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Please see the license in the file LICENSE and URL above * 16 // * for the full disclaimer and the limitation of liability. * 17 // * * 18 // * This code implementation is the result of the scientific and * 19 // * technical work of the GEANT4 collaboration. * 20 // * By using, copying, modifying or distributing the software (or * 21 // * any work based on the software) you agree to acknowledge its * 22 // * use in resulting scientific publications, and indicate your * 23 // * acceptance of all terms of the Geant4 Software license. * 24 // ******************************************************************** 25 // 26 // 27 // 28 // Hadronic Process: Nuclear De-excitations 29 // by V. Lara 30 31 #include "G4StatMF.hh" 32 #include "G4PhysicalConstants.hh" 33 #include "G4SystemOfUnits.hh" 34 #include "G4Pow.hh" 35 #include "G4PhysicsModelCatalog.hh" 36 37 G4StatMF::G4StatMF() 38 { 39 _secID = G4PhysicsModelCatalog::GetModelID("model_G4StatMF"); 40 } 41 42 G4StatMF::~G4StatMF() {} 43 44 G4FragmentVector* G4StatMF::BreakItUp(const G4Fragment &theFragment) 45 { 46 if (theFragment.GetExcitationEnergy() <= 0.0) { 47 return nullptr; 48 } 49 50 // Maximun average multiplicity: M_0 = 2.6 for A ~ 200 51 // and M_0 = 3.3 for A <= 110 52 G4double MaxAverageMultiplicity = 53 G4StatMFParameters::GetMaxAverageMultiplicity(theFragment.GetA_asInt()); 54 55 56 // We'll use two kinds of ensembles 57 G4StatMFMicroCanonical * theMicrocanonicalEnsemble = 0; 58 G4StatMFMacroCanonical * theMacrocanonicalEnsemble = 0; 59 60 //------------------------------------------------------- 61 // Direct simulation part (Microcanonical ensemble) 62 //------------------------------------------------------- 63 64 // Microcanonical ensemble initialization 65 theMicrocanonicalEnsemble = new G4StatMFMicroCanonical(theFragment); 66 67 G4int Iterations = 0; 68 G4int IterationsLimit = 100000; 69 G4double Temperature = 0.0; 70 71 G4bool FirstTime = true; 72 G4StatMFChannel * theChannel = 0; 73 74 G4bool ChannelOk; 75 do { // Try to de-excite as much as IterationLimit permits 76 do { 77 78 G4double theMeanMult = theMicrocanonicalEnsemble->GetMeanMultiplicity(); 79 if (theMeanMult <= MaxAverageMultiplicity) { 80 // G4cout << "MICROCANONICAL" << G4endl; 81 // Choose fragments atomic numbers and charges from direct simulation 82 theChannel = theMicrocanonicalEnsemble->ChooseAandZ(theFragment); 83 _theEnsemble = theMicrocanonicalEnsemble; 84 } else { 85 //----------------------------------------------------- 86 // Non direct simulation part (Macrocanonical Ensemble) 87 //----------------------------------------------------- 88 if (FirstTime) { 89 // Macrocanonical ensemble initialization 90 theMacrocanonicalEnsemble = new G4StatMFMacroCanonical(theFragment); 91 _theEnsemble = theMacrocanonicalEnsemble; 92 FirstTime = false; 93 } 94 // G4cout << "MACROCANONICAL" << G4endl; 95 // Select calculated fragment total multiplicity, 96 // fragment atomic numbers and fragment charges. 97 theChannel = theMacrocanonicalEnsemble->ChooseAandZ(theFragment); 98 } 99 100 ChannelOk = theChannel->CheckFragments(); 101 if (!ChannelOk) delete theChannel; 102 103 // Loop checking, 05-Aug-2015, Vladimir Ivanchenko 104 } while (!ChannelOk); 105 106 107 if (theChannel->GetMultiplicity() <= 1) { 108 G4FragmentVector * theResult = new G4FragmentVector; 109 theResult->push_back(new G4Fragment(theFragment)); 110 delete theMicrocanonicalEnsemble; 111 if (theMacrocanonicalEnsemble != 0) delete theMacrocanonicalEnsemble; 112 delete theChannel; 113 return theResult; 114 } 115 116 //-------------------------------------- 117 // Second part of simulation procedure. 118 //-------------------------------------- 119 120 // Find temperature of breaking channel. 