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35 // 35 //
36 // %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 36 // %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
37 // 37 //
38 // MODULE: G4EMDissociationCrossSection.cc 38 // MODULE: G4EMDissociationCrossSection.cc
39 // 39 //
40 // Version: B.1 40 // Version: B.1
41 // Date: 15/04/04 41 // Date: 15/04/04
42 // Author: P R Truscott 42 // Author: P R Truscott
43 // Organisation: QinetiQ Ltd, UK 43 // Organisation: QinetiQ Ltd, UK
44 // Customer: ESA/ESTEC, NOORDWIJK 44 // Customer: ESA/ESTEC, NOORDWIJK
45 // Contract: 17191/03/NL/LvH 45 // Contract: 17191/03/NL/LvH
46 // 46 //
47 // %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 47 // %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
48 // 48 //
49 // CHANGE HISTORY 49 // CHANGE HISTORY
50 // -------------- 50 // --------------
51 // 51 //
52 // 17 October 2003, P R Truscott, QinetiQ Ltd, 52 // 17 October 2003, P R Truscott, QinetiQ Ltd, UK
53 // Created. 53 // Created.
54 // 54 //
55 // 15 March 2004, P R Truscott, QinetiQ Ltd, U 55 // 15 March 2004, P R Truscott, QinetiQ Ltd, UK
56 // Beta release 56 // Beta release
57 // 57 //
58 // 30 May 2005, J.P. Wellisch removed a compil 58 // 30 May 2005, J.P. Wellisch removed a compilation warning on gcc 3.4 for
59 // geant4 7.1. 59 // geant4 7.1.
60 // 09 November 2010, V.Ivanchenko make class a 60 // 09 November 2010, V.Ivanchenko make class applicable for Hydrogen but
61 // set cross section for Hyd 61 // set cross section for Hydrogen to zero
62 // 62 //
63 // 17 August 2011, V.Ivanchenko, provide migra <<
64 // sections considering this c <<
65 // <<
66 // %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 63 // %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
67 ////////////////////////////////////////////// 64 //////////////////////////////////////////////////////////////////////////////
68 // 65 //
69 #include "G4EMDissociationCrossSection.hh" 66 #include "G4EMDissociationCrossSection.hh"
70 #include "G4PhysicalConstants.hh" << 67 #include "G4PhysicsFreeVector.hh"
71 #include "G4SystemOfUnits.hh" <<
72 #include "G4ParticleTable.hh" 68 #include "G4ParticleTable.hh"
73 #include "G4IonTable.hh" 69 #include "G4IonTable.hh"
74 #include "G4HadTmpUtil.hh" 70 #include "G4HadTmpUtil.hh"
75 #include "globals.hh" 71 #include "globals.hh"
76 #include "G4NistManager.hh" <<
77 72
78 73
79 G4EMDissociationCrossSection::G4EMDissociation 74 G4EMDissociationCrossSection::G4EMDissociationCrossSection ()
80 : G4VCrossSectionDataSet("Electromagnetic dis <<
81 { 75 {
82 // This function makes use of the class whic << 76 //
83 // spectrum, G4EMDissociationSpectrum. << 77 // This function makes use of the class which can sample the virtual photon
84 << 78 // spectrum, G4EMDissociationSpectrum.
>> 79 //
85 thePhotonSpectrum = new G4EMDissociationSpec 80 thePhotonSpectrum = new G4EMDissociationSpectrum();
86 << 81 //
87 // Define other constants. << 82 //
88 << 83 // Define other constants.
>> 84 //
89 r0 = 1.18 * fermi; 85 r0 = 1.18 * fermi;
90 J = 36.8 * MeV; 86 J = 36.8 * MeV;
91 Qprime = 17.0 * MeV; 87 Qprime = 17.0 * MeV;
92 epsilon = 0.0768; 88 epsilon = 0.0768;
93 xd = 0.25; 89 xd = 0.25;
94 } 90 }
95 <<
96 ////////////////////////////////////////////// 91 //////////////////////////////////////////////////////////////////////////////
97 << 92 //
98 G4EMDissociationCrossSection::~G4EMDissociatio 93 G4EMDissociationCrossSection::~G4EMDissociationCrossSection()
99 { 94 {
100 delete thePhotonSpectrum; 95 delete thePhotonSpectrum;
101 } 96 }
102 ////////////////////////////////////////////// 97 /////////////////////////////////////////////////////////////////////////////
103 // 98 //
104 G4bool 99 G4bool
105 G4EMDissociationCrossSection::IsElementApplica << 100 G4EMDissociationCrossSection::IsIsoApplicable(const G4DynamicParticle* theDynamicParticle,
106 G4int /*ZZ*/, const G4Material*) << 101 G4int /*ZZ*/, G4int/* AA*/)
107 { 102 {
108 // 103 //
109 // The condition for the applicability of this 104 // The condition for the applicability of this class is that the projectile
110 // must be an ion and the target must have mor 105 // must be an ion and the target must have more than one nucleon. In reality
111 // the value of A for either the projectile or 106 // the value of A for either the projectile or target could be much higher,
112 // since for cases where both he projectile an 107 // since for cases where both he projectile and target are medium to small
113 // Z, the probability of the EMD process is, I 108 // Z, the probability of the EMD process is, I think, VERY small.
