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2 | // ******************************************************************** |
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15 | // * use. Please see the license in the file LICENSE and URL above * |
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24 | // ******************************************************************** |
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25 | // |
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26 | // $Id: G4CoulombScatteringModel.cc,v 1.44 2009/12/03 09:59:07 vnivanch Exp $ |
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27 | // GEANT4 tag $Name: geant4-09-03 $ |
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28 | // |
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29 | // ------------------------------------------------------------------- |
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30 | // |
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31 | // GEANT4 Class file |
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32 | // |
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33 | // |
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34 | // File name: G4CoulombScatteringModel |
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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: 22.08.2005 |
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39 | // |
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40 | // Modifications: |
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41 | // |
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42 | // 01.08.06 V.Ivanchenko extend upper limit of table to TeV and review the |
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43 | // logic of building - only elements from G4ElementTable |
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44 | // 08.08.06 V.Ivanchenko build internal table in ekin scale, introduce faclim |
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45 | // 19.10.06 V.Ivanchenko use inheritance from G4eCoulombScatteringModel |
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46 | // 09.10.07 V.Ivanchenko reorganized methods, add cut dependence in scattering off e- |
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47 | // 09.06.08 V.Ivanchenko SelectIsotope is moved to the base class |
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48 | // 16.06.09 Consolandi rows 109, 111-112, 183, 185-186 |
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49 | // |
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50 | // |
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51 | // Class Description: |
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52 | // |
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53 | // ------------------------------------------------------------------- |
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54 | // |
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55 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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56 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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57 | |
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58 | #include "G4CoulombScatteringModel.hh" |
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59 | #include "Randomize.hh" |
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60 | #include "G4ParticleChangeForGamma.hh" |
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61 | #include "G4ParticleTable.hh" |
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62 | #include "G4IonTable.hh" |
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63 | #include "G4Proton.hh" |
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64 | |
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65 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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66 | |
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67 | using namespace std; |
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68 | |
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69 | G4CoulombScatteringModel::G4CoulombScatteringModel(const G4String& nam) |
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70 | : G4eCoulombScatteringModel(nam) |
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71 | {} |
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72 | |
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73 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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74 | |
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75 | G4CoulombScatteringModel::~G4CoulombScatteringModel() |
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76 | {} |
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77 | |
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78 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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79 | |
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80 | G4double G4CoulombScatteringModel::ComputeCrossSectionPerAtom( |
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81 | const G4ParticleDefinition* p, |
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82 | G4double kinEnergy, |
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83 | G4double Z, |
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84 | G4double, |
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85 | G4double cutEnergy, |
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86 | G4double) |
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87 | { |
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88 | SetupParticle(p); |
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89 | if(kinEnergy < lowEnergyLimit) return 0.0; |
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90 | SetupKinematic(kinEnergy, cutEnergy); |
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91 | |
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92 | // save lab system kinematics |
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93 | G4double xtkin = tkin; |
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94 | G4double xmom2 = mom2; |
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95 | G4double xinvb = invbeta2; |
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96 | |
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97 | // CM system |
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98 | iz = G4int(Z); |
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99 | G4double m2 = fNistManager->GetAtomicMassAmu(iz)*amu_c2; |
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100 | G4double etot = tkin + mass; |
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101 | G4double ptot = sqrt(mom2); |
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102 | |
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103 | G4double m12 = mass*mass; |
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104 | G4double momCM= ptot*m2/sqrt(m12 + m2*m2 + 2.0*etot*m2); |
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105 | |
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106 | mom2 = momCM*momCM; |
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107 | tkin = sqrt(mom2 + m12) - mass; |
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108 | |
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109 | //invbeta2 = 1.0 + m12/mom2; |
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110 | // G4double fm = m2/(mass + m2); |
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111 | |
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112 | // 03.09.2009 C.Consaldi |
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113 | G4double Ecm=sqrt(m12 + m2*m2 + 2.0*etot*m2); |
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114 | G4double mu_rel=mass*m2/Ecm; |
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115 | |
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116 | invbeta2 = 1.0 + mu_rel*mu_rel/mom2; |
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117 | // |
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118 | |
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119 | SetupTarget(Z, tkin); |
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120 | |
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121 | G4double xsec = CrossSectionPerAtom(); |
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122 | |
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123 | // restore Lab system kinematics |
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124 | tkin = xtkin; |
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125 | mom2 = xmom2; |
