include/Geant4/G4BaierKatkov.hh

0001 //
0002 // ********************************************************************
0003 // * License and Disclaimer                                           *
0004 // *                                                                  *
0005 // * The  Geant4 software  is  copyright of the Copyright Holders  of *
0006 // * the Geant4 Collaboration.  It is provided  under  the terms  and *
0007 // * conditions of the Geant4 Software License,  included in the file *
0008 // * LICENSE and available at  http://cern.ch/geant4/license .  These *
0009 // * include a list of copyright holders.                             *
0010 // *                                                                  *
0011 // * Neither the authors of this software system, nor their employing *
0012 // * institutes,nor the agencies providing financial support for this *
0013 // * work  make  any representation or  warranty, express or implied, *
0014 // * regarding  this  software system or assume any liability for its *
0015 // * use.  Please see the license in the file  LICENSE  and URL above *
0016 // * for the full disclaimer and the limitation of liability.         *
0017 // *                                                                  *
0018 // * This  code  implementation is the result of  the  scientific and *
0019 // * technical work of the GEANT4 collaboration.                      *
0020 // * By using,  copying,  modifying or  distributing the software (or *
0021 // * any work based  on the software)  you  agree  to acknowledge its *
0022 // * use  in  resulting  scientific  publications,  and indicate your *
0023 // * acceptance of all terms of the Geant4 Software license.          *
0024 // ********************************************************************
0025 //
0026 // Author:      Alexei Sytov
0027 // Co-author:   Gianfranco Paterno (modifications & testing)
0028 // On the base of the CRYSTALRAD realization of the Baier-Katkov integral:
0029 // A. I. Sytov, V. V. Tikhomirov, and L. Bandiera PRAB 22, 064601 (2019)
0030
0031 #ifndef G4BaierKatkov_h
0032 #define G4BaierKatkov_h 1
0033
0034 #include "globals.hh"
0035 #include <CLHEP/Units/SystemOfUnits.h>
0036 #include <vector>
0037 #include "G4ThreeVector.hh"
0038
0039 #include "G4VFastSimulationModel.hh"
0040
0041 /** \file G4BaierKatkov.hh
0042 * \brief Definition of the G4BaierKatkov class
0043 * This class is designed for the calculation of radiation probability, radiation point
0044 * and the parameters of the photon produced as well as spectrum accumulation using
0045 * the Baier-Katkov integral:
0046 * V. N. Baier, V. M. Katkov, and V. M. Strakhovenko,
0047 * Electromagnetic Processes at High Energies in Oriented Single Crystals
0048 * (World Scientific, Singapore, 1998).
0049 */
0050
0051 class G4BaierKatkov
0052 {
0053 public:
0054     // default constructor
0055     G4BaierKatkov();
0056
0057     // destructor
0058     ~G4BaierKatkov() = default;
0059
0060     /**
0061        You may call DoRadiation at each step of your trajectory
0062        CAUTION: please ensure that your steps are physically small enough for calculation
0063        of the radiation type you are interested in
0064        CAUTION: do ResetRadIntegral() before the start of a new trajectory
0065
0066        1) change some model defaults if necessary
0067          (SetSinglePhotonRadiationProbabilityLimit,
0068           SetNSmallTrajectorySteps, SetSpectrumEnergyRange)
0069        2) call DoRadiation at each step of your trajectory
0070        3) if DoRadiation returns TRUE, this means that a photon is produced (not added
0071           as a secondary yet) and its parameters are calculated.
0072        4) You may generate a new photon using GeneratePhoton either with
0073           the parameters calculated in DoRadiation or your own parameters.