121 Temperature = _theEnsemble->GetMeanTemperature(); // Initial guess for Temperature 122 123 if (FindTemperatureOfBreakingChannel(theFragment,theChannel,Temperature)) break; 124 125 // Do not forget to delete this unusable channel, for which we failed to find the temperature, 126 // otherwise for very proton-reach nuclei it would lead to memory leak due to large 127 // number of iterations. N.B. "theChannel" is created in G4StatMFMacroCanonical::ChooseZ() 128 129 // G4cout << " Iteration # " << Iterations << " Mean Temperature = " << Temperature << G4endl; 130 131 delete theChannel; 132 133 // Loop checking, 05-Aug-2015, Vladimir Ivanchenko 134 } while (Iterations++ < IterationsLimit ); 135 136 // If Iterations >= IterationsLimit means that we couldn't solve for temperature 137 if (Iterations >= IterationsLimit) 138 throw G4HadronicException(__FILE__, __LINE__, "G4StatMF::BreakItUp: Was not possible to solve for temperature of breaking channel"); 139 140 G4FragmentVector * theResult = theChannel-> 141 GetFragments(theFragment.GetA_asInt(),theFragment.GetZ_asInt(),Temperature); 142 143 // ~~~~~~ Energy conservation Patch !!!!!!!!!!!!!!!!!!!!!! 144 // Original nucleus 4-momentum in CM system 145 G4LorentzVector InitialMomentum(theFragment.GetMomentum()); 146 InitialMomentum.boost(-InitialMomentum.boostVector()); 147 G4double ScaleFactor = 0.0; 148 G4double SavedScaleFactor = 0.0; 149 do { 150 G4double FragmentsEnergy = 0.0; 151 for (auto const & ptr : *theResult) { 152 FragmentsEnergy += ptr->GetMomentum().e(); 153 } 154 if (0.0 == FragmentsEnergy) { break; } 155 SavedScaleFactor = ScaleFactor; 156 ScaleFactor = InitialMomentum.e()/FragmentsEnergy; 157 G4ThreeVector ScaledMomentum(0.0,0.0,0.0); 158 for (auto const & ptr : *theResult) { 159 ScaledMomentum = ScaleFactor * ptr->GetMomentum().vect(); 160 G4double Mass = ptr->GetMomentum().mag(); 161 G4LorentzVector NewMomentum; 162 NewMomentum.setVect(ScaledMomentum); 163 NewMomentum.setE(std::sqrt(ScaledMomentum.mag2()+Mass*Mass)); 164 ptr->SetMomentum(NewMomentum); 165 } 166 // Loop checking, 05-Aug-2015, Vladimir Ivanchenko 167 } while (ScaleFactor > 1.0+1.e-5 && std::abs(ScaleFactor-SavedScaleFactor)/ScaleFactor > 1.e-10); 168 // ~~~~~~ End of patch !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! 169 170 // Perform Lorentz boost 171 G4FragmentVector::iterator i; 172 for (i = theResult->begin(); i != theResult->end(); i++) { 173 G4LorentzVector FourMom = (*i)->GetMomentum(); 174 FourMom.boost(theFragment.GetMomentum().boostVector()); 175 (*i)->SetMomentum(FourMom); 176 (*i)->SetCreatorModelID(_secID); 177 } 178 179 // garbage collection 180 delete theMicrocanonicalEnsemble; 181 if (theMacrocanonicalEnsemble != 0) delete theMacrocanonicalEnsemble; 182 delete theChannel; 183 184 return theResult; 185 } 186 187 188 G4bool G4StatMF::FindTemperatureOfBreakingChannel(const G4Fragment & theFragment, 189 const G4StatMFChannel * aChannel, 190 G4double & Temperature) 191 // This finds temperature of breaking channel. 192 { 193 G4int A = theFragment.GetA_asInt(); 194 G4int Z = theFragment.GetZ_asInt(); 195 G4double U = theFragment.GetExcitationEnergy(); 196 197 G4double T = std::max(Temperature,0.0012*MeV); 198 G4double Ta = T; 199 G4double TotalEnergy = CalcEnergy(A,Z,aChannel,T); 200 201 G4double Da = (U - TotalEnergy)/U; 202 G4double Db = 0.0; 203 204 // bracketing the solution 205 if (Da == 0.0) { 206 Temperature = T; 207 return true; 208 } else if (Da < 0.0) { 209 do { 210 T *= 0.5; 211 if (T < 0.001*MeV) return false; 212 213 TotalEnergy = CalcEnergy(A,Z,aChannel,T); 214 215 Db = (U - TotalEnergy)/U; 216 // Loop checking, 05-Aug-2015, Vladimir Ivanchenko 217 } while (Db < 0.0); 218 219 } else { 220 do { 221 T *= 1.5; 222 223 TotalEnergy = CalcEnergy(A,Z,aChannel,T); 224 225 Db = (U - TotalEnergy)/U; 226 // Loop checking, 05-Aug-2015, Vladimir Ivanchenko 227 } while (Db > 0.0); 228 } 229 230 G4double eps = 1.0e-14 * std::abs(T-Ta); 231 //G4double eps = 1.0e-3 ; 232 233 // Start the bisection method 234 for (G4int j = 0; j < 1000; j++) { 235 G4double Tc = (Ta+T)*0.5; 236 if (std::abs(Ta-Tc) <= eps) { 237 Temperature = Tc; 238 return true; 239 } 240 241 T = Tc; 242 TotalEnergy = CalcEnergy(A,Z,aChannel,T); 243 G4double Dc = (U - TotalEnergy)/U; 244 245 if (Dc == 0.0) { 246 Temperature = Tc; 247 return true; 248 } 249 if (Da*Dc < 0.0) { 250 T = Tc; 251 Db = Dc; 252 } else { 253 Ta = Tc; 254 Da = Dc; 255 } 256 } 257 258 Temperature = (Ta+T)*0.5; 259 return false; 260 } 261 262 G4double G4StatMF::CalcEnergy(G4int A, G4int Z, const G4StatMFChannel * aChannel, 263 G4double T) 264 { 265 G4double MassExcess0 = G4NucleiProperties::GetMassExcess(A,Z); 266 G4double ChannelEnergy = aChannel->GetFragmentsEnergy(T); 267 return -MassExcess0 + G4StatMFParameters::GetCoulomb() + ChannelEnergy; 268 } 269 270 271 272