114 // 109 //
115 if (G4ParticleTable::GetParticleTable()->Get << 110 if (G4ParticleTable::GetParticleTable()->GetIonTable()->
>> 111 IsIon(theDynamicParticle->GetDefinition()) /*&& AA > 1*/)
116 return true; 112 return true;
117 } else { << 113 else
118 return false; 114 return false;
119 } << 115 }
>> 116
>> 117 G4bool G4EMDissociationCrossSection::IsApplicable
>> 118 (const G4DynamicParticle* theDynamicParticle, const G4Element* theElement)
>> 119 {
>> 120 return IsIsoApplicable(theDynamicParticle, 0, G4lrint(theElement->GetN()));
120 } 121 }
121 122
122 ////////////////////////////////////////////// 123 //////////////////////////////////////////////////////////////////////////////
123 // 124 //
124 G4double G4EMDissociationCrossSection::GetElem << 125 G4double G4EMDissociationCrossSection::GetCrossSection
125 (const G4DynamicParticle* theDynamicParticle << 126 (const G4DynamicParticle* theDynamicParticle, const G4Element* theElement,
126 const G4Material*) << 127 G4double temperature)
>> 128 {
>> 129 G4int nIso = theElement->GetNumberOfIsotopes();
>> 130 G4double crossSection = 0;
>> 131
>> 132 // VI protection for Hydrogen
>> 133 if(theElement->GetZ() < 1.5) { return crossSection; }
>> 134
>> 135 if (nIso) {
>> 136 G4double sig;
>> 137 G4IsotopeVector* isoVector = theElement->GetIsotopeVector();
>> 138 G4double* abundVector = theElement->GetRelativeAbundanceVector();
>> 139 G4int ZZ;
>> 140 G4int AA;
>> 141
>> 142 for (G4int i = 0; i < nIso; i++) {
>> 143 ZZ = (*isoVector)[i]->GetZ();
>> 144 AA = (*isoVector)[i]->GetN();
>> 145 sig = GetZandACrossSection(theDynamicParticle, ZZ, AA, temperature);
>> 146 crossSection += sig*abundVector[i];
>> 147 }
>> 148
>> 149 } else {
>> 150 G4int ZZ = G4lrint(theElement->GetZ());
>> 151 G4int AA = G4lrint(theElement->GetN());
>> 152 crossSection = GetZandACrossSection(theDynamicParticle, ZZ, AA, temperature);
>> 153 }
>> 154
>> 155 return crossSection;
>> 156 }
>> 157
>> 158
>> 159 G4double
>> 160 G4EMDissociationCrossSection::GetZandACrossSection(const G4DynamicParticle *theDynamicParticle,
>> 161 G4int ZZ, G4int AA, G4double /*temperature*/)
127 { 162 {
128 // VI protection for Hydrogen 163 // VI protection for Hydrogen
129 if(1 >= Z) { return 0.0; } << 164 if(ZZ <= 1) { return 0.0; }
130 165
131 // Zero cross-section for particles with kin << 166 //
132 // possible abort signal from bad arithmetic << 167 // Get relevant information about the projectile and target (A, Z) and
133 if ( theDynamicParticle->GetKineticEnergy() << 168 // velocity of the projectile.
134 << 169 //
135 // << 170 G4ParticleDefinition *definitionP = theDynamicParticle->GetDefinition();
136 // Get relevant information about the projec <<
137 // velocity of the projectile. <<
138 // <<
139 const G4ParticleDefinition *definitionP = th <<
140 G4double AP = definitionP->GetBaryonNumber 171 G4double AP = definitionP->GetBaryonNumber();
141 G4double ZP = definitionP->GetPDGCharge(); 172 G4double ZP = definitionP->GetPDGCharge();
142 G4double b = theDynamicParticle->GetBeta( << 173 G4double b = theDynamicParticle->Get4Momentum().beta();
143 if (b <= 0.0 && b >= 1.0) { return 0.0; } << 174 // G4double bsq = b * b;
144 175
145 G4double AT = G4NistManager::Instance()->G << 176 G4double AT = AA;
146 G4double ZT = (G4double)Z; << 177 G4double ZT = ZZ;
147 G4double bmin = thePhotonSpectrum->GetCloses 178 G4double bmin = thePhotonSpectrum->GetClosestApproach(AP, ZP, AT, ZT, b);
148 // << 179 //
149 // << 180 //
150 // Calculate the cross-section for the proje << 181 // Calculate the cross-section for the projectile and then the target. The
151 // information is returned in a G4PhysicsFre << 182 // information is returned in a G4PhysicsFreeVector, which separates out the
152 // cross-sections for the E1 and E2 moments << 183 // cross-sections for the E1 and E2 moments of the virtual photon field, and
153 // the energies (GDR and GQR). << 184 // the energies (GDR and GQR).