0074           CAUTION: By now GeneratePhoton works only for a FastSim model
0075        5) Use GetPhotonEnergyInSpectrum() and GetTotalSpectrum() to return calculated
0076           total spectrum (all the photons altogether)
0077           Caution: is not normalized on the event number
0078        6) Get the charged particle parameters in the radiation point:
0079           GetParticleNewTotalEnergy(),
0080           GetParticleNewAngleX(), GetParticleNewAngleY(),
0081           GetNewGlobalTime(),
0082           GetParticleNewCoordinateXYZ()
0083      */
0084
0085     ///get functions
0086
0087     /// get maximal radiation probability to preserve single photon radiation
0088     G4double GetSinglePhotonRadiationProbabilityLimit()
0089     {return fSinglePhotonRadiationProbabilityLimit;}
0090
0091     ///CAUTION! : use the get functions below ONLY AFTER the call of DoRadiation
0092     /// and ONLY IF IT RETURNS true
0093
0094     ///total probability of radiation: needs calculation of DoRadiation first
0095     G4double GetTotalRadiationProbability(){return fTotalRadiationProbability;}
0096     ///get new parameters of the particle
0097     ///(the parameters at the point of radiation emission)
0098     ///needs calculation of DoRadiation first
0099     G4double GetParticleNewTotalEnergy(){return fNewParticleEnergy;}
0100     G4double GetParticleNewAngleX(){return fNewParticleAngleX;}
0101     G4double GetParticleNewAngleY(){return fNewParticleAngleY;}
0102     G4double GetNewGlobalTime(){return fNewGlobalTime;}
0103     const G4ThreeVector& GetParticleNewCoordinateXYZ(){return fNewParticleCoordinateXYZ;}
0104
0105   ///get photon energies (x-value in spectrum)
0106   const std::vector<G4double>& GetPhotonEnergyInSpectrum()
0107   {return fPhotonEnergyInSpectrum;}
0108
0109   ///get fTotalSpectrum after finishing the trajectory part with DoRadiation
0110   const std::vector<G4double>& GetTotalSpectrum(){return fTotalSpectrum;}
0111
0112     ///set functions
0113
0114     ///set maximal radiation probability to preserve single photon radiation
0115     void SetSinglePhotonRadiationProbabilityLimit(G4double wmax)
0116     {fSinglePhotonRadiationProbabilityLimit = wmax;}
0117
0118     ///number of steps in a trajectory small piece before
0119     ///the next call of the radiation integral
0120     void SetNSmallTrajectorySteps(G4int nSmallTrajectorySteps)
0121     {fNSmallTrajectorySteps = nSmallTrajectorySteps;}
0122
0123     ///reinitialize intermediate integrals fFa, fSs, fSc, fSsx, fSsy, fScx, fScy;
0124     ///reset radiation integral internal variables to defaults;
0125     ///reset the trajectory and radiation probability along the trajectory
0126     void ResetRadIntegral();
0127
0128     ///setting the number of photons in sampling of Baier-Katkov Integral
0129     ///(MC integration by photon energy and angles <=> photon momentum)
0130     void SetSamplingPhotonsNumber(G4int nPhotons){fNMCPhotons = nPhotons;}
0131
0132     ///setting the number of radiation angles 1/gamma, defining the width of
0133     ///the angular distribution of photon sampling in the Baier-Katkov Integral
0134     void SetRadiationAngleFactor(G4double radiationAngleFactor)
0135     {fRadiationAngleFactor = radiationAngleFactor;}
0136
0137     ///CAUTION, the bins width is logarithmic
0138     ///Do not worry if the maximal energy > particle energy.
0139     ///This elements of spectrum with non-physical energies
0140     ///will not be processed (they will be 0).
0141     void SetSpectrumEnergyRange(G4double emin,
0142                                 G4double emax,
0143                                 G4int numberOfBins);
0144     /// SetSpectrumEnergyRange also calls ResetRadIntegral()
0145
0146     void SetMinPhotonEnergy(G4double emin){SetSpectrumEnergyRange(emin,
0147                                                                   fMaxPhotonEnergy,
0148                                                                   fNBinsSpectrum);}
0149     void SetMaxPhotonEnergy(G4double emax){SetSpectrumEnergyRange(fMinPhotonEnergy,
0150                                                                   emax,
0151                                                                   fNBinsSpectrum);}
0152     void SetNBinsSpectrum(G4int nbin){SetSpectrumEnergyRange(fMinPhotonEnergy,
0153                                                              fMaxPhotonEnergy,
0154                                                              nbin);}
0155
0156     /// Increase the statistic of virtual photons in a certain energy region
0157     /// CAUTION! : don't do it before SetSpectrumEnergyRange or SetMinPhotonEnergy
0158     void AddStatisticsInPhotonEnergyRegion(G4double emin, G4double emax,
0159                                            G4int timesPhotonStatistics);
0160
0161     /// Virtual collimator masks the selection of photon angles in fTotalSpectrum
0162     /// Virtual collimator doesn't influence on Geant4 simulations.
