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GB05BOptnSplitAndKillByCrossSection.cc
Go to the documentation of this file.
Or view
the newest version in sPHENIX GitHub for file GB05BOptnSplitAndKillByCrossSection.cc
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//
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// ********************************************************************
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// * License and Disclaimer *
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// * *
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// * The Geant4 software is copyright of the Copyright Holders of *
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// * the Geant4 Collaboration. It is provided under the terms and *
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// * conditions of the Geant4 Software License, included in the file *
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// * LICENSE and available at http://cern.ch/geant4/license . These *
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// * include a list of copyright holders. *
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// * *
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// * Neither the authors of this software system, nor their employing *
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// * institutes,nor the agencies providing financial support for this *
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// * work make any representation or warranty, express or implied, *
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// * regarding this software system or assume any liability for its *
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// * use. Please see the license in the file LICENSE and URL above *
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// * for the full disclaimer and the limitation of liability. *
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// * *
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// * This code implementation is the result of the scientific and *
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// * technical work of the GEANT4 collaboration. *
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// * By using, copying, modifying or distributing the software (or *
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// * any work based on the software) you agree to acknowledge its *
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// * use in resulting scientific publications, and indicate your *
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// * acceptance of all terms of the Geant4 Software license. *
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// ********************************************************************
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//
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//
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#include "
Randomize.hh
"
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#include "
GB05BOptnSplitAndKillByCrossSection.hh
"
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//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
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GB05BOptnSplitAndKillByCrossSection::GB05BOptnSplitAndKillByCrossSection
(
G4String
name
)
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:
G4VBiasingOperation
(name),
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fParticleChange(),
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fInteractionLength(-1.0)
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{}
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//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
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GB05BOptnSplitAndKillByCrossSection::~GB05BOptnSplitAndKillByCrossSection
()
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{}
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//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
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G4double
GB05BOptnSplitAndKillByCrossSection::
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DistanceToApplyOperation
(
const
G4Track
*,
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G4double
,
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G4ForceCondition
*
condition
)
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{
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*condition =
NotForced
;
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// -- Sample the exponential law using the total interaction length of processes
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// -- to couterbalance for:
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G4double
proposedStepLength = -std::log(
G4UniformRand
() ) *
fInteractionLength
;
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return
proposedStepLength;
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}
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//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
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G4VParticleChange
*
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GB05BOptnSplitAndKillByCrossSection::GenerateBiasingFinalState
(
const
G4Track
*
track
,
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const
G4Step
* )
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{
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// -- This method is called if we have limited the step.
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// -- We hence make the splitting or killing.
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// Get track weight:
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G4double
initialWeight = track->
GetWeight
();
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// The "particle change" is the object to be used to communicate to
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// the tracking the update of the primary state and/or creation
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// secondary tracks.
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fParticleChange
.
Initialize
(*track);
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// -- Splitting and killing factors.
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// -- They are taken the same, but the killing factor can be make bigger.
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G4double
splittingFactor = 2.0;
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G4double
killingFactor = 2.0;
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if
( track->
GetMomentumDirection
().
z
() > 0 )
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{
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// -- We split if the track is moving forward:
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// Define the tracks weight:
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G4double
weightOfTrack = initialWeight/splittingFactor;
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// Ask currect track weight to be changed to new value:
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fParticleChange
.
ProposeParentWeight
( weightOfTrack );
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// Now make clones of this track (this is the actual splitting):
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// we will then have the primary and clone of it, hence the
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// splitting by a factor 2:
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G4Track
* clone =
new
G4Track
( *track );
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clone->
SetWeight
( weightOfTrack );
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fParticleChange
.
AddSecondary
( clone );
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// -- Below's call added for safety & illustration : inform particle change to not
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// -- modify the clone (ie : daughter) weight to male it that of the
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// -- primary. Here call not mandatory and both tracks have same weights.
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fParticleChange
.
SetSecondaryWeightByProcess
(
true
);
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}
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else
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{
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// -- We apply Russian roulette if the track is moving backward:
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// Shoot a random number (in ]0,1[ segment):
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G4double
random =
G4UniformRand
();
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G4double
killingProbability = 1.0 - 1.0/killingFactor;
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if
( random < killingProbability )
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{
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// We ask for the the track to be killed:
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fParticleChange
.
ProposeTrackStatus
(
fStopAndKill
);
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}
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else
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{
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// In this case, the track survives. We change its weight
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// to conserve weight among killed and survival tracks:
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fParticleChange
.
ProposeParentWeight
( initialWeight*killingFactor );
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}
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}
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return
&
fParticleChange
;
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}
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//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
geant4
tree
geant4-10.6-release
examples
extended
biasing
GB05
src
GB05BOptnSplitAndKillByCrossSection.cc
Built by
Jin Huang
. updated:
Wed Jun 29 2022 17:25:02
using
1.8.2 with
ECCE GitHub integration