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Please see the license in the file LICENSE and URL above * 00016 // * for the full disclaimer and the limitation of liability. * 00017 // * * 00018 // * This code implementation is the result of the scientific and * 00019 // * technical work of the GEANT4 collaboration. * 00020 // * By using, copying, modifying or distributing the software (or * 00021 // * any work based on the software) you agree to acknowledge its * 00022 // * use in resulting scientific publications, and indicate your * 00023 // * acceptance of all terms of the Geant4 Software license. * 00024 // ******************************************************************** 00025 // 00026 // G4RKFieldIntegrator 00027 #include "G4RKFieldIntegrator.hh" 00028 #include "G4PhysicalConstants.hh" 00029 #include "G4SystemOfUnits.hh" 00030 #include "G4NucleiProperties.hh" 00031 #include "G4FermiMomentum.hh" 00032 #include "G4NuclearFermiDensity.hh" 00033 #include "G4NuclearShellModelDensity.hh" 00034 #include "G4Nucleon.hh" 00035 00036 // Class G4RKFieldIntegrator 00037 //************************************************************************************************************************************* 00038 00039 // only theActive are propagated, nothing else 00040 // only theSpectators define the field, nothing else 00041 00042 void G4RKFieldIntegrator::Transport(G4KineticTrackVector &theActive, const G4KineticTrackVector &theSpectators, G4double theTimeStep) 00043 { 00044 (void)theActive; 00045 (void)theSpectators; 00046 (void)theTimeStep; 00047 } 00048 00049 00050 G4double G4RKFieldIntegrator::CalculateTotalEnergy(const G4KineticTrackVector& Barions) 00051 { 00052 const G4double Alpha = 0.25/fermi/fermi; 00053 const G4double t1 = -7264.04*fermi*fermi*fermi; 00054 const G4double tGamma = 87.65*fermi*fermi*fermi*fermi*fermi*fermi; 00055 // const G4double Gamma = 1.676; 00056 const G4double Vo = -0.498*fermi; 00057 const G4double GammaY = 1.4*fermi; 00058 00059 G4double Etot = 0; 00060 G4int nBarion = Barions.size(); 00061 for(G4int c1 = 0; c1 < nBarion; c1++) 00062 { 00063 G4KineticTrack* p1 = Barions.operator[](c1); 00064 // Ekin 00065 Etot += p1->Get4Momentum().e(); 00066 for(G4int c2 = c1 + 1; c2 < nBarion; c2++) 00067 { 00068 G4KineticTrack* p2 = Barions.operator[](c2); 00069 G4double r12 = (p1->GetPosition() - p2->GetPosition()).mag()*fermi; 00070 00071 // Esk2 00072 Etot += t1*std::pow(Alpha/pi, 3/2)*std::exp(-Alpha*r12*r12); 00073 00074 // Eyuk 00075 Etot += Vo*0.5/r12*std::exp(1/(4*Alpha*GammaY*GammaY))* 00076 (std::exp(-r12/GammaY)*(1 - Erf(0.5/GammaY/std::sqrt(Alpha) - std::sqrt(Alpha)*r12)) - 00077 std::exp( r12/GammaY)*(1 - Erf(0.5/GammaY/std::sqrt(Alpha) + std::sqrt(Alpha)*r12))); 00078 00079 // Ecoul 00080 Etot += 1.44*p1->GetDefinition()->GetPDGCharge()*p2->GetDefinition()->GetPDGCharge()/r12*Erf(std::sqrt(Alpha)*r12); 00081 00082 // Epaul 00083 Etot = 0; 00084 00085 for(G4int c3 = c2 + 1; c3 < nBarion; c3++) 00086 { 00087 G4KineticTrack* p3 = Barions.operator[](c3); 00088 G4double r13 = (p1->GetPosition() - p3->GetPosition()).mag()*fermi; 00089 00090 // Esk3 00091 Etot = tGamma*std::pow(4*Alpha*Alpha/3/pi/pi, 1.5)*std::exp(-Alpha*(r12*r12 + r13*r13)); 00092 } 00093 } 00094 } 00095 return Etot; 00096 } 00097 00098 //************************************************************************************************ 00099 // originated from the Numerical recipes error function 00100 G4double G4RKFieldIntegrator::Erf(G4double X) 00101 { 00102 const G4double Z1 = 1; 00103 const G4double HF = Z1/2; 00104 const G4double C1 = 0.56418958; 00105 00106 const G4double P10 = +3.6767877; 00107 const G4double Q10 = +3.2584593; 00108 const G4double P11 = -9.7970465E-2; 00109 00110 static G4double P2[5] = { 7.3738883, 6.8650185, 3.0317993, 0.56316962, 4.3187787e-5 }; 00111 static G4double Q2[5] = { 7.3739609, 15.184908, 12.79553, 5.3542168, 1. }; 00112 00113 const G4double P30 = -1.2436854E-1; 00114 const G4double Q30 = +4.4091706E-1; 00115 const G4double P31 = -9.6821036E-2; 00116 00117 G4double V = std::abs(X); 00118 G4double H; 00119 G4double Y; 00120 G4int c1; 00121 00122 if(V < HF) 00123 { 00124 Y = V*V; 00125 H = X*(P10 + P11*Y)/(Q10+Y); 00126 } 00127 else 00128 { 00129 if(V < 4) 00130 { 00131 G4double AP = P2[4]; 00132 G4double AQ = Q2[4]; 00133 for(c1 = 3; c1 >= 0; c1--) 00134 { 00135 AP = P2[c1] + V*AP; 00136 AQ = Q2[c1] + V*AQ; 00137 } 00138 H = 1 - std::exp(-V*V)*AP/AQ; 00139 } 00140 else 00141 { 00142 Y = 1./V*V; 00143 H = 1 - std::exp(-V*V)*(C1+Y*(P30 + P31*Y)/(Q30 + Y))/V; 00144 } 00145 if (X < 0) 00146 H = -H; 00147 } 00148 return H; 00149 } 00150 00151 //************************************************************************************************ 00152 //This is a QMD version to calculate excitation energy of a fragment, 00153 //which consists from G4KTV &the Particles 00154 /* 00155 G4double G4RKFieldIntegrator::GetExcitationEnergy(const G4KineticTrackVector &theParticles) 00156 { 00157 // Excitation energy of a fragment consisting from A nucleons and Z protons 00158 // is Etot - Z*Mp - (A - Z)*Mn - B(A, Z), where B(A,Z) is the binding energy of fragment 00159 // and Mp, Mn are proton and neutron mass, respectively. 00160 G4int NZ = 0; 00161 G4int NA = 0; 00162 G4double Etot = CalculateTotalEnergy(theParticles); 00163 for(G4int cParticle = 0; cParticle < theParticles.length(); cParticle++) 00164 { 00165 G4KineticTrack* pKineticTrack = theParticles.at(cParticle); 00166 G4int Encoding = std::abs(pKineticTrack->GetDefinition()->GetPDGEncoding()); 00167 if (Encoding == 2212) 00168 NZ++, NA++; 00169 if (Encoding == 2112) 00170 NA++; 00171 Etot -= pKineticTrack->GetDefinition()->GetPDGMass(); 00172 } 00173 return Etot - G4NucleiProperties::GetBindingEnergy(NZ, NA); 00174 } 00175 */ 00176 00177 //************************************************************************************************************************************* 00178 //This is a simplified method to get excitation energy of a residual 00179 // nucleus with nHitNucleons. 00180 G4double G4RKFieldIntegrator::GetExcitationEnergy(G4int nHitNucleons, const G4KineticTrackVector &) 00181 { 00182 const G4double MeanE = 50; 00183 G4double Sum = 0; 00184 for(G4int c1 = 0; c1 < nHitNucleons; c1++) 00185 { 00186 Sum += -MeanE*std::log(G4UniformRand()); 00187 } 00188 return Sum; 00189 } 00190 //************************************************************************************************************************************* 00191 00192 /* 00193 //This is free propagation of particles for CASCADE mode. Target nucleons should be frozen 00194 void G4RKFieldIntegrator::Integrate(G4KineticTrackVector& theParticles) 00195 { 00196 for(G4int cParticle = 0; cParticle < theParticles.length(); cParticle++) 00197 { 00198 