| Geant4 Cross Reference |
1 // 1 //
2 // ******************************************* 2 // ********************************************************************
3 // * License and Disclaimer 3 // * License and Disclaimer *
4 // * 4 // * *
5 // * The Geant4 software is copyright of th 5 // * The Geant4 software is copyright of the Copyright Holders of *
6 // * the Geant4 Collaboration. It is provided 6 // * the Geant4 Collaboration. It is provided under the terms and *
7 // * conditions of the Geant4 Software License 7 // * conditions of the Geant4 Software License, included in the file *
8 // * LICENSE and available at http://cern.ch/ 8 // * LICENSE and available at http://cern.ch/geant4/license . These *
9 // * include a list of copyright holders. 9 // * include a list of copyright holders. *
10 // * 10 // * *
11 // * Neither the authors of this software syst 11 // * Neither the authors of this software system, nor their employing *
12 // * institutes,nor the agencies providing fin 12 // * institutes,nor the agencies providing financial support for this *
13 // * work make any representation or warran 13 // * work make any representation or warranty, express or implied, *
14 // * regarding this software system or assum 14 // * regarding this software system or assume any liability for its *
15 // * use. Please see the license in the file 15 // * use. Please see the license in the file LICENSE and URL above *
16 // * for the full disclaimer and the limitatio 16 // * for the full disclaimer and the limitation of liability. *
17 // * 17 // * *
18 // * This code implementation is the result 18 // * This code implementation is the result of the scientific and *
19 // * technical work of the GEANT4 collaboratio 19 // * technical work of the GEANT4 collaboration. *
20 // * By using, copying, modifying or distri 20 // * By using, copying, modifying or distributing the software (or *
21 // * any work based on the software) you ag 21 // * any work based on the software) you agree to acknowledge its *
22 // * use in resulting scientific publicati 22 // * use in resulting scientific publications, and indicate your *
23 // * acceptance of all terms of the Geant4 Sof 23 // * acceptance of all terms of the Geant4 Software license. *
24 // ******************************************* 24 // ********************************************************************
25 // 25 //
26 // 26 //
27 /// \file GB05BOptnSplitAndKillByCrossSection. 27 /// \file GB05BOptnSplitAndKillByCrossSection.cc
28 /// \brief Implementation of the GB05BOptnSpli 28 /// \brief Implementation of the GB05BOptnSplitAndKillByCrossSection class
29 29
30 #include "GB05BOptnSplitAndKillByCrossSection. <<
31 <<
32 #include "Randomize.hh" 30 #include "Randomize.hh"
>> 31 #include "GB05BOptnSplitAndKillByCrossSection.hh"
33 32
34 //....oooOO0OOooo........oooOO0OOooo........oo 33 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
35 34
36 GB05BOptnSplitAndKillByCrossSection::GB05BOptn 35 GB05BOptnSplitAndKillByCrossSection::GB05BOptnSplitAndKillByCrossSection(G4String name)
37 : G4VBiasingOperation(name), fParticleChange << 36 : G4VBiasingOperation(name),
>> 37 fParticleChange(),
>> 38 fInteractionLength(-1.0)
38 {} 39 {}
39 40
40 //....oooOO0OOooo........oooOO0OOooo........oo 41 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
41 42
42 GB05BOptnSplitAndKillByCrossSection::~GB05BOpt << 43 GB05BOptnSplitAndKillByCrossSection::~GB05BOptnSplitAndKillByCrossSection()
>> 44 {}
43 45
44 //....oooOO0OOooo........oooOO0OOooo........oo 46 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
45 47
46 G4double GB05BOptnSplitAndKillByCrossSection:: << 48 G4double GB05BOptnSplitAndKillByCrossSection::
47 << 49 DistanceToApplyOperation( const G4Track*,
>> 50 G4double,
>> 51 G4ForceCondition* condition)
48 { 52 {
49 *condition = NotForced; 53 *condition = NotForced;
50 54
51 // -- Sample the exponential law using the t 55 // -- Sample the exponential law using the total interaction length of processes
52 // -- to couterbalance for: 56 // -- to couterbalance for:
53 G4double proposedStepLength = -std::log(G4Un << 57 G4double proposedStepLength = -std::log( G4UniformRand() ) * fInteractionLength;
54 << 58
55 return proposedStepLength; 59 return proposedStepLength;
56 } 60 }
57 61
58 //....oooOO0OOooo........oooOO0OOooo........oo 62 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
59 63
60 G4VParticleChange* << 64 G4VParticleChange*
61 GB05BOptnSplitAndKillByCrossSection::GenerateB << 65 GB05BOptnSplitAndKillByCrossSection::GenerateBiasingFinalState( const G4Track* track,
>> 66 const G4Step* )
62 { 67 {
>> 68
63 // -- This method is called if we have limit 69 // -- This method is called if we have limited the step.
