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24 | // ******************************************************************** |
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25 | // |
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26 | // $Id: G4eCoulombScatteringModel.hh,v 1.20 2007/10/24 10:42:05 vnivanch Exp $ |
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27 | // GEANT4 tag $Name: geant4-09-01-patch-02 $ |
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28 | // |
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29 | // ------------------------------------------------------------------- |
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30 | // |
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31 | // GEANT4 Class header file |
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32 | // |
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33 | // |
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34 | // File name: G4eCoulombScatteringModel |
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35 | // |
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36 | // Author: Vladimir Ivanchenko |
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37 | // |
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38 | // Creation date: 19.02.2006 |
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39 | // |
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40 | // Modifications: |
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41 | // 01.08.06 V.Ivanchenko extend upper limit of table to TeV and review the |
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42 | // logic of building - only elements from G4ElementTable |
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43 | // 08.08.06 V.Ivanchenko build internal table in ekin scale, introduce faclim |
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44 | // 19.08.06 V.Ivanchenko add inline function ScreeningParameter and |
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45 | // make some members protected |
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46 | // 09.10.07 V.Ivanchenko reorganized methods, add cut dependence in scattering off e- |
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47 | // |
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48 | // Class Description: |
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49 | // |
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50 | // Implementation of eCoulombScattering of pointlike charge particle |
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51 | // on Atomic Nucleus for interval of scattering anles in Lab system |
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52 | // thetaMin - ThetaMax, nucleus recoil is neglected. |
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53 | // The model based on analysis of J.M.Fernandez-Varea et al. |
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54 | // NIM B73(1993)447 originated from G.Wentzel Z.Phys. 40(1927)590 with |
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55 | // screening parameter from H.A.Bethe Phys. Rev. 89 (1953) 1256. |
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56 | // |
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57 | |
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58 | // ------------------------------------------------------------------- |
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59 | // |
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60 | |
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61 | #ifndef G4eCoulombScatteringModel_h |
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62 | #define G4eCoulombScatteringModel_h 1 |
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63 | |
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64 | #include "G4VEmModel.hh" |
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65 | #include "G4PhysicsTable.hh" |
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66 | #include "G4NistManager.hh" |
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67 | #include "globals.hh" |
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68 | |
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69 | class G4ParticleChangeForGamma; |
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70 | class G4ParticleDefinition; |
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71 | |
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72 | class G4eCoulombScatteringModel : public G4VEmModel |
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73 | { |
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74 | |
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75 | public: |
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76 | |
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77 | G4eCoulombScatteringModel(G4double thetaMin = 0.0, G4double thetaMax = pi, |
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78 | G4bool build = false, G4double tlim = TeV*TeV, |
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79 | const G4String& nam = "eCoulombScattering"); |
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80 | |
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81 | virtual ~G4eCoulombScatteringModel(); |
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82 | |
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83 | virtual void Initialise(const G4ParticleDefinition*, const G4DataVector&); |
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84 | |
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85 | virtual G4double ComputeCrossSectionPerAtom( |
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86 | const G4ParticleDefinition*, |
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87 | G4double kinEnergy, |
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88 | G4double Z, |
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89 | G4double A, |
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90 | G4double cut, |
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91 | G4double emax); |
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92 | |
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93 | virtual void SampleSecondaries(std::vector<G4DynamicParticle*>*, |
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94 | const G4MaterialCutsCouple*, |
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95 | const G4DynamicParticle*, |
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96 | G4double tmin, |
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97 | G4double maxEnergy); |
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98 | |
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99 | protected: |
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100 | |
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101 | G4double ComputeElectronXSectionPerAtom( |
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102 | const G4ParticleDefinition*, |
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103 | G4double kinEnergy, |
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104 | G4double Z, |
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105 | G4double A, |
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106 | G4double cut); |
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107 | |
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108 | virtual G4double CalculateCrossSectionPerAtom( |
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109 | const G4ParticleDefinition*, |
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110 | G4double kinEnergy, |
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111 | G4double Z, G4double A); |
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112 | |
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113 | inline void SetupParticle(const G4ParticleDefinition*); |
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114 | |
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115 | inline void SetupKinematic(G4double kinEnergy); |
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116 | |
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117 | inline void SetupTarget(G4double Z, G4double A, G4double kinEnergy); |
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118 | |
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119 | private: |
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120 | |
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121 | // hide assignment operator |
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122 | G4eCoulombScatteringModel & operator=(const G4eCoulombScatteringModel &right); |
