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//
// -------------------------------------------------------------------
//
// GEANT4 Class header file
//
//
// File name:     G4SeltzerBergerModel
//
// Author:        Andreas Schaelicke & Vladimir Ivantchenko
//
// Creation date: 04.10.2011
//
// Modifications:
//
// 24.07.2018 Introduced possibility to use sampling tables to sample the
//            emitted photon energy (instead of using rejectio) from the 
//            Seltzer-Berger scalled DCS for bremsstrahlung photon emission. 
//            Using these sampling tables option gives faster(30-70%) final 
//            state generation than the original rejection but takes some 
//            extra memory (+ ~6MB in the case of the full CMS detector). 
//            (M Novak)
//
// Class Description:
//
// Implementation of the bremssrahlung energy spectrum using
// 1. S.M. Seltzer and M.J. Berger Nucl. Instr. Meth. B12 (1985) 95
// 2. S.M. Seltzer and M.J. Berger Atomic data and Nuclear Data
//    Tables 35 (1986) 345

// -------------------------------------------------------------------
//

#ifndef G4SeltzerBergerModel_h
#define G4SeltzerBergerModel_h 1

#include "G4VEmModel.hh"
#include "G4eBremsstrahlungRelModel.hh"
#include "globals.hh"

class G4Physics2DVector;
class G4SBBremTable;
class G4ParticleChangeForLoss;

class G4SeltzerBergerModel : public G4VEmModel
{

public:

  explicit G4SeltzerBergerModel(const G4ParticleDefinition* p = nullptr,
                                const G4String& nam = "eBremSB");

  ~G4SeltzerBergerModel() override;

  void Initialise(const G4ParticleDefinition*, const G4DataVector&) override;

  void InitialiseLocal(const G4ParticleDefinition*,
                       G4VEmModel* masterModel) override;

  G4double ComputeDEDXPerVolume(const G4Material*,
                                const G4ParticleDefinition*,
                                G4double ekin,
                                G4double cutEnergy) override;

  G4double ComputeCrossSectionPerAtom(const G4ParticleDefinition*,
                                      G4double ekin,
                                      G4double zet,
                                      G4double,
                                      G4double cutEnergy,
                                      G4double maxEnergy = DBL_MAX) override;

  void SampleSecondaries(std::vector<G4DynamicParticle*>*,
                         const G4MaterialCutsCouple*,
                         const G4DynamicParticle*,
			 G4double cutEnergy,
                         G4double maxEnergy) override;

  void SetupForMaterial(const G4ParticleDefinition*,
                        const G4Material*, G4double) override;

  G4double MinPrimaryEnergy(const G4Material*,
                            const G4ParticleDefinition*,
                            G4double cutEnergy) override;

  inline void SetBicubicInterpolationFlag(G4bool val) 
  { fIsUseBicubicInterpolation = val; };

  // hide assignment operator and cctr
  G4SeltzerBergerModel & operator=(const G4SeltzerBergerModel &right) = delete;
  G4SeltzerBergerModel(const G4SeltzerBergerModel&) = delete;

private:

  void SetParticle(const G4ParticleDefinition* p);

  void ReadData(G4int Z);

  G4double ComputeBremLoss(G4double cutEnergy);

  G4double ComputeXSectionPerAtom(G4double cutEnergy);

  G4double ComputeDXSectionPerAtom(G4double gammaEnergy);

  G4double SampleEnergyTransfer(const G4double kineticEnergy, 
                                const G4double logKineticEnergy, 
                                const G4double cut,
                                const G4double emax);

protected:

  G4ParticleChangeForLoss* fParticleChange{nullptr};

private:

  static constexpr G4int gMaxZet{101};
  static constexpr G4double gExpNumLimit{-12.};
  static G4double gYLimitData[gMaxZet];
  static G4Physics2DVector* gSBDCSData[gMaxZet];
  static G4SBBremTable* gSBSamplingTable;
  static const G4double gBremFactor;
  static const G4double gMigdalConstant;

  G4bool fIsUseBicubicInterpolation{false};
  G4bool fIsUseSamplingTables{true};
  G4bool fIsElectron{true};
  G4bool fIsScatOffElectron{false};
  G4bool isInitializer{false};
  //
  G4int fCurrentIZ{0};
  G4int fNumWarnings{0};

  const G4ParticleDefinition* fPrimaryParticle{nullptr};
  G4ParticleDefinition* fGammaParticle;

  // cash
  G4double fPrimaryKinEnergy{0.};
  G4double fPrimaryTotalEnergy{0.};
  G4double fDensityFactor{0.};
  G4double fDensityCorr{0.};
  G4double fLowestKinEnergy;

  std::size_t fIndx{0};
  std::size_t fIndy{0};
};

#endif