| Geant4 Cross Reference |
1 // 1 //
2 // ******************************************* 2 // ********************************************************************
3 // * License and Disclaimer 3 // * License and Disclaimer *
4 // * 4 // * *
5 // * The Geant4 software is copyright of th 5 // * The Geant4 software is copyright of the Copyright Holders of *
6 // * the Geant4 Collaboration. It is provided 6 // * the Geant4 Collaboration. It is provided under the terms and *
7 // * conditions of the Geant4 Software License 7 // * conditions of the Geant4 Software License, included in the file *
8 // * LICENSE and available at http://cern.ch/ 8 // * LICENSE and available at http://cern.ch/geant4/license . These *
9 // * include a list of copyright holders. 9 // * include a list of copyright holders. *
10 // * 10 // * *
11 // * Neither the authors of this software syst 11 // * Neither the authors of this software system, nor their employing *
12 // * institutes,nor the agencies providing fin 12 // * institutes,nor the agencies providing financial support for this *
13 // * work make any representation or warran 13 // * work make any representation or warranty, express or implied, *
14 // * regarding this software system or assum 14 // * regarding this software system or assume any liability for its *
15 // * use. Please see the license in the file 15 // * use. Please see the license in the file LICENSE and URL above *
16 // * for the full disclaimer and the limitatio 16 // * for the full disclaimer and the limitation of liability. *
17 // * 17 // * *
18 // * This code implementation is the result 18 // * This code implementation is the result of the scientific and *
19 // * technical work of the GEANT4 collaboratio 19 // * technical work of the GEANT4 collaboration. *
20 // * 20 // * *
21 // * Parts of this code which have been devel 21 // * Parts of this code which have been developed by QinetiQ Ltd *
22 // * under contract to the European Space Agen 22 // * under contract to the European Space Agency (ESA) are the *
23 // * intellectual property of ESA. Rights to u 23 // * intellectual property of ESA. Rights to use, copy, modify and *
24 // * redistribute this software for general pu 24 // * redistribute this software for general public use are granted *
25 // * in compliance with any licensing, distrib 25 // * in compliance with any licensing, distribution and development *
26 // * policy adopted by the Geant4 Collaboratio 26 // * policy adopted by the Geant4 Collaboration. This code has been *
27 // * written by QinetiQ Ltd for the European S 27 // * written by QinetiQ Ltd for the European Space Agency, under ESA *
28 // * contract 17191/03/NL/LvH (Aurora Programm 28 // * contract 17191/03/NL/LvH (Aurora Programme). *
29 // * 29 // * *
30 // * By using, copying, modifying or distri 30 // * By using, copying, modifying or distributing the software (or *
31 // * any work based on the software) you ag 31 // * any work based on the software) you agree to acknowledge its *
32 // * use in resulting scientific publicati 32 // * use in resulting scientific publications, and indicate your *
33 // * acceptance of all terms of the Geant4 Sof 33 // * acceptance of all terms of the Geant4 Software license. *
34 // ******************************************* 34 // ********************************************************************
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 63 // 17 August 2011, V.Ivanchenko, provide migration to new design of cross
64 // sections considering this c 64 // sections considering this cross section as element-wise
65 // 65 //
66 // %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 66 // %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
67 ////////////////////////////////////////////// 67 //////////////////////////////////////////////////////////////////////////////
68 // 68 //
69 #include "G4EMDissociationCrossSection.hh" 69 #include "G4EMDissociationCrossSection.hh"
70 #include "G4PhysicalConstants.hh" 70 #include "G4PhysicalConstants.hh"
71 #include "G4SystemOfUnits.hh" 71 #include "G4SystemOfUnits.hh"
72 #include "G4ParticleTable.hh" 72 #include "G4ParticleTable.hh"
73 #include "G4IonTable.hh" 73 #include "G4IonTable.hh"
74 #include "G4HadTmpUtil.hh" 74 #include "G4HadTmpUtil.hh"
75 #include "globals.hh" 75 #include "globals.hh"
76 #include "G4NistManager.hh" 76 #include "G4NistManager.hh"
77 77
78 78
79 G4EMDissociationCrossSection::G4EMDissociation 79 G4EMDissociationCrossSection::G4EMDissociationCrossSection ()
80 : G4VCrossSectionDataSet("Electromagnetic dis 80 : G4VCrossSectionDataSet("Electromagnetic dissociation")
81 { 81 {
82 // This function makes use of the class whic 82 // This function makes use of the class which can sample the virtual photon
83 // spectrum, G4EMDissociationSpectrum. 83 // spectrum, G4EMDissociationSpectrum.
84 84
85 thePhotonSpectrum = new G4EMDissociationSpec 85 thePhotonSpectrum = new G4EMDissociationSpectrum();
86 86
87 // Define other constants. 87 // Define other constants.
