OpFastScintillation.hh

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// Class adapted for LArSoft by Ben Jones, MIT 10/10/12
//
// This class is a physics process based on the standard Geant4
// scintillation process.
//
// It has been stripped down and adapted to form the backbone of
// the LArG4 fast optical simulation.  Photons, instead of being
// produced and added to the geant4 particle stack, are logged
// and used to predict the visibility of this step to each PMT in
// the detector.
//
// The photonvisibilityservice looks up the visibility of the relevant
// xyz point, and if a photon is detected at a given PMT, one OnePhoton
// object is logged in the OpDetPhotonTable
//
// At the end of the event, the OpDetPhotonTable is read out
// by LArG4, and detected photons are stored in the event.
//
// This process can be used alongside the standard Cerenkov process,
// which does step geant4 opticalphotons.  Both the fast scintillation
// table and the geant4 sensitive detectors are read out by LArG4 to
// produce a combined SimPhoton collection.
//
//
//
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// * technical work of the GEANT4 collaboration.                      *
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//
//
// GEANT4 tag $Name: not supported by cvs2svn $
//
// 
// Scintillation Light Class Definition 
//
// File:        OpFastScintillation.hh  
// Description: Discrete Process - Generation of Scintillation Photons
// Version:     1.0
// Created:     1998-11-07
// Author:      Peter Gumplinger
// Updated:     2010-10-20 Allow the scintillation yield to be a function
//                         of energy deposited by particle type
//                         Thanks to Zach Hartwig (Department of Nuclear
//                         Science and Engineeering - MIT)
//              2005-07-28 add G4ProcessType to constructor
//              2002-11-21 change to user G4Poisson for small MeanNumPotons
//              2002-11-07 allow for fast and slow scintillation
//              2002-11-05 make use of constant material properties
//              2002-05-16 changed to inherit from VRestDiscreteProcess
//              2002-05-09 changed IsApplicable method
//              1999-10-29 add method and class descriptors
//
// mail:        gum@triumf.ca
//

#ifndef OpFastScintillation_h
#define OpFastScintillation_h 1

// Includes

#include "Geant4/globals.hh"
#include "Geant4/templates.hh"
#include "Geant4/G4ThreeVector.hh"
#include "Geant4/G4ParticleMomentum.hh"
#include "Geant4/G4Step.hh"
#include "Geant4/G4VRestDiscreteProcess.hh"
#include "Geant4/G4OpticalPhoton.hh"
#include "Geant4/G4DynamicParticle.hh"
#include "Geant4/G4Material.hh" 
#include "Geant4/G4PhysicsTable.hh"
#include "Geant4/G4MaterialPropertiesTable.hh"
#include "Geant4/G4PhysicsOrderedFreeVector.hh"
#include "Geant4/G4EmSaturation.hh"

#include "fhiclcpp/ParameterSet.h"
#include "TF1.h"

// Class Description:
// RestDiscrete Process - Generation of Scintillation Photons.
// Class inherits publicly from G4VRestDiscreteProcess.
// Class Description - End:

// Class Definition

namespace larg4{

class OpFastScintillation : public G4VRestDiscreteProcess
{

private:

        // Operators
  
        // OpFastScintillation& operator=(const OpFastScintillation &right);
  
public: // Without description
  
        // Constructors and Destructor

        OpFastScintillation(const G4String& processName = "Scintillation", G4ProcessType type = fElectromagnetic);  
        OpFastScintillation(const OpFastScintillation &right);

        ~OpFastScintillation(); 

        // Methods

public: // With description

        // OpFastScintillation Process has both PostStepDoIt (for energy 
        // deposition of particles in flight) and AtRestDoIt (for energy
        // given to the medium by particles at rest)

        virtual G4bool IsApplicable(const G4ParticleDefinition& aParticleType);
        // Returns true -> 'is applicable', for any particle type except
        // for an 'opticalphoton' and for short-lived particles

        G4double GetMeanFreePath(const G4Track& aTrack,
                                       G4double ,
                                       G4ForceCondition* );
        // Returns infinity; i. e. the process does not limit the step,
        // but sets the 'StronglyForced' condition for the DoIt to be 
        // invoked at every step.

 
        G4double GetMeanLifeTime(const G4Track& aTrack,
                                 G4ForceCondition* );
        // Returns infinity; i. e. the process does not limit the time,
        // but sets the 'StronglyForced' condition for the DoIt to be
        // invoked at every step.

        virtual G4VParticleChange* PostStepDoIt(const G4Track& aTrack, 
                                        const G4Step&  aStep);
        virtual G4VParticleChange* AtRestDoIt (const G4Track& aTrack,
                                       const G4Step& aStep);

        // These are the methods implementing the scintillation process.

        void SetTrackSecondariesFirst(const G4bool state);
        // If set, the primary particle tracking is interrupted and any
        // produced scintillation photons are tracked next. When all 
        // have been tracked, the tracking of the primary resumes.

        void SetFiniteRiseTime(const G4bool state);
        // If set, the OpFastScintillation process expects the user to have
        // set the constant material property FAST/SLOWSCINTILLATIONRISETIME.

        G4bool GetTrackSecondariesFirst() const;
        // Returns the boolean flag for tracking secondaries first.

        G4bool GetFiniteRiseTime() const;
        // Returns the boolean flag for a finite scintillation rise time.
        
        void SetScintillationYieldFactor(const G4double yieldfactor);
        // Called to set the scintillation photon yield factor, needed when
        // the yield is different for different types of particles. This
        // scales the yield obtained from the G4MaterialPropertiesTable.

