << (1/MeV)*final4Mom2CMS.vect().mag() << endl; |
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| 267 | */ |
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| 268 | // ------ end debug |
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| 269 | |
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| 270 | theProducts->clear(); |
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| 271 | theProducts->push_back(kt1); |
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| 272 | theProducts->push_back(kt2); |
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| 273 | return true; |
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| 274 | } |
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| 275 | |
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| 276 | |
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| 277 | |
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| 278 | G4ThreeVector G4Absorber::GetRandomDirection() |
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| 279 | { |
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| 280 | G4double theta = 2.0*G4UniformRand()-1.0; |
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| 281 | theta = std::acos(theta); |
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| 282 | G4double phi = G4UniformRand()*2*pi; |
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| 283 | G4ThreeVector direction(std::sin(theta)*std::cos(phi), std::sin(theta)*std::sin(phi), std::cos(theta)); |
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| 284 | return direction; |
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| 285 | } |
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| 286 | |
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| 287 | |
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| 288 | |
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| 289 | |
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| 290 | |
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| 291 | |
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| 292 | |
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