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126 | invbeta2 = xinvb; |
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127 | |
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128 | return xsec; |
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129 | } |
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130 | |
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131 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
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132 | |
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133 | void G4CoulombScatteringModel::SampleSecondaries( |
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134 | std::vector<G4DynamicParticle*>* fvect, |
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135 | const G4MaterialCutsCouple* couple, |
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136 | const G4DynamicParticle* dp, |
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137 | G4double cutEnergy, |
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138 | G4double) |
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139 | { |
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140 | G4double kinEnergy = dp->GetKineticEnergy(); |
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141 | if(kinEnergy < lowEnergyLimit) return; |
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142 | DefineMaterial(couple); |
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143 | SetupParticle(dp->GetDefinition()); |
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144 | SetupKinematic(kinEnergy, cutEnergy); |
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145 | |
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146 | // Choose nucleus |
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147 | currentElement = SelectRandomAtom(couple,particle, |
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148 | kinEnergy,ecut,kinEnergy); |
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149 | |
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150 | G4double Z = currentElement->GetZ(); |
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151 | iz = G4int(Z); |
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152 | G4int ia = SelectIsotopeNumber(currentElement); |
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153 | G4double m2 = theParticleTable->GetIonTable()->GetNucleusMass(iz, ia); |
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154 | |
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155 | // CM system |
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156 | G4double etot = tkin + mass; |
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157 | G4double ptot = sqrt(mom2); |
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158 | |
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159 | G4double momCM= ptot*m2/sqrt(mass*mass + m2*m2 + 2.0*etot*m2); |
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160 | mom2 = momCM*momCM; |
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161 | G4double m12 = mass*mass; |
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162 | G4double eCM = sqrt(mom2 + m12); |
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163 | |
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164 | // a correction for heavy projectile |
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165 | // G4double fm = m2/(mass + m2); |
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166 | // invbeta2 = 1.0 + m12*fm*fm/mom2; |
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167 | |
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168 | // 03.09.2009 C.Consaldi |
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169 | G4double Ecm=sqrt(m12 + m2*m2 + 2.0*etot*m2); |
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170 | G4double mu_rel=mass*m2/Ecm; |
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171 | |
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172 | invbeta2 = 1.0 + mu_rel*mu_rel/mom2; |
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173 | // |
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174 | |
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175 | // sample scattering angle in CM system |
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176 | SetupTarget(Z, eCM - mass); |
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177 | |
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178 | G4double cost = SampleCosineTheta(); |
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179 | G4double z1 = 1.0 - cost; |
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180 | if(z1 < 0.0) return; |
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181 | G4double sint = sqrt(z1*(1.0 + cost)); |
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182 | G4double phi = twopi * G4UniformRand(); |
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183 | |
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184 | // kinematics in the Lab system |
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185 | G4double bet = ptot/(etot + m2); |
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186 | G4double gam = 1.0/sqrt((1.0 - bet)*(1.0 + bet)); |
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187 | G4double pzCM = momCM*cost; |
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188 | |
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189 | G4ThreeVector v1(momCM*cos(phi)*sint,momCM*sin(phi)*sint,gam*(pzCM + bet*eCM)); |
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190 | G4ThreeVector dir = dp->GetMomentumDirection(); |
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191 | G4ThreeVector newDirection = v1.unit(); |
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192 | newDirection.rotateUz(dir); |
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193 | fParticleChange->ProposeMomentumDirection(newDirection); |
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194 | |
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195 | // G4double elab = gam*(eCM + bet*pzCM); |
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196 | |
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197 | // G4double Ecm = sqrt(mass*mass + m2*m2 + 2.0*etot*m2); |
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198 | G4double elab = etot - m2*(ptot/Ecm)*(ptot/Ecm)*(1.-cost) ; |
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199 | |
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200 | |
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201 | G4double finalT = elab - mass; |
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202 | if(finalT < 0.0) finalT = 0.0; |
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203 | fParticleChange->SetProposedKineticEnergy(finalT); |
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204 | |
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205 | // recoil |
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206 | G4double erec = kinEnergy - finalT; |
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207 | |
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208 | G4double tcut = recoilThreshold; |
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209 | if(pCuts) { tcut= std::max(tcut,(*pCuts)[currentMaterialIndex]); } |
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210 | |
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211 | if(erec > tcut) { |
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212 | G4ParticleDefinition* ion = theParticleTable->FindIon(iz, ia, 0, iz); |
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213 | G4double plab = sqrt(finalT*(finalT + 2.0*mass)); |
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214 | G4ThreeVector p2 = (ptot*dir - plab*newDirection).unit(); |
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215 | G4DynamicParticle* newdp = new G4DynamicParticle(ion, p2, erec); |
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216 | fvect->push_back(newdp); |
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217 | } else if(erec > 0.0) { |
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218 | fParticleChange->ProposeLocalEnergyDeposit(erec); |
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219 | fParticleChange->ProposeNonIonizingEnergyDeposit(erec); |
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220 | } |
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221 | } |
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222 | |
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223 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo...... |
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224 | |
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