64 // -- We hence make the splitting or killing 70 // -- We hence make the splitting or killing.
65 71
66 // Get track weight: 72 // Get track weight:
67 G4double initialWeight = track->GetWeight(); 73 G4double initialWeight = track->GetWeight();
68 << 74
69 // The "particle change" is the object to be 75 // The "particle change" is the object to be used to communicate to
70 // the tracking the update of the primary st 76 // the tracking the update of the primary state and/or creation
71 // secondary tracks. 77 // secondary tracks.
72 fParticleChange.Initialize(*track); 78 fParticleChange.Initialize(*track);
73 79
74 // -- Splitting and killing factors. 80 // -- Splitting and killing factors.
75 // -- They are taken the same, but the killi 81 // -- They are taken the same, but the killing factor can be make bigger.
76 G4double splittingFactor = 2.0; << 82 G4double splittingFactor = 2.0;
77 G4double killingFactor = 2.0; << 83 G4double killingFactor = 2.0;
78 84
79 if (track->GetMomentumDirection().z() > 0) { <<
80 // -- We split if the track is moving forw <<
81 85
82 // Define the tracks weight: << 86 if ( track->GetMomentumDirection().z() > 0 )
83 G4double weightOfTrack = initialWeight / s << 87 {
84 << 88 // -- We split if the track is moving forward:
85 // Ask currect track weight to be changed << 89
86 fParticleChange.ProposeParentWeight(weight << 90 // Define the tracks weight:
87 // Now make clones of this track (this is << 91 G4double weightOfTrack = initialWeight/splittingFactor;
88 // we will then have the primary and clone << 92
89 // splitting by a factor 2: << 93 // Ask currect track weight to be changed to new value:
90 G4Track* clone = new G4Track(*track); << 94 fParticleChange.ProposeParentWeight( weightOfTrack );
91 clone->SetWeight(weightOfTrack); << 95 // Now make clones of this track (this is the actual splitting):
92 fParticleChange.AddSecondary(clone); << 96 // we will then have the primary and clone of it, hence the
93 // -- Below's call added for safety & illu << 97 // splitting by a factor 2:
94 // -- modify the clone (ie : daughter) wei << 98 G4Track* clone = new G4Track( *track );
95 // -- primary. Here call not mandatory and << 99 clone->SetWeight( weightOfTrack );
96 fParticleChange.SetSecondaryWeightByProces << 100 fParticleChange.AddSecondary( clone );
97 } << 101 // -- Below's call added for safety & illustration : inform particle change to not
98 else { << 102 // -- modify the clone (ie : daughter) weight to male it that of the
99 // -- We apply Russian roulette if the tra << 103 // -- primary. Here call not mandatory and both tracks have same weights.
100 << 104 fParticleChange.SetSecondaryWeightByProcess(true);
101 // Shoot a random number (in ]0,1[ segment <<
102 G4double random = G4UniformRand(); <<
103 G4double killingProbability = 1.0 - 1.0 / <<
104 if (random < killingProbability) { <<
105 // We ask for the the track to be killed <<
106 fParticleChange.ProposeTrackStatus(fStop <<
107 } 105 }
108 else { << 106 else
109 // In this case, the track survives. We << 107 {
110 // to conserve weight among killed and s << 108 // -- We apply Russian roulette if the track is moving backward:
111 fParticleChange.ProposeParentWeight(init << 109
>> 110 // Shoot a random number (in ]0,1[ segment):
>> 111 G4double random = G4UniformRand();
>> 112 G4double killingProbability = 1.0 - 1.0/killingFactor;
>> 113 if ( random < killingProbability )
>> 114 {
>> 115 // We ask for the the track to be killed:
>> 116 fParticleChange.ProposeTrackStatus(fStopAndKill);
>> 117 }
>> 118 else
>> 119 {
>> 120 // In this case, the track survives. We change its weight
>> 121 // to conserve weight among killed and survival tracks:
>> 122 fParticleChange.ProposeParentWeight( initialWeight*killingFactor );
>> 123 }
112 } 124 }
113 } << 125
114 <<
115 return &fParticleChange; 126 return &fParticleChange;
>> 127
116 } 128 }
117 129
118 //....oooOO0OOooo........oooOO0OOooo........oo 130 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
119 131