[819] | 1 | // |
---|
| 2 | // ******************************************************************** |
---|
| 3 | // * License and Disclaimer * |
---|
| 4 | // * * |
---|
| 5 | // * The Geant4 software is copyright of the Copyright Holders of * |
---|
| 6 | // * the Geant4 Collaboration. It is provided under the terms and * |
---|
| 7 | // * conditions of the Geant4 Software License, included in the file * |
---|
| 8 | // * LICENSE and available at http://cern.ch/geant4/license . These * |
---|
| 9 | // * include a list of copyright holders. * |
---|
| 10 | // * * |
---|
| 11 | // * Neither the authors of this software system, nor their employing * |
---|
| 12 | // * institutes,nor the agencies providing financial support for this * |
---|
| 13 | // * work make any representation or warranty, express or implied, * |
---|
| 14 | // * regarding this software system or assume any liability for its * |
---|
| 15 | // * use. 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 | // |
---|
[962] | 26 | //J.M. Quesada (August2008). Based on: |
---|
[819] | 27 | // |
---|
| 28 | // Hadronic Process: Nuclear De-excitations |
---|
| 29 | // by V. Lara (Oct 1998) |
---|
| 30 | // |
---|
[962] | 31 | // Modif (03 September 2008) by J. M. Quesada for external choice of inverse |
---|
| 32 | // cross section option |
---|
| 33 | // JMQ (06 September 2008) Also external choices have been added for |
---|
| 34 | // superimposed Coulomb barrier (if useSICB is set true, by default is false) |
---|
[1055] | 35 | // |
---|
| 36 | // JMQ (14 february 2009) bug fixed in emission width: hbarc instead of hbar_Planck in the denominator |
---|
| 37 | // |
---|
[962] | 38 | #include <iostream> |
---|
| 39 | using namespace std; |
---|
[819] | 40 | |
---|
| 41 | #include "G4EvaporationProbability.hh" |
---|
| 42 | #include "G4PairingCorrection.hh" |
---|
[1315] | 43 | #include "G4ParticleTable.hh" |
---|
| 44 | #include "G4IonTable.hh" |
---|
[819] | 45 | |
---|
[1347] | 46 | G4EvaporationProbability::G4EvaporationProbability(G4int anA, G4int aZ, |
---|
| 47 | G4double aGamma, |
---|
| 48 | G4VCoulombBarrier * aCoulombBarrier) |
---|
| 49 | : theA(anA), |
---|
| 50 | theZ(aZ), |
---|
| 51 | Gamma(aGamma), |
---|
| 52 | theCoulombBarrierptr(aCoulombBarrier) |
---|
| 53 | {} |
---|
[819] | 54 | |
---|
[1347] | 55 | G4EvaporationProbability::G4EvaporationProbability() |
---|
| 56 | : theA(0), |
---|
| 57 | theZ(0), |
---|
| 58 | Gamma(0.0), |
---|
| 59 | theCoulombBarrierptr(0) |
---|
| 60 | {} |
---|
[819] | 61 | |
---|
[1347] | 62 | G4EvaporationProbability::~G4EvaporationProbability() |
---|
| 63 | {} |
---|
[962] | 64 | |
---|
[1347] | 65 | G4double |
---|
| 66 | G4EvaporationProbability::EmissionProbability(const G4Fragment & fragment, G4double anEnergy) |
---|
[819] | 67 | { |
---|
[1347] | 68 | G4double EmissionProbability = 0.0; |
---|