0163     void SetVirtualCollimator(G4double virtualCollimatorAngularDiameter)
0164          {fVirtualCollimatorAngularDiameter=virtualCollimatorAngularDiameter;}
0165
0166     /// add the new elements of the trajectory, calculate radiation in a crystal
0167     /// see complete description in G4BaierKatkov::DoRadiation
0168     /// calls RadIntegral and all the necessary functions
0169     /// sets the parameters of a photon produced (if any)
0170     /// using SetPhotonProductionParameters()
0171     /// returns true in the case of photon generation, false if not
0172     G4bool DoRadiation(G4double etotal, G4double mass,
0173                        G4double angleX, G4double angleY,
0174                        G4double angleScatteringX, G4double angleScatteringY,
0175                        G4double step, G4double globalTime,
0176                        G4ThreeVector coordinateXYZ,
0177                        G4bool flagEndTrajectory=false);
0178
0179     /// generates secondary photon belonging to fastStep with variables
0180     /// photon energy, momentum direction, coordinates and global time
0181     /// CALCULATED IN DoRadiation => USE IT ONLY AFTER DoRadiation returns true
0182     void GeneratePhoton(G4FastStep &fastStep);
0183
0184 private:
0185
0186     ///set functions
0187
0188     ///function setting the photon sampling parameters in the Baier-Katkov integral;
0189     ///only the maximal energy is set, while fMinPhotonEnergy is used as a minimal energy;
0190     ///the angles set the angular distribution (the tails are infinite)
0191     void SetPhotonSamplingParameters(G4double ekin,
0192                                    G4double minPhotonAngleX, G4double maxPhotonAngleX,
0193                                    G4double minPhotonAngleY, G4double maxPhotonAngleY);
0194
0195     ///main functions:
0196
0197     ///generation of the photons in sampling of Baier-Katkov Integral
0198     ///(MC integration by photon energy and angles <=> by photon momentum)
0199     void GeneratePhotonSampling();
0200
0201     ///Baier-Katkov method: calculation of integral, spectrum, full probability;
0202     ///returns the total radiation probability;
0203     ///calculates the radiation spectrum on this trajectory piece
0204     G4double RadIntegral(G4double etotal, G4double mass,
0205                          std::vector<G4double> &vectorParticleAnglesX,
0206                          std::vector<G4double> &vectorParticleAnglesY,
0207                          std::vector<G4double> &vectorScatteringAnglesX,
0208                          std::vector<G4double> &vectorScatteringAnglesY,
0209                          std::vector<G4double> &vectorSteps,
0210                          G4int imin);
0211
0212     ///set photon production parameters (returns false if no photon produced)
0213     ///accumulates fTotalSpectrum
0214     ///CAUTION: it is an accessory function of DoRadiation, do not use it separately
0215     G4bool SetPhotonProductionParameters(G4double etotal, G4double mass);
0216
0217     G4int FindVectorIndex(std::vector<G4double> &myvector, G4double value);
0218
0219     G4double fTotalRadiationProbability = 0.;
0220     G4double fSinglePhotonRadiationProbabilityLimit=0.25;//Maximal radiation
0221                                          //probability to preserve single photon radiation
0222
0223     //number of steps in a trajectory piece before the next call of the radiation integral
0224     G4int fNSmallTrajectorySteps=10000;
0225     ///trajectory element No (the first element of the array feeded in RadIntegral)
0226     G4int fImin0 = 0;
0227     ///Monte Carlo statistics of photon sampling in Baier-Katkov with 1 trajectory
0228     G4int fNMCPhotons =150;
0229     ///the number of bins in photon spectrum
0230     G4int fNBinsSpectrum = 110;
0231     G4double fMinPhotonEnergy = 0.1*CLHEP::MeV;//min energy in spectrum output
0232     G4double fMaxPhotonEnergy = 1*CLHEP::GeV;  //max energy in spectrum output
0233     G4double fLogEmaxdEmin = 1.;// = log(fMaxPhotonEnergy/fMinPhotonEnergy),
0234                                // 1/normalizing coefficient in
0235                                // 1/E distribution between
0236                                // fMinPhotonEnergy and fMaxPhotonEnergy
0237                                // is used only for spectrum output, not for simulations
0238                                //(we take bremsstrahlung for photon sampling)
0239     G4double fLogEdEmin = 1.;   // = log(E/fMinPhotonEnergy), the same as fLogEmaxdEmin
0240                                // but with the particle energy as the maximal limit
0241
0242     G4double fVirtualCollimatorAngularDiameter=1.;//default, infinite angle
0243     std::vector<G4bool> fInsideVirtualCollimator;
0244
0245     ///data of the phootn energy range with additional statistics