G4KineticTrack* pKineticTrack = theParticles.at(cParticle); 00199 pKineticTrack->SetPosition(pKineticTrack->GetPosition() + theTimeStep*pKineticTrack->Get4Momentum().boostVector()); 00200 } 00201 } 00202 */ 00203 //************************************************************************************************************************************* 00204 00205 void G4RKFieldIntegrator::Integrate(const G4KineticTrackVector& theBarions, G4double theTimeStep) 00206 { 00207 for(size_t cParticle = 0; cParticle < theBarions.size(); cParticle++) 00208 { 00209 G4KineticTrack* pKineticTrack = theBarions[cParticle]; 00210 pKineticTrack->SetPosition(pKineticTrack->GetPosition() + theTimeStep*pKineticTrack->Get4Momentum().boostVector()); 00211 } 00212 } 00213 00214 //************************************************************************************************************************************* 00215 00216 // constant to calculate theCoulomb barrier 00217 const G4double G4RKFieldIntegrator::coulomb = 1.44 / 1.14 * MeV; 00218 00219 // kaon's potential constant (real part only) 00220 // 0.35 + i0.82 or 0.63 + i0.89 fermi 00221 const G4double G4RKFieldIntegrator::a_kaon = 0.35; 00222 00223 // pion's potential constant (real part only) 00225 // 0.35 + i0.82 or 0.63 + i0.89 fermi 00226 const G4double G4RKFieldIntegrator::a_pion = 0.35; 00227 00228 // antiproton's potential constant (real part only) 00229 // 1.53 + i2.50 fermi 00230 const G4double G4RKFieldIntegrator::a_antiproton = 1.53; 00231 00232 // methods for calculating potentials for different types of particles 00233 // aPosition is relative to the nucleus center 00234 G4double G4RKFieldIntegrator::GetNeutronPotential(G4double ) 00235 { 00236 /* 00237 const G4double Mn = 939.56563 * MeV; // mass of nuetron 00238 00239 G4VNuclearDensity *theDencity; 00240 if(theA < 17) theDencity = new G4NuclearShellModelDensity(theA, theZ); 00241 else theDencity = new G4NuclearFermiDensity(theA, theZ); 00242 00243 // GetDencity() accepts only G4ThreeVector so build it: 00244 G4ThreeVector aPosition(0.0, 0.0, radius); 00245 G4double density = theDencity->GetDensity(aPosition); 00246 delete theDencity; 00247 00248 G4FermiMomentum *fm = new G4FermiMomentum(); 00249 fm->Init(theA, theZ); 00250 G4double fermiMomentum = fm->GetFermiMomentum(density); 00251 delete fm; 00252 00253 return sqr(fermiMomentum)/(2 * Mn) 00254 + G4CreateNucleus::GetBindingEnergy(theZ, theA)/theA; 00255 //+ G4NucleiProperties::GetBindingEnergy(theZ, theA)/theA; 00256 */ 00257 00258 return 0.0; 00259 } 00260 00261 G4double G4RKFieldIntegrator::GetProtonPotential(G4double ) 00262 { 00263 /* 00264 // calculate Coulomb barrier value 00265 G4double theCoulombBarrier = coulomb * theZ/(1. + std::pow(theA, 1./3.)); 00266 const G4double Mp = 938.27231 * MeV; // mass of proton 00267 00268 G4VNuclearDensity *theDencity; 00269 if(theA < 17) theDencity = new G4NuclearShellModelDensity(theA, theZ); 00270 else theDencity = new G4NuclearFermiDensity(theA, theZ); 00271 00272 // GetDencity() accepts only G4ThreeVector so build it: 00273 G4ThreeVector aPosition(0.0, 0.0, radius); 00274 G4double density = theDencity->GetDensity(aPosition); 00275 delete theDencity; 00276 00277 G4FermiMomentum *fm = new G4FermiMomentum(); 00278 fm->Init(theA, theZ); 00279 G4double fermiMomentum = fm->GetFermiMomentum(density); 00280 delete fm; 00281 00282 return sqr(fermiMomentum)/ (2 * Mp) 