| 69 | G4double MaximalKineticEnergy = anEnergy; |
---|
[962] | 70 | |
---|
[1347] | 71 | if (MaximalKineticEnergy > 0.0 && fragment.GetExcitationEnergy() > 0.0) { |
---|
| 72 | EmissionProbability = CalculateProbability(fragment, MaximalKineticEnergy); |
---|
[962] | 73 | |
---|
[1347] | 74 | } |
---|
| 75 | return EmissionProbability; |
---|
[819] | 76 | } |
---|
| 77 | |
---|
[962] | 78 | //////////////////////////////////// |
---|
| 79 | |
---|
| 80 | // Computes the integrated probability of evaporation channel |
---|
[1347] | 81 | G4double |
---|
| 82 | G4EvaporationProbability::CalculateProbability(const G4Fragment & fragment, |
---|
| 83 | G4double MaximalKineticEnergy) |
---|
[962] | 84 | { |
---|
[1347] | 85 | G4int ResidualA = fragment.GetA_asInt() - theA; |
---|
| 86 | G4int ResidualZ = fragment.GetZ_asInt() - theZ; |
---|
| 87 | G4double U = fragment.GetExcitationEnergy(); |
---|
[962] | 88 | |
---|
[1347] | 89 | if (OPTxs==0) { |
---|
[962] | 90 | |
---|
[1347] | 91 | G4double NuclearMass = fragment.ComputeGroundStateMass(theZ,theA); |
---|
[819] | 92 | |
---|
[1347] | 93 | G4double delta0 = fPairCorr->GetPairingCorrection(fragment.GetA_asInt(), |
---|
| 94 | fragment.GetZ_asInt()); |
---|
[819] | 95 | |
---|
[1347] | 96 | G4double SystemEntropy = 2.0*std::sqrt( |
---|
| 97 | theEvapLDPptr->LevelDensityParameter(fragment.GetA_asInt(),fragment.GetZ_asInt(),U)* |
---|
| 98 | (U-delta0)); |
---|
[819] | 99 | |
---|
[1347] | 100 | const G4double RN = 1.5*fermi; |
---|
[962] | 101 | |
---|
[819] | 102 | G4double Alpha = CalcAlphaParam(fragment); |
---|
| 103 | G4double Beta = CalcBetaParam(fragment); |
---|
| 104 | |
---|
| 105 | G4double Rmax = MaximalKineticEnergy; |
---|
[1347] | 106 | G4double a = theEvapLDPptr->LevelDensityParameter(ResidualA,ResidualZ,Rmax); |
---|
| 107 | G4double GlobalFactor = Gamma * Alpha/(a*a) * |
---|
| 108 | (NuclearMass*RN*RN*fG4pow->Z23(ResidualA))/ |
---|
| 109 | (twopi* hbar_Planck*hbar_Planck); |
---|
[819] | 110 | G4double Term1 = (2.0*Beta*a-3.0)/2.0 + Rmax*a; |
---|
| 111 | G4double Term2 = (2.0*Beta*a-3.0)*std::sqrt(Rmax*a) + 2.0*a*Rmax; |
---|
| 112 | |
---|
| 113 | G4double ExpTerm1 = 0.0; |
---|
[1347] | 114 | if (SystemEntropy <= 600.0) { ExpTerm1 = std::exp(-SystemEntropy); } |
---|
[819] | 115 | |
---|
| 116 | G4double ExpTerm2 = 2.*std::sqrt(a*Rmax) - SystemEntropy; |
---|
[1347] | 117 | if (ExpTerm2 > 700.0) { ExpTerm2 = 700.0; } |
---|
[819] | 118 | ExpTerm2 = std::exp(ExpTerm2); |
---|
| 119 | |
---|
| 120 | G4double Width = GlobalFactor*(Term1*ExpTerm1 + Term2*ExpTerm2); |
---|
| 121 | |
---|
| 122 | return Width; |
---|
[962] | 123 | |
---|
| 124 | } else if (OPTxs==1 || OPTxs==2 ||OPTxs==3 || OPTxs==4) { |
---|
| 125 | |
---|
[1347] | 126 | G4double EvaporatedMass = fragment.ComputeGroundStateMass(theZ,theA); |
---|
| 127 | G4double ResidulalMass = fragment.ComputeGroundStateMass(ResidualZ,ResidualA); |