154 // << 185 //
155 G4PhysicsFreeVector *theProjectileCrossSecti << 186 G4PhysicsFreeVector *theProjectileCrossSections =
156 GetCrossSectionForProjectile (AP, ZP, AT, 187 GetCrossSectionForProjectile (AP, ZP, AT, ZT, b, bmin);
157 G4double crossSection = 188 G4double crossSection =
158 (*theProjectileCrossSections)[0]+(*theProj 189 (*theProjectileCrossSections)[0]+(*theProjectileCrossSections)[1];
159 delete theProjectileCrossSections; 190 delete theProjectileCrossSections;
160 G4PhysicsFreeVector *theTargetCrossSections << 191 G4PhysicsFreeVector *theTargetCrossSections =
161 GetCrossSectionForTarget (AP, ZP, AT, ZT, 192 GetCrossSectionForTarget (AP, ZP, AT, ZT, b, bmin);
162 crossSection += << 193 crossSection +=
163 (*theTargetCrossSections)[0]+(*theTargetCr 194 (*theTargetCrossSections)[0]+(*theTargetCrossSections)[1];
164 delete theTargetCrossSections; 195 delete theTargetCrossSections;
>> 196
165 return crossSection; 197 return crossSection;
166 } 198 }
167 ////////////////////////////////////////////// 199 ////////////////////////////////////////////////////////////////////////////////
168 // 200 //
169 G4PhysicsFreeVector * 201 G4PhysicsFreeVector *
170 G4EMDissociationCrossSection::GetCrossSectionF << 202 G4EMDissociationCrossSection::GetCrossSectionForProjectile (G4double AP,
171 G4double ZP, G4double /* AT */, G4double ZT, 203 G4double ZP, G4double /* AT */, G4double ZT, G4double b, G4double bmin)
172 { 204 {
173 // 205 //
174 // 206 //
175 // Use Wilson et al's approach to calculate th 207 // Use Wilson et al's approach to calculate the cross-sections due to the E1
176 // and E2 moments of the field at the giant di 208 // and E2 moments of the field at the giant dipole and quadrupole resonances
177 // respectively, Note that the algorithm is t 209 // respectively, Note that the algorithm is traditionally applied to the
178 // EMD break-up of the projectile in the field 210 // EMD break-up of the projectile in the field of the target, as is implemented
179 // here. 211 // here.
180 // 212 //
181 // Initialise variables and calculate the ener 213 // Initialise variables and calculate the energies for the GDR and GQR.
182 // 214 //
183 G4double AProot3 = G4Pow::GetInstance()->A13 << 215 G4double AProot3 = std::pow(AP,1.0/3.0);
184 G4double u = 3.0 * J / Qprime / AProot 216 G4double u = 3.0 * J / Qprime / AProot3;
185 G4double R0 = r0 * AProot3; 217 G4double R0 = r0 * AProot3;
186 G4double E_GDR = hbarc / std::sqrt(0.7*amu_ 218 G4double E_GDR = hbarc / std::sqrt(0.7*amu_c2*R0*R0/8.0/J*
187 (1.0 + u - (1.0 + epsilon + 3.0*u)/(1.0 + 219 (1.0 + u - (1.0 + epsilon + 3.0*u)/(1.0 + epsilon + u)*epsilon));
188 G4double E_GQR = 63.0 * MeV / AProot3; 220 G4double E_GQR = 63.0 * MeV / AProot3;
189 // 221 //
190 // 222 //
191 // Determine the virtual photon spectra at the 223 // Determine the virtual photon spectra at these energies.
