Gabriele Cosmo
158 lines
5.2 KiB
C++
158 lines
5.2 KiB
C++
//
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// ********************************************************************
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// * DISCLAIMER *
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// * *
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// * The following disclaimer summarizes all the specific disclaimers *
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// * of contributors to this software. The specific disclaimers,which *
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// * govern, are listed with their locations in: *
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// * http://cern.ch/geant4/license *
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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. *
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// * *
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// * This code implementation is the intellectual property of the *
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// * GEANT4 collaboration. *
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// * By copying, distributing or modifying the Program (or any work *
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// * based on the Program) you indicate your acceptance of this *
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// * statement, and all its terms. *
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// ********************************************************************
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//
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// $Id: G4BetheHeitlerModel.hh,v 1.3 2005/05/12 11:06:42 vnivanch Exp $
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// GEANT4 tag $Name: geant4-08-00 $
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//
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// -------------------------------------------------------------------
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//
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// GEANT4 Class header file
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//
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//
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// File name: G4BetheHeitlerModel
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//
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// Author: Vladimir Ivanchenko on base of Michel Maire code
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//
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// Creation date: 19.04.2005
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//
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// Modifications:
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//
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// Class Description:
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//
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// Implementation of gamma convertion to e+e- in the field of a nucleus
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//
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// -------------------------------------------------------------------
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//
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#ifndef G4BetheHeitlerModel_h
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#define G4BetheHeitlerModel_h 1
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#include "G4VEmModel.hh"
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#include "G4PhysicsTable.hh"
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class G4ParticleChangeForGamma;
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class G4BetheHeitlerModel : public G4VEmModel
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{
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public:
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G4BetheHeitlerModel(const G4ParticleDefinition* p = 0,
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const G4String& nam = "Bethe-Heitler");
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virtual ~G4BetheHeitlerModel();
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virtual void Initialise(const G4ParticleDefinition*, const G4DataVector&);
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virtual G4double ComputeCrossSectionPerAtom(
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const G4ParticleDefinition*,
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G4double kinEnergy,
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G4double Z,
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G4double A,
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G4double cut,
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G4double emax);
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virtual std::vector<G4DynamicParticle*>* SampleSecondaries(
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const G4MaterialCutsCouple*,
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const G4DynamicParticle*,
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G4double tmin,
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G4double maxEnergy);
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private:
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G4double InitializeCrossSectionPerAtom(G4double energy, G4double Z);
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G4double ScreenFunction1(G4double ScreenVariable);
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G4double ScreenFunction2(G4double ScreenVariable);
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// hide assignment operator
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G4BetheHeitlerModel & operator=(const G4BetheHeitlerModel &right);
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G4BetheHeitlerModel(const G4BetheHeitlerModel&);
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G4ParticleDefinition* theGamma;
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G4ParticleDefinition* theElectron;
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G4ParticleDefinition* thePositron;
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G4ParticleChangeForGamma* fParticleChange;
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G4PhysicsTable* theCrossSectionTable;
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G4double lowGammaEnergy;
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G4double highGammaEnergy;
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G4int nbins;
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size_t indexZ[120];
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};
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//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
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inline G4double G4BetheHeitlerModel::ComputeCrossSectionPerAtom(
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const G4ParticleDefinition*,
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G4double energy,
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G4double Z, G4double,
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G4double, G4double)
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{
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G4bool b;
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size_t iz = indexZ[G4int(Z)];
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G4double x = (((*theCrossSectionTable)[iz]))->GetValue(energy, b);
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return x;
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}
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//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
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inline G4double G4BetheHeitlerModel::ScreenFunction1(G4double ScreenVariable)
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// compute the value of the screening function 3*PHI1 - PHI2
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{
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G4double screenVal;
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if (ScreenVariable > 1.)
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screenVal = 42.24 - 8.368*std::log(ScreenVariable+0.952);
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else
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screenVal = 42.392 - ScreenVariable*(7.796 - 1.961*ScreenVariable);
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return screenVal;
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}
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//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
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inline G4double G4BetheHeitlerModel::ScreenFunction2(G4double ScreenVariable)
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// compute the value of the screening function 1.5*PHI1 - 0.5*PHI2
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{
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G4double screenVal;
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if (ScreenVariable > 1.)
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screenVal = 42.24 - 8.368*std::log(ScreenVariable+0.952);
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else
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screenVal = 41.405 - ScreenVariable*(5.828 - 0.8945*ScreenVariable);
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return screenVal;
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}
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//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
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#endif
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