        G4double GetScintillationYieldFactor() const;
        // Returns the photon yield factor.

        void SetScintillationExcitationRatio(const G4double excitationratio);
        // Called to set the scintillation exciation ratio, needed when
        // the scintillation level excitation is different for different
        // types of particles. This overwrites the YieldRatio obtained
        // from the G4MaterialPropertiesTable.

        G4double GetScintillationExcitationRatio() const;
        // Returns the scintillation level excitation ratio.

        G4PhysicsTable* GetFastIntegralTable() const;
        // Returns the address of the fast scintillation integral table.

        G4PhysicsTable* GetSlowIntegralTable() const;
        // Returns the address of the slow scintillation integral table.

        void AddSaturation(G4EmSaturation* sat) { emSaturation = sat; }
        // Adds Birks Saturation to the process.

        void RemoveSaturation() { emSaturation = NULL; }
        // Removes the Birks Saturation from the process.

        G4EmSaturation* GetSaturation() const { return emSaturation; }
        // Returns the Birks Saturation.

        void SetScintillationByParticleType(const G4bool );
        // Called by the user to set the scintillation yield as a function
        // of energy deposited by particle type

        G4bool GetScintillationByParticleType() const
        { return scintillationByParticleType; }
        // Return the boolean that determines the method of scintillation
        // production

        void DumpPhysicsTable() const;
        // Prints the fast and slow scintillation integral tables.

        std::vector<double> GetVUVTime(double, int);
        std::vector<double> GetVisibleTimeOnlyCathode(double, int);
       // Update configuration parameters.

       //void reconfigure(const fhicl::ParameterSet& pset);

protected:

        void BuildThePhysicsTable();
        // It builds either the fast or slow scintillation integral table; 
        // or both. 

  
        bool RecordPhotonsProduced(const G4Step& aStep, double N);
        // Note the production of N photons in at point xyz.
        //  pass on to generate detector response, etc.


        // Class Data Members

        G4PhysicsTable* theSlowIntegralTable;
        G4PhysicsTable* theFastIntegralTable;

        G4bool fTrackSecondariesFirst;
        G4bool fFiniteRiseTime;

        G4double YieldFactor;

        G4double ExcitationRatio;

        G4bool scintillationByParticleType;

private:

        G4double single_exp(G4double t, G4double tau2);
        G4double bi_exp(G4double t, G4double tau1, G4double tau2);

        // emission time distribution when there is a finite rise time
        G4double sample_time(G4double tau1, G4double tau2);

        G4EmSaturation* emSaturation;
        // functions and parameters for the propagation time parametrization
        TF1 const* functions_vuv[8];
        TF1 const* functions_vis[5];                     
        double fd_break;
        double fd_max;
        double ftf1_sampling_factor;
        double ft0_max, ft0_break_point; 
        //double fGlobalTimeOffset;  

        void ProcessStep( const G4Step& step);

};

  double finter_d(double*, double*);
  double LandauPlusExpoFinal(double*, double*);

// Inline methods

inline 
G4bool OpFastScintillation::IsApplicable(const G4ParticleDefinition& aParticleType)
{
       if (aParticleType.GetParticleName() == "opticalphoton") return false;
       if (aParticleType.IsShortLived()) return false;

       return true;
}

inline 
void OpFastScintillation::SetTrackSecondariesFirst(const G4bool state) 
{
        fTrackSecondariesFirst = state;
}

inline
void OpFastScintillation::SetFiniteRiseTime(const G4bool state)
{
        fFiniteRiseTime = state;
}

inline
G4bool OpFastScintillation::GetTrackSecondariesFirst() const
{
        return fTrackSecondariesFirst;
}

inline 
G4bool OpFastScintillation::GetFiniteRiseTime() const
{
        return fFiniteRiseTime;
}

inline
void OpFastScintillation::SetScintillationYieldFactor(const G4double yieldfactor)
{
        YieldFactor = yieldfactor;
}

inline
G4double OpFastScintillation::GetScintillationYieldFactor() const
{
        return YieldFactor;
}

inline
void OpFastScintillation::SetScintillationExcitationRatio(const G4double excitationratio)
{
        ExcitationRatio = excitationratio;
}

inline
G4double OpFastScintillation::GetScintillationExcitationRatio() const
{
        return ExcitationRatio;
}

inline
G4PhysicsTable* OpFastScintillation::GetSlowIntegralTable() const
{
        return theSlowIntegralTable;
}

inline
G4PhysicsTable* OpFastScintillation::GetFastIntegralTable() const
{
        return theFastIntegralTable;
}

inline
void OpFastScintillation::DumpPhysicsTable() const
{
        if (theFastIntegralTable) {
           G4int PhysicsTableSize = theFastIntegralTable->entries();
           G4PhysicsOrderedFreeVector *v;

           for (G4int i = 0 ; i < PhysicsTableSize ; i++ )
           {
                v = (G4PhysicsOrderedFreeVector*)(*theFastIntegralTable)[i];
                v->DumpValues();
           }
         }

        if (theSlowIntegralTable) {
           G4int PhysicsTableSize = theSlowIntegralTable->entries();
           G4PhysicsOrderedFreeVector *v;

           for (G4int i = 0 ; i < PhysicsTableSize ; i++ )
           {
                v = (G4PhysicsOrderedFreeVector*)(*theSlowIntegralTable)[i];
                v->DumpValues();
           }
         }
}

inline
G4double OpFastScintillation::single_exp(G4double t, G4double tau2)
{
         return std::exp(-1.0*t/tau2)/tau2;
}

inline
G4double OpFastScintillation::bi_exp(G4double t, G4double tau1, G4double tau2)
{
         return std::exp(-1.0*t/tau2)*(1-std::exp(-1.0*t/tau1))/tau2/tau2*(tau1+tau2);
}

} //namespace

#endif /* OpFastScintillation_h */