include/Geant4/G4WentzelOKandVIxSection.hh

0001 //
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0025 //
0026 //
0027 // -------------------------------------------------------------------
0028 //
0029 //
0030 // GEANT4 Class header file
0031 //
0032 //
0033 // File name:     G4WentzelOKandVIxSection
0034 //
0035 // Authors:       V.Ivanchenko and O.Kadri
0036 //
0037 // Creation date: 21.05.2010
0038 //
0039 // Modifications:
0040 //
0041 //
0042 // Class Description:
0043 //
0044 // Implementation of the computation of total and transport cross sections,
0045 // sample scattering angle for the single scattering case.
0046 // to be used by single and multiple scattering models. References:
0047 // 1) G.Wentzel, Z. Phys. 40 (1927) 590.
0048 // 2) J.M. Fernandez-Varea et al., NIM B73 (1993) 447.
0049 //
0050 // -------------------------------------------------------------------
0051 //
0052
0053 #ifndef G4WentzelOKandVIxSection_h
0054 #define G4WentzelOKandVIxSection_h 1
0055
0056 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0057
0058 #include "globals.hh"
0059 #include "G4Material.hh"
0060 #include "G4Element.hh"
0061 #include "G4ElementVector.hh"
0062 #include "G4NistManager.hh"
0063 #include "G4NuclearFormfactorType.hh"
0064 #include "G4ThreeVector.hh"
0065 #include "G4Pow.hh"
0066
0067 class G4ParticleDefinition;
0068 class G4ScreeningMottCrossSection;
0069
0070 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0071
0072 class G4WentzelOKandVIxSection
0073 {
0074
0075 public:
0076
0077   explicit G4WentzelOKandVIxSection(G4bool combined=true);
0078
0079   virtual ~G4WentzelOKandVIxSection();
0080
0081   void Initialise(const G4ParticleDefinition*, G4double CosThetaLim);
0082
0083   void SetupParticle(const G4ParticleDefinition*);
0084
0085   // return cos(ThetaMax) for msc and cos(thetaMin) for single scattering
0086   // cut = DBL_MAX means no scattering off electrons
0087   virtual G4double SetupKinematic(G4double kinEnergy, const G4Material* mat);
0088   G4double SetupTarget(G4int Z, G4double cut);
0089
0090   G4double ComputeTransportCrossSectionPerAtom(G4double CosThetaMax);
0091
0092   G4ThreeVector& SampleSingleScattering(G4double CosThetaMin,
0093                     G4double CosThetaMax,
0094                     G4double elecRatio);
0095
0096   G4double ComputeSecondTransportMoment(G4double CosThetaMax);
0097
0098   inline G4double ComputeNuclearCrossSection(G4double CosThetaMin,
0099                          G4double CosThetaMax);
0100
0101   inline G4double ComputeElectronCrossSection(G4double CosThetaMin,
0102                           G4double CosThetaMax);
0103
0104   inline void SetTargetMass(G4double value);
0105
0106   inline G4double GetMomentumSquare() const;
0107
0108   inline G4double GetCosThetaNuc() const;
0109
0110   inline G4double GetCosThetaElec() const;
0111
0112   //  hide assignment operator
0113   G4WentzelOKandVIxSection & operator=
0114   (const G4WentzelOKandVIxSection &right) = delete;
0115   G4WentzelOKandVIxSection(const  G4WentzelOKandVIxSection&) = delete;
0116
0117 protected:
0118
0119   void ComputeMaxElectronScattering(G4double cut);
0120
0121   void InitialiseA();
0122
0123   inline G4double FlatFormfactor(G4double x);
0124
0125   const G4ParticleDefinition* theProton;
0126   const G4ParticleDefinition* theElectron;
0127   const G4ParticleDefinition* thePositron;
