Gabriele Cosmo
116 lines
4.9 KiB
C++
116 lines
4.9 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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//
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//
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// --------------------------------------------------------------------
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// GEANT 4 class header file
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//
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// Class Description:
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//
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// An abstract class to model interaction laws, not necessarily.
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// exponential ones.
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// These laws, p(l), are caraterized by their:
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// - non-interaction probability over l:
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// P_NI(l) = 1 - integral(0,l) p(s) ds
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// - effective cross-section at l:
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// sigma_eff(l) = p(l)/P_NI(l) (several forms exist)
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// If several laws compete, the resulting net law has:
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// - an non-interaction probability over a lenght l which
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// is the product of the individual non-interaction probabilities.
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// - an effective cross-section which is the
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// sum on the individual effective cross-sections.
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//
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// ----------------G4VBiasingInteractionLaw ----------------
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//
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// Author: M.Verderi (LLR), November 2013
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// - 05/11/13 : First Implementation
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// --------------------------------------------------------------------
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#ifndef G4VBiasingInteractionLaw_hh
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#define G4VBiasingInteractionLaw_hh 1
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#include "globals.hh"
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#include <vector>
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class G4BiasingProcessInterface;
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class G4VBiasingInteractionLaw {
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public:
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G4VBiasingInteractionLaw(G4String name) : fName(name), fSampledInteractionLength(DBL_MAX) {}
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virtual ~G4VBiasingInteractionLaw() {}
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public:
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const G4String& GetName() const { return fName; }
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// ----------------------------
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// -- Interface to sub-classes:
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// ----------------------------
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protected:
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// -- Sample the distribution for point like interaction (PostStep ones)
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virtual G4double SampleInteractionLength() = 0;
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public:
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// -- Compute non-interaction probability and effective cross-section:
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// -- (probability of interaction over dl = effective_cross-section* dl)
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virtual G4double ComputeNonInteractionProbabilityAt(G4double length) const = 0;
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virtual G4double ComputeEffectiveCrossSectionAt(G4double length) const = 0;
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protected:
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// -- Convenience method, used in many daughters classes :
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// -- update the distribution for a made step of truePathLength size:
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virtual G4double UpdateInteractionLengthForStep(G4double /* truePathLength */) { return DBL_MAX; }
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public:
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// -- Methods to deal with singularities : null cross sections or infinite ones.
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// -- In such cases, weight can not always be computed.
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// -- Tells if this interaction law has singularities:
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virtual G4bool IsSingular() const {return false;}
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// -- method interrogated only in case interaction law is IsSingular() == true:
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virtual G4bool IsEffectiveCrossSectionInfinite() const {return false;}
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// -----------------------------------------
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// -- public interface to protected methods:
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// -----------------------------------------
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public:
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G4double Sample()
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{
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fSampledInteractionLength = SampleInteractionLength();
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return fSampledInteractionLength;
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}
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G4double UpdateForStep(G4double truePathLength)
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{
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fSampledInteractionLength = UpdateInteractionLengthForStep(truePathLength);
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return fSampledInteractionLength;
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}
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G4double GetSampledInteractionLength() const { return fSampledInteractionLength; }
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private:
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G4String fName;
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G4double fSampledInteractionLength;
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};
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#endif
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