192 // 224 //
193 G4double ZTsq = ZT * ZT; 225 G4double ZTsq = ZT * ZT;
194 G4double nE1 = ZTsq * 226 G4double nE1 = ZTsq *
195 thePhotonSpectrum->GetGeneralE1Spectrum(E_ 227 thePhotonSpectrum->GetGeneralE1Spectrum(E_GDR, b, bmin);
196 G4double nE2 = ZTsq * 228 G4double nE2 = ZTsq *
197 thePhotonSpectrum->GetGeneralE2Spectrum(E_ 229 thePhotonSpectrum->GetGeneralE2Spectrum(E_GQR, b, bmin);
198 // 230 //
199 // 231 //
200 // Now calculate the cross-section of the proj 232 // Now calculate the cross-section of the projectile for interaction with the
201 // E1 and E2 fields. 233 // E1 and E2 fields.
202 // 234 //
203 G4double sE1 = 60.0 * millibarn * MeV * (AP- 235 G4double sE1 = 60.0 * millibarn * MeV * (AP-ZP)*ZP/AP;
204 G4double sE2 = 0.22 * microbarn / MeV * ZP * 236 G4double sE2 = 0.22 * microbarn / MeV * ZP * AProot3 * AProot3;
205 if (AP > 100.0) sE2 *= 0.9; 237 if (AP > 100.0) sE2 *= 0.9;
206 else if (AP > 40.0) sE2 *= 0.6; 238 else if (AP > 40.0) sE2 *= 0.6;
207 else sE2 *= 0.3; 239 else sE2 *= 0.3;
208 // 240 //
209 // 241 //
210 // ... and multiply with the intensity of the 242 // ... and multiply with the intensity of the virtual photon spectra to get
211 // the probability of interaction. 243 // the probability of interaction.
212 // 244 //
213 G4PhysicsFreeVector *theCrossSectionVector = 245 G4PhysicsFreeVector *theCrossSectionVector = new G4PhysicsFreeVector(2);
214 theCrossSectionVector->PutValue(0, E_GDR, sE 246 theCrossSectionVector->PutValue(0, E_GDR, sE1*nE1);
215 theCrossSectionVector->PutValue(1, E_GQR, sE 247 theCrossSectionVector->PutValue(1, E_GQR, sE2*nE2*E_GQR*E_GQR);
216 << 248
217 return theCrossSectionVector; 249 return theCrossSectionVector;
218 } 250 }
219 251
220 ////////////////////////////////////////////// 252 ////////////////////////////////////////////////////////////////////////////////
221 // 253 //
222 G4PhysicsFreeVector * 254 G4PhysicsFreeVector *
223 G4EMDissociationCrossSection::GetCrossSectionF << 255 G4EMDissociationCrossSection::GetCrossSectionForTarget (G4double AP,
224 G4double ZP, G4double AT, G4double ZT, G4dou 256 G4double ZP, G4double AT, G4double ZT, G4double b, G4double bmin)
225 { 257 {
226 // 258 //
227 // This is a cheaky little member function to 259 // This is a cheaky little member function to calculate the probability of
228 // EMD for the target in the field of the proj 260 // EMD for the target in the field of the projectile ... just by reversing the
229 // A and Z's for the participants. 261 // A and Z's for the participants.
230 // 262 //
231 return GetCrossSectionForProjectile (AT, ZT, 263 return GetCrossSectionForProjectile (AT, ZT, AP, ZP, b, bmin);
232 } 264 }
233 265
234 ////////////////////////////////////////////// << 266
235 // <<
236 G4double 267 G4double
237 G4EMDissociationCrossSection::GetWilsonProbabi 268 G4EMDissociationCrossSection::GetWilsonProbabilityForProtonDissociation(G4double A,
238 269 G4double Z)
239 { 270 {
240 // 271 //
241 // This is a simple algorithm to choose whethe 272 // This is a simple algorithm to choose whether a proton or neutron is ejected
242 // from the nucleus in the EMD interaction. 273 // from the nucleus in the EMD interaction.
243 // 274 //
244 G4double p = 0.0; 275 G4double p = 0.0;
245 if (Z < 2.0) << 276 if (Z < 6.0)
246 p = 0.0; // To avoid to remove one proton <<
247 else if (Z < 6.0) <<
248 p = 0.5; 277 p = 0.5;
249 else if (Z < 8.0) 278 else if (Z < 8.0)
250 p = 0.6; 279 p = 0.6;
251 else if (Z < 14.0) 280 else if (Z < 14.0)
252 p = 0.7; 281 p = 0.7;
253 else 282 else
254 { 283 {
255 G4double p1 = (G4double) Z / (G4double) A; 284 G4double p1 = (G4double) Z / (G4double) A;
256 G4double p2 = 1.95*G4Exp(-0.075*Z); << 285 G4double p2 = 1.95*std::exp(-0.075*Z);
257 if (p1 < p2) p = p1; 286 if (p1 < p2) p = p1;
258 else p = p2; 287 else p = p2;
259 } 288 }
260 289
261 return p; 290 return p;
262 } 291 }
263 292