0246     std::vector<G4double> fLogAddRangeEmindEmin;//=G4Log(emin/fMinPhotonEnergy)
0247     std::vector<G4double> fLogAddRangeEmaxdEmin;//=G4Log(emax/fMinPhotonEnergy)
0248     std::vector<G4int> fTimesPhotonStatistics;
0249
0250     ///number of trajectories
0251     //(at each of the Baier-Katkov Integral is calculated for the same photons)
0252     G4int fItrajectories = 0;
0253
0254     G4double fEph0=0;   //energy of the photon produced
0255     G4ThreeVector PhMomentumDirection;   //momentum direction of the photon produced
0256
0257     ///Radiation integral variables
0258     G4double fMeanPhotonAngleX =0.;        //average angle of radiated photon direction
0259                                            //in sampling, x-plane
0260     G4double fParamPhotonAngleX=1.e-3*CLHEP::rad; //a parameter radiated photon
0261                                            //sampling distribution, x-plane
0262     G4double fMeanPhotonAngleY =0.;        //average angle of radiated photon direction
0263                                            //in sampling, y-plane
0264     G4double fParamPhotonAngleY=1.e-3*CLHEP::rad; //a parameter radiated photon
0265                                            //sampling distribution, y-plane
0266     G4double fRadiationAngleFactor = 4.; // number of radiation angles 1/gamma:
0267                                          // more fRadiationAngleFactor =>
0268                                          // higher fParamPhotonAngleX and Y
0269
0270     ///new particle parameters (the parameters at the point of radiation emission)
0271     G4double fNewParticleEnergy=0;
0272     G4double fNewParticleAngleX=0;
0273     G4double fNewParticleAngleY=0;
0274     G4double fNewGlobalTime=0;
0275     G4ThreeVector fNewParticleCoordinateXYZ;
0276
0277     ///sampling of the energy and the angles of a photon emission
0278     ///(integration variables, Monte Carlo integration)
0279     std::vector<G4double> fPhotonEnergyInIntegral;
0280     std::vector<G4double> fPhotonAngleInIntegralX;
0281     std::vector<G4double> fPhotonAngleInIntegralY;
0282     std::vector<G4double> fPhotonAngleNormCoef;
0283     ///spectrum bin index for each photon
0284     std::vector<G4double> fIBinsSpectrum;
0285     ///the vector of the discrete CDF of the radiation of sampling photons
0286     std::vector<G4double> fPhotonProductionCDF;
0287
0288     ///vectors of the trajectory
0289     std::vector<G4double> fParticleAnglesX;
0290     std::vector<G4double> fParticleAnglesY;
0291     std::vector<G4double> fScatteringAnglesX;
0292     std::vector<G4double> fScatteringAnglesY;
0293     std::vector<G4double> fSteps;
0294     std::vector<G4double> fGlobalTimes;
0295     std::vector<G4ThreeVector> fParticleCoordinatesXYZ;
0296
0297     ///intermediate integrals (different for each photon energy value)!!!
0298     std::vector<G4double> fFa;//phase
0299     std::vector<G4double> fSs;
0300     std::vector<G4double> fSc;
0301     std::vector<G4double> fSsx;
0302     std::vector<G4double> fSsy;
0303     std::vector<G4double> fScx;
0304     std::vector<G4double> fScy;
0305
0306     ///output
0307     std::vector<G4double> fPhotonEnergyInSpectrum; //energy values in spectrum
0308
0309     std::vector<G4int> fNPhotonsPerBin; //number of photons per spectrum bin
0310                                    //(accumulating during total run)
0311
0312     std::vector<G4double> fSpectrum; //spectrum normalized by the total
0313                         //radiation probability of one particle at one call of RadIntegral
0314
0315     std::vector<std::vector<G4double>> fAccumSpectrum; //accumulate Spectrum during
0316                                              //the part of a trajectory
0317
0318     std::vector<G4double> fAccumTotalSpectrum; //spectrum normalized by the total
0319                                           //radiation probability summed
0320                                           //for all the particles (is not divided
0321                                           //of one particle number fNPhotonsPerBin)
0322
0323     std::vector<G4double> fTotalSpectrum; //spectrum normalized by
0324                                      //the total radiation probability summed
0325                                      //for all the particles
0326                                      //(is divided by the photon number fNPhotonsPerBin)
0327                                      //multiplied by the number of trajectories
0328                                      //(fItrajectories)
0329
0330     std::vector<G4double> fImax0; //trajectory element numbers at the end of each
0331                             //small piece; G4double just for security of some operations
0332     ///total radiation probability along this trajectory
0333     std::vector<G4double> fTotalRadiationProbabilityAlongTrajectory;
0334 };
0335
0336 #endif