00283 + G4CreateNucleus::GetBindingEnergy(theZ, theA)/theA; 00284 //+ G4NucleiProperties::GetBindingEnergy(theZ, theA)/theA 00285 + theCoulombBarrier; 00286 */ 00287 00288 return 0.0; 00289 } 00290 00291 G4double G4RKFieldIntegrator::GetAntiprotonPotential(G4double ) 00292 { 00293 /* 00294 //G4double theM = G4NucleiProperties::GetAtomicMass(theA, theZ); 00295 G4double theM = theZ * G4Proton::Proton()->GetPDGMass() 00296 + (theA - theZ) * G4Neutron::Neutron()->GetPDGMass() 00297 + G4CreateNucleus::GetBindingEnergy(theZ, theA); 00298 00299 const G4double Mp = 938.27231 * MeV; // mass of proton 00300 G4double mu = (theM * Mp)/(theM + Mp); 00301 00302 // antiproton's potential coefficient 00303 // V = coeff_antiproton * nucleus_density 00304 G4double coeff_antiproton = -2.*pi/mu * (1. + Mp) * a_antiproton; 00305 00306 G4VNuclearDensity *theDencity; 00307 if(theA < 17) theDencity = new G4NuclearShellModelDensity(theA, theZ); 00308 else theDencity = new G4NuclearFermiDensity(theA, theZ); 00309 00310 // GetDencity() accepts only G4ThreeVector so build it: 00311 G4ThreeVector aPosition(0.0, 0.0, radius); 00312 G4double density = theDencity->GetDensity(aPosition); 00313 delete theDencity; 00314 00315 return coeff_antiproton * density; 00316 */ 00317 00318 return 0.0; 00319 } 00320 00321 G4double G4RKFieldIntegrator::GetKaonPotential(G4double ) 00322 { 00323 /* 00324 //G4double theM = G4NucleiProperties::GetAtomicMass(theA, theZ); 00325 G4double theM = theZ * G4Proton::Proton()->GetPDGMass() 00326 + (theA - theZ) * G4Neutron::Neutron()->GetPDGMass() 00327 + G4CreateNucleus::GetBindingEnergy(theZ, theA); 00328 00329 const G4double Mk = 496. * MeV; // mass of "kaon" 00330 G4double mu = (theM * Mk)/(theM + Mk); 00331 00332 // kaon's potential coefficient 00333 // V = coeff_kaon * nucleus_density 00334 G4double coeff_kaon = -2.*pi/mu * (1. + Mk/theM) * a_kaon; 00335 00336 G4VNuclearDensity *theDencity; 00337 if(theA < 17) theDencity = new G4NuclearShellModelDensity(theA, theZ); 00338 else theDencity = new G4NuclearFermiDensity(theA, theZ); 00339 00340 // GetDencity() accepts only G4ThreeVector so build it: 00341 G4ThreeVector aPosition(0.0, 0.0, radius); 00342 G4double density = theDencity->GetDensity(aPosition); 00343 delete theDencity; 00344 00345 return coeff_kaon * density; 00346 */ 00347 00348 return 0.0; 00349 } 00350 00351 G4double G4RKFieldIntegrator::GetPionPotential(G4double ) 00352 { 00353 /* 00354 //G4double theM = G4NucleiProperties::GetAtomicMass(theA, theZ); 00355 G4double theM = theZ * G4Proton::Proton()->GetPDGMass() 00356 + (theA - theZ) * G4Neutron::Neutron()->GetPDGMass() 00357 + G4CreateNucleus::GetBindingEnergy(theZ, theA); 00358 00359 const G4double Mpi = 139. * MeV; // mass of "pion" 00360 G4double mu = (theM * Mpi)/(theM + Mpi); 00361 00362 // pion's potential coefficient 00363 // V = coeff_pion * nucleus_density 00364 G4double coeff_pion = -2.*pi/mu * (1. + Mpi) * a_pion; 00365 00366 G4VNuclearDensity *theDencity; 00367 if(theA < 17) theDencity = new G4NuclearShellModelDensity(theA, theZ); 00368 else theDencity = new G4NuclearFermiDensity(theA, theZ); 00369 00370 // GetDencity() accepts only G4ThreeVector so build it: 00371 G4ThreeVector aPosition(0.0, 0.0, radius); 00372 G4double density = theDencity->GetDensity(aPosition); 00373 delete theDencity; 00374 00375 return coeff_pion * density; 00376 */ 00377 00378 return 0.0; 00379 }