---|
| 128 | G4double limit = std::max(0.0,fragment.GetGroundStateMass()-EvaporatedMass-ResidulalMass); |
---|
| 129 | if (useSICB) { |
---|
| 130 | limit = std::max(limit,theCoulombBarrierptr->GetCoulombBarrier(ResidualA,ResidualZ,U)); |
---|
| 131 | } |
---|
[962] | 132 | |
---|
[1347] | 133 | if (MaximalKineticEnergy <= limit) { return 0.0; } |
---|
[962] | 134 | |
---|
[1347] | 135 | // if Coulomb barrier cutoff is superimposed for all cross sections |
---|
| 136 | // then the limit is the Coulomb Barrier |
---|
[1055] | 137 | G4double LowerLimit= limit; |
---|
[962] | 138 | |
---|
[1347] | 139 | //MaximalKineticEnergy: asimptotic value (already accounted for in G4EvaporationChannel) |
---|
[962] | 140 | |
---|
[1055] | 141 | G4double UpperLimit = MaximalKineticEnergy; |
---|
[962] | 142 | |
---|
[1055] | 143 | G4double Width = IntegrateEmissionProbability(fragment,LowerLimit,UpperLimit); |
---|
[962] | 144 | |
---|
[1055] | 145 | return Width; |
---|
[1347] | 146 | } else { |
---|
[962] | 147 | std::ostringstream errOs; |
---|
| 148 | errOs << "Bad option for cross sections at evaporation" <<G4endl; |
---|
| 149 | throw G4HadronicException(__FILE__, __LINE__, errOs.str()); |
---|
| 150 | } |
---|
| 151 | |
---|
[819] | 152 | } |
---|
| 153 | |
---|
[962] | 154 | ///////////////////////////////////////////////////////////////////// |
---|
[819] | 155 | |
---|
[962] | 156 | G4double G4EvaporationProbability:: |
---|
[1347] | 157 | IntegrateEmissionProbability(const G4Fragment & fragment, |
---|
| 158 | const G4double & Low, const G4double & Up ) |
---|
[962] | 159 | { |
---|
| 160 | static const G4int N = 10; |
---|
| 161 | // 10-Points Gauss-Legendre abcisas and weights |
---|
| 162 | static const G4double w[N] = { |
---|
| 163 | 0.0666713443086881, |
---|
| 164 | 0.149451349150581, |
---|
| 165 | 0.219086362515982, |
---|
| 166 | 0.269266719309996, |
---|
| 167 | 0.295524224714753, |
---|
| 168 | 0.295524224714753, |
---|
| 169 | 0.269266719309996, |
---|
| 170 | 0.219086362515982, |
---|
| 171 | 0.149451349150581, |
---|
| 172 | 0.0666713443086881 |
---|
| 173 | }; |
---|
| 174 | static const G4double x[N] = { |
---|
| 175 | -0.973906528517172, |
---|
| 176 | -0.865063366688985, |
---|
| 177 | -0.679409568299024, |
---|
| 178 | -0.433395394129247, |
---|
| 179 | -0.148874338981631, |
---|
| 180 | 0.148874338981631, |
---|
| 181 | 0.433395394129247, |
---|
| 182 | 0.679409568299024, |
---|
| 183 | 0.865063366688985, |
---|
| 184 | 0.973906528517172 |
---|
| 185 | }; |
---|
[819] | 186 | |
---|
[962] | 187 | G4double Total = 0.0; |
---|
| 188 | |
---|
| 189 | |
---|
| 190 | for (G4int i = 0; i < N; i++) |
---|
| 191 | { |
---|
| 192 | |
---|
| 193 | G4double KineticE = ((Up-Low)*x[i]+(Up+Low))/2.0; |
---|
| 194 | |
---|
| 195 | Total += w[i]*ProbabilityDistributionFunction(fragment, KineticE); |
---|
| 196 | |