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123 | G4eCoulombScatteringModel(const G4eCoulombScatteringModel&); |
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124 | |
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125 | protected: |
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126 | |
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127 | const G4ParticleDefinition* theProton; |
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128 | const G4ParticleDefinition* theElectron; |
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129 | const G4ParticleDefinition* thePositron; |
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130 | |
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131 | G4ParticleChangeForGamma* fParticleChange; |
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132 | G4NistManager* fNistManager; |
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133 | |
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134 | G4double coeff; |
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135 | G4double constn; |
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136 | G4double cosThetaMin; |
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137 | G4double cosThetaMax; |
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138 | G4double cosTetMaxNuc; |
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139 | G4double cosTetMaxElec; |
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140 | G4double q2Limit; |
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141 | G4double elecXSection; |
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142 | G4double nucXSection; |
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143 | G4double ecut; |
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144 | |
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145 | // projectile |
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146 | const G4ParticleDefinition* particle; |
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147 | |
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148 | G4double chargeSquare; |
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149 | G4double spin; |
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150 | G4double mass; |
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151 | G4double tkin; |
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152 | G4double mom2; |
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153 | G4double invbeta2; |
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154 | |
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155 | // target |
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156 | G4double targetZ; |
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157 | G4double targetA; |
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158 | G4double screenZ; |
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159 | G4double formfactA; |
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160 | |
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161 | private: |
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162 | |
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163 | G4PhysicsTable* theCrossSectionTable; |
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164 | |
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165 | G4double a0; |
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166 | G4double lowKEnergy; |
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167 | G4double highKEnergy; |
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168 | G4double alpha2; |
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169 | G4double faclim; |
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170 | |
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171 | G4int nbins; |
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172 | G4int nmax; |
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173 | G4int index[100]; |
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174 | |
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175 | G4bool buildTable; |
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176 | G4bool isInitialised; |
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177 | }; |
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178 | |
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179 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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180 | |
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181 | inline |
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182 | void G4eCoulombScatteringModel::SetupParticle(const G4ParticleDefinition* p) |
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183 | { |
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184 | // Initialise mass and charge |
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185 | if(p != particle) { |
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186 | particle = p; |
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187 | mass = particle->GetPDGMass(); |
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188 | spin = particle->GetPDGSpin(); |
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189 | G4double q = particle->GetPDGCharge()/eplus; |
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190 | chargeSquare = q*q; |
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191 | tkin = 0.0; |
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192 | } |
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193 | } |
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194 | |
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195 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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196 | |
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197 | inline void G4eCoulombScatteringModel::SetupKinematic(G4double ekin) |
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198 | { |
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199 | if(ekin != tkin) { |
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200 | tkin = ekin; |
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201 | mom2 = tkin*(tkin + 2.0*mass); |
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202 | invbeta2 = 1.0 + mass*mass/mom2; |
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203 | } |
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204 | } |
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205 | |
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206 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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207 | |
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208 | inline void G4eCoulombScatteringModel::SetupTarget(G4double Z, G4double A, |
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209 | G4double e) |
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210 | { |
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211 | if(e != tkin || Z != targetZ || A != targetA) { |
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212 | targetZ = Z; |
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213 | targetA = A; |
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214 | SetupKinematic(e); |
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215 | cosTetMaxNuc = std::max(cosThetaMax, 1.0 - 0.5*q2Limit/mom2); |
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216 | G4double x = fNistManager->GetZ13(Z); |
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217 | screenZ = a0*x*x*(1.13 + 3.76*invbeta2*Z*Z*chargeSquare*alpha2)/mom2; |
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218 | if(particle == theProton && A < 1.5 && cosTetMaxNuc < 0.0) |
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219 | cosTetMaxNuc = 0.0; |
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220 | // A.V. Butkevich et al., NIM A 488 (2002) 282 |
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221 | x = fNistManager->GetLOGA(A); |
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222 | formfactA = mom2*constn*std::exp(0.54*x); |
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223 | } |
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224 | } |
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225 | |
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226 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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227 | |
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228 | #endif |
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