// // ******************************************************************** // * License and Disclaimer * // * * // * The Geant4 software is copyright of the Copyright Holders of * // * the Geant4 Collaboration. It is provided under the terms and * // * conditions of the Geant4 Software License, included in the file * // * LICENSE and available at http://cern.ch/geant4/license . These * // * include a list of copyright holders. * // * * // * Neither the authors of this software system, nor their employing * // * institutes,nor the agencies providing financial support for this * // * work make any representation or warranty, express or implied, * // * regarding this software system or assume any liability for its * // * use. Please see the license in the file LICENSE and URL above * // * for the full disclaimer and the limitation of liability. * // * * // * This code implementation is the result of the scientific and * // * technical work of the GEANT4 collaboration. * // * By using, copying, modifying or distributing the software (or * // * any work based on the software) you agree to acknowledge its * // * use in resulting scientific publications, and indicate your * // * acceptance of all terms of the Geant4 Software license. * // ******************************************************************** // // $Id: G4eCoulombScatteringModel.hh,v 1.49 2009/10/10 15:16:57 vnivanch Exp $ // GEANT4 tag $Name: geant4-09-03-cand-01 $ // // ------------------------------------------------------------------- // // GEANT4 Class header file // // // File name: G4eCoulombScatteringModel // // Author: Vladimir Ivanchenko // // Creation date: 19.02.2006 // // Modifications: // 01.08.06 V.Ivanchenko extend upper limit of table to TeV and review the // logic of building - only elements from G4ElementTable // 08.08.06 V.Ivanchenko build internal table in ekin scale, introduce faclim // 19.08.06 V.Ivanchenko add inline function ScreeningParameter and // make some members protected // 09.10.07 V.Ivanchenko reorganized methods, add cut dependence in scattering off e- // 09.06.08 V.Ivanchenko add SelectIsotope and sampling of the recoil ion // 17.06.09 C.Consoalndi modified SetupTarget method - remove kinFactor // // // Class Description: // // Implementation of eCoulombScattering of pointlike charge particle // on Atomic Nucleus for interval of scattering anles in Lab system // thetaMin - ThetaMax, nucleus recoil is neglected. // The model based on analysis of J.M.Fernandez-Varea et al. // NIM B73(1993)447 originated from G.Wentzel Z.Phys. 40(1927)590 with // screening parameter from H.A.Bethe Phys. Rev. 89 (1953) 1256. // // ------------------------------------------------------------------- // #ifndef G4eCoulombScatteringModel_h #define G4eCoulombScatteringModel_h 1 #include "G4VEmModel.hh" #include "G4PhysicsTable.hh" #include "globals.hh" #include "G4NistManager.hh" #include class G4ParticleChangeForGamma; class G4ParticleDefinition; class G4eCoulombScatteringModel : public G4VEmModel { public: G4eCoulombScatteringModel(const G4String& nam = "eCoulombScattering"); virtual ~G4eCoulombScatteringModel(); virtual void Initialise(const G4ParticleDefinition*, const G4DataVector&); virtual G4double ComputeCrossSectionPerAtom( const G4ParticleDefinition*, G4double kinEnergy, G4double Z, G4double A, G4double cut, G4double emax); virtual void SampleSecondaries(std::vector*, const G4MaterialCutsCouple*, const G4DynamicParticle*, G4double tmin, G4double maxEnergy); inline void SetRecoilThreshold(G4double eth); protected: G4double CrossSectionPerAtom(); G4double SampleCosineTheta(); inline void DefineMaterial(const G4MaterialCutsCouple*); inline void SetupParticle(const G4ParticleDefinition*); inline void SetupKinematic(G4double kinEnergy, G4double cut); inline void SetupTarget(G4double Z, G4double kinEnergy); private: void ComputeMaxElectronScattering(G4double cut); // hide assignment operator G4eCoulombScatteringModel & operator=(const G4eCoulombScatteringModel &right); G4eCoulombScatteringModel(const G4eCoulombScatteringModel&); protected: const G4ParticleDefinition* theProton; const G4ParticleDefinition* theElectron; const G4ParticleDefinition* thePositron; G4ParticleTable* theParticleTable; G4ParticleChangeForGamma* fParticleChange; G4NistManager* fNistManager; const std::vector* pCuts; const G4MaterialCutsCouple* currentCouple; const G4Material* currentMaterial; const G4Element* currentElement; G4int currentMaterialIndex; G4double coeff; G4double cosThetaMin; G4double cosThetaMax; G4double cosTetMinNuc; G4double cosTetMaxNuc; G4double cosTetMaxNuc2; G4double cosTetMaxElec; G4double cosTetMaxElec2; G4double q2Limit; G4double recoilThreshold; G4double elecXSection; G4double nucXSection; G4double ecut; // projectile const G4ParticleDefinition* particle; G4double chargeSquare; G4double spin; G4double mass; G4double tkin; G4double mom2; G4double invbeta2; G4double etag; G4double lowEnergyLimit; // target G4double targetZ; G4double targetMass; G4double screenZ; G4double formfactA; G4int idxelm; G4int iz; private: G4double alpha2; G4double faclim; static G4double ScreenRSquare[100]; static G4double FormFactor[100]; G4bool isInitialised; }; //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... inline void G4eCoulombScatteringModel::DefineMaterial(const G4MaterialCutsCouple* cup) { if(cup != currentCouple) { currentCouple = cup; currentMaterial = cup->GetMaterial(); currentMaterialIndex = currentCouple->GetIndex(); } } //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... inline void G4eCoulombScatteringModel::SetupParticle(const G4ParticleDefinition* p) { // Initialise mass and charge if(p != particle) { particle = p; mass = particle->GetPDGMass(); spin = particle->GetPDGSpin(); G4double q = particle->GetPDGCharge()/eplus; chargeSquare = q*q; tkin = 0.0; } } //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... inline void G4eCoulombScatteringModel::SetupKinematic(G4double ekin, G4double cut) { if(ekin != tkin || ecut != cut) { tkin = ekin; mom2 = tkin*(tkin + 2.0*mass); invbeta2 = 1.0 + mass*mass/mom2; cosTetMinNuc = cosThetaMin; cosTetMaxNuc = cosThetaMax; if(mass < MeV && cosThetaMin < 1.0 && ekin <= 10.*cut) { cosTetMinNuc = ekin*(cosThetaMin + 1.0)/(10.*cut) - 1.0; } ComputeMaxElectronScattering(cut); } } //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... inline void G4eCoulombScatteringModel::SetupTarget(G4double Z, G4double e) { if(Z != targetZ || e != etag) { etag = e; targetZ = Z; iz= G4int(Z); if(iz > 99) iz = 99; targetMass = fNistManager->GetAtomicMassAmu(iz)*amu_c2; screenZ = ScreenRSquare[iz]/mom2; screenZ *=(1.13 + std::min(1.0,3.76*Z*Z*invbeta2*alpha2)); if(mass > MeV) { screenZ *= 2.0; } formfactA = FormFactor[iz]*mom2; cosTetMaxNuc2 = cosTetMaxNuc; if(1 == iz && particle == theProton && cosTetMaxNuc2 < 0.0) { cosTetMaxNuc2 = 0.0; } cosTetMaxElec2 = cosTetMaxElec; } } //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... inline void G4eCoulombScatteringModel::SetRecoilThreshold(G4double eth) { recoilThreshold = eth; } //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... #endif