0128   const G4ParticleDefinition* particle = nullptr;
0129   const G4Material* currentMaterial = nullptr;
0130
0131   G4NistManager* fNistManager;
0132   G4Pow*         fG4pow;
0133
0134   G4ScreeningMottCrossSection* fMottXSection = nullptr;
0135
0136   G4ThreeVector temp;
0137
0138   // single scattering parameters
0139   G4double coeff;
0140   G4double cosTetMaxElec = 1.0;
0141   G4double cosTetMaxNuc = 1.0;
0142
0143   // for the combined mode it is cos(thetaMax)
0144   // for single scattering it is cos(thetaMin)
0145   G4double cosThetaMax = 1.0;
0146
0147   G4double chargeSquare = 0.0;
0148   G4double charge3 = 0.0;
0149   G4double spin = 0.0;
0150   G4double mass = 0.0;
0151   G4double tkin = 0.0;
0152   G4double mom2 = 0.0;
0153   G4double momCM2 = 0.0;
0154   G4double invbeta2 = 1.0;
0155   G4double kinFactor = 1.0;
0156   G4double etag = DBL_MAX;
0157   G4double ecut = DBL_MAX;
0158
0159   // target
0160   G4double targetMass;
0161   G4double screenZ = 0.0;
0162   G4double formfactA = 0.0;
0163   G4double factorA2 = 0.0;
0164   G4double factB = 0.0;
0165   G4double factD = 0.0;
0166   G4double fMottFactor = 1.0;
0167   G4double gam0pcmp = 1.0;
0168   G4double pcmp2 = 1.0;
0169
0170   // integer parameters
0171   G4int targetZ = 0;
0172   G4int nwarnings = 0;
0173
0174   G4NuclearFormfactorType fNucFormfactor = fExponentialNF;
0175
0176   G4bool isCombined;
0177
0178   static G4double ScreenRSquareElec[100];
0179   static G4double ScreenRSquare[100];
0180   static G4double FormFactor[100];
0181 };
0182
0183 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0184
0185 inline void G4WentzelOKandVIxSection::SetTargetMass(G4double value)
0186 {
0187   targetMass = value;
0188   factD = std::sqrt(mom2)/value;
0189 }
0190
0191 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0192
0193 inline G4double G4WentzelOKandVIxSection::GetMomentumSquare() const
0194 {
0195   return mom2;
0196 }
0197
0198 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0199
0200 inline G4double G4WentzelOKandVIxSection::GetCosThetaNuc() const
0201 {
0202   return cosTetMaxNuc;
0203 }
0204
0205 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0206
0207 inline G4double G4WentzelOKandVIxSection::GetCosThetaElec() const
0208 {
0209   return cosTetMaxElec;
0210 }
0211
0212 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0213
0214 inline G4double
0215 G4WentzelOKandVIxSection::ComputeNuclearCrossSection(G4double cosTMin,
0216                              G4double cosTMax)
0217 {
0218   return targetZ*kinFactor*fMottFactor*(cosTMin - cosTMax)/
0219     ((1.0 - cosTMin + screenZ)*(1.0 - cosTMax + screenZ));
0220 }
0221
0222 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0223
0224 inline G4double
0225 G4WentzelOKandVIxSection::ComputeElectronCrossSection(G4double cosTMin,
0226                               G4double cosTMax)
0227 {
0228   G4double cost1 = std::max(cosTMin,cosTetMaxElec);
0229   G4double cost2 = std::max(cosTMax,cosTetMaxElec);
0230   return (cost1 <= cost2) ? 0.0 : kinFactor*fMottFactor*(cost1 - cost2)/
0231     ((1.0 - cost1 + screenZ)*(1.0 - cost2 + screenZ));
0232 }
0233
0234 inline G4double G4WentzelOKandVIxSection::FlatFormfactor(G4double x)
0235 {
0236   return 3.0*(std::sin(x) - x*std::cos(x))/(x*x*x);
0237 }
0238
0239 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0240
0241 #endif
0242