---|
| 197 | } |
---|
| 198 | Total *= (Up-Low)/2.0; |
---|
| 199 | return Total; |
---|
| 200 | } |
---|
| 201 | |
---|
| 202 | |
---|
| 203 | ///////////////////////////////////////////////////////// |
---|
| 204 | //New method (OPT=1,2,3,4) |
---|
| 205 | |
---|
[1347] | 206 | G4double |
---|
| 207 | G4EvaporationProbability::ProbabilityDistributionFunction( const G4Fragment & fragment, |
---|
| 208 | G4double K) |
---|
[962] | 209 | { |
---|
[1347] | 210 | G4int ResidualA = fragment.GetA_asInt() - theA; |
---|
| 211 | G4int ResidualZ = fragment.GetZ_asInt() - theZ; |
---|
[962] | 212 | G4double U = fragment.GetExcitationEnergy(); |
---|
[1347] | 213 | //G4cout << "### G4EvaporationProbability::ProbabilityDistributionFunction" << G4endl; |
---|
| 214 | //G4cout << "FragZ= " << fragment.GetZ_asInt() << " FragA= " << fragment.GetA_asInt() |
---|
| 215 | // << " Z= " << theZ << " A= " << theA << G4endl; |
---|
| 216 | //G4cout << "PC " << fPairCorr << " DP " << theEvapLDPptr << G4endl; |
---|
[962] | 217 | |
---|
[1347] | 218 | // if(K <= theCoulombBarrierptr->GetCoulombBarrier(ResidualA,ResidualZ,U)) return 0.0; |
---|
[962] | 219 | |
---|
[1347] | 220 | G4double delta1 = fPairCorr->GetPairingCorrection(ResidualA,ResidualZ); |
---|
[962] | 221 | |
---|
[1347] | 222 | G4double delta0 = fPairCorr->GetPairingCorrection(fragment.GetA_asInt(), |
---|
| 223 | fragment.GetZ_asInt()); |
---|
[962] | 224 | |
---|
| 225 | |
---|
[1347] | 226 | G4double ParticleMass = fragment.ComputeGroundStateMass(theZ,theA); |
---|
| 227 | G4double ResidualMass = fragment.ComputeGroundStateMass(ResidualZ,ResidualA); |
---|
[962] | 228 | |
---|
[1347] | 229 | G4double theSeparationEnergy = ParticleMass + ResidualMass |
---|
| 230 | - fragment.GetGroundStateMass(); |
---|
[962] | 231 | |
---|
[1347] | 232 | G4double a0 = theEvapLDPptr->LevelDensityParameter(fragment.GetA_asInt(), |
---|
| 233 | fragment.GetZ_asInt(), |
---|
| 234 | U - delta0); |
---|
[962] | 235 | |
---|
[1347] | 236 | G4double a1 = theEvapLDPptr->LevelDensityParameter(ResidualA, ResidualZ, |
---|
| 237 | U - theSeparationEnergy - delta1); |
---|
[962] | 238 | |
---|
| 239 | |
---|
[1347] | 240 | G4double E0 = U - delta0; |
---|
[962] | 241 | |
---|
[1347] | 242 | G4double E1 = U - theSeparationEnergy - delta1 - K; |
---|
[962] | 243 | |
---|
[1347] | 244 | if (E1<0.) { return 0.; } |
---|
[962] | 245 | |
---|
[1055] | 246 | //JMQ 14/02/09 BUG fixed: hbarc should be in the denominator instead of hbar_Planck |
---|
| 247 | //Without 1/hbar_Panck remains as a width |
---|
[962] | 248 | |
---|
[1055] | 249 | G4double Prob=Gamma*ParticleMass/((pi*hbarc)*(pi*hbarc)*std::exp(2*std::sqrt(a0*E0))) |
---|
| 250 | *K*CrossSection(fragment,K)*std::exp(2*std::sqrt(a1*E1))*millibarn; |
---|
[962] | 251 | |
---|
[1055] | 252 | return Prob; |
---|
[962] | 253 | } |
---|
| 254 | |
---|
| 255 | |
---|