Gabriele Cosmo
101 lines
4.8 KiB
C++
101 lines
4.8 KiB
C++
//
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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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// G4BOptnLeadingParticle
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//
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// Class Description:
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//
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// A G4VBiasingOperation that implements the so-called "Leading
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// particle biasing scheme". It is of interest in the shield problem
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// to estimate the flux leaking from the shield.
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// It works as follows:
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// - it is intented for hadronic inelastic interaction
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// - at each interaction, are kept:
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// - the most energetic particle (the leading particle)
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// - with unmodified weight
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// - randomly one particle of each species
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// - with this particle weight = n * primary_weight where
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// n is the number of particles of this species
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//
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// Author: Marc Verderi, November 2019.
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// --------------------------------------------------------------------
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#ifndef G4BOptnLeadingParticle_hh
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#define G4BOptnLeadingParticle_hh 1
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#include "G4VBiasingOperation.hh"
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#include "G4ParticleChange.hh"
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class G4BOptnLeadingParticle : public G4VBiasingOperation
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{
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public:
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// -- Constructor :
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G4BOptnLeadingParticle(const G4String& name);
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// -- destructor:
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virtual ~G4BOptnLeadingParticle();
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// -- Methods from G4VBiasingOperation interface:
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// ----------------------------------------------
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// -- Unused:
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virtual const G4VBiasingInteractionLaw*
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ProvideOccurenceBiasingInteractionLaw( const G4BiasingProcessInterface*,
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G4ForceCondition& ) { return nullptr; }
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// -- Used:
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virtual G4VParticleChange*
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ApplyFinalStateBiasing( const G4BiasingProcessInterface*, // -- Method used for this biasing. The related biasing operator
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const G4Track*, // -- returns this biasing operation at the post step do it level
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const G4Step*, // -- when the wrapped process has won the interaction length race.
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G4bool& ); // -- The wrapped process final state is then trimmed.
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// -- Unused:
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virtual G4double
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DistanceToApplyOperation( const G4Track*, G4double, G4ForceCondition* ) { return 0.0; }
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virtual G4VParticleChange*
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GenerateBiasingFinalState( const G4Track*, const G4Step* ) { return nullptr; }
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// -- The possibility is given to further apply a Russian roulette on tracks that are accompagnying the leading particle
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// -- after the classical leading particle biasing algorithm has been applied.
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// -- This is of interest when applying the technique to e+ -> gamma gamma for example. Given one gamma is leading,
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// -- the second one is alone in its category, hence selected. With the Russian roulette it is then possible to keep
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// -- this one randomly. This is also of interest for pi0 decays, or for brem. e- -> e- gamma where the e- or gamma
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// -- are alone in their category.
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void SetFurtherKillingProbability( G4double p ) // -- if p <= 0.0 the killing is ignored.
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{
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fRussianRouletteKillingProbability = p;
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}
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G4double GetFurtherKillingProbability() const
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{
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return fRussianRouletteKillingProbability;
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}
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private:
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// -- Particle change used to return the trimmed final state:
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G4ParticleChange fParticleChange;
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G4double fRussianRouletteKillingProbability = -1.0;
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};
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#endif
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