88 88
89 r0 = 1.18 * fermi; 89 r0 = 1.18 * fermi;
90 J = 36.8 * MeV; 90 J = 36.8 * MeV;
91 Qprime = 17.0 * MeV; 91 Qprime = 17.0 * MeV;
92 epsilon = 0.0768; 92 epsilon = 0.0768;
93 xd = 0.25; 93 xd = 0.25;
94 } 94 }
95 95
96 ////////////////////////////////////////////// 96 //////////////////////////////////////////////////////////////////////////////
97 97
98 G4EMDissociationCrossSection::~G4EMDissociatio 98 G4EMDissociationCrossSection::~G4EMDissociationCrossSection()
99 { 99 {
100 delete thePhotonSpectrum; 100 delete thePhotonSpectrum;
101 } 101 }
102 ////////////////////////////////////////////// 102 /////////////////////////////////////////////////////////////////////////////
103 // 103 //
104 G4bool 104 G4bool
105 G4EMDissociationCrossSection::IsElementApplica 105 G4EMDissociationCrossSection::IsElementApplicable(const G4DynamicParticle* part,
106 G4int /*ZZ*/, const G4Material*) 106 G4int /*ZZ*/, const G4Material*)
107 { 107 {
108 // 108 //
109 // The condition for the applicability of this 109 // The condition for the applicability of this class is that the projectile
110 // must be an ion and the target must have mor 110 // 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 111 // the value of A for either the projectile or target could be much higher,
112 // since for cases where both he projectile an 112 // since for cases where both he projectile and target are medium to small
113 // Z, the probability of the EMD process is, I 113 // Z, the probability of the EMD process is, I think, VERY small.
114 // 114 //
115 if (G4ParticleTable::GetParticleTable()->Get 115 if (G4ParticleTable::GetParticleTable()->GetIonTable()->IsIon(part->GetDefinition())) {
116 return true; 116 return true;
117 } else { 117 } else {
118 return false; 118 return false;
119 } 119 }
120 } 120 }
121 121
122 ////////////////////////////////////////////// 122 //////////////////////////////////////////////////////////////////////////////
123 // 123 //
124 G4double G4EMDissociationCrossSection::GetElem 124 G4double G4EMDissociationCrossSection::GetElementCrossSection
125 (const G4DynamicParticle* theDynamicParticle 125 (const G4DynamicParticle* theDynamicParticle, G4int Z,
126 const G4Material*) 126 const G4Material*)
127 { 127 {
128 // VI protection for Hydrogen 128 // VI protection for Hydrogen
129 if(1 >= Z) { return 0.0; } 129 if(1 >= Z) { return 0.0; }
130 << 130
131 // Zero cross-section for particles with kin <<
132 // possible abort signal from bad arithmetic <<
133 if ( theDynamicParticle->GetKineticEnergy() <<
134 <<
135 // 131 //
136 // Get relevant information about the projec 132 // Get relevant information about the projectile and target (A, Z) and
137 // velocity of the projectile. 133 // velocity of the projectile.
138 // 134 //
139 const G4ParticleDefinition *definitionP = th 135 const G4ParticleDefinition *definitionP = theDynamicParticle->GetDefinition();
140 G4double AP = definitionP->GetBaryonNumber 136 G4double AP = definitionP->GetBaryonNumber();
141 G4double ZP = definitionP->GetPDGCharge(); 137 G4double ZP = definitionP->GetPDGCharge();
142 G4double b = theDynamicParticle->GetBeta( << 138 G4double b = theDynamicParticle->Get4Momentum().beta();
143 if (b <= 0.0 && b >= 1.0) { return 0.0; } <<
144 139
145 G4double AT = G4NistManager::Instance()->G 140 G4double AT = G4NistManager::Instance()->GetAtomicMassAmu(Z);
146 G4double ZT = (G4double)Z; 141 G4double ZT = (G4double)Z;
147 G4double bmin = thePhotonSpectrum->GetCloses 142 G4double bmin = thePhotonSpectrum->GetClosestApproach(AP, ZP, AT, ZT, b);
148 // 143 //
149 // 144 //
150 // Calculate the cross-section for the proje 145 // Calculate the cross-section for the projectile and then the target. The
151 // information is returned in a G4PhysicsFre 146 // information is returned in a G4PhysicsFreeVector, which separates out the
152 // cross-sections for the E1 and E2 moments 147 // cross-sections for the E1 and E2 moments of the virtual photon field, and
153 // the energies (GDR and GQR). 148 // the energies (GDR and GQR).
154 // 149 //
155 G4PhysicsFreeVector *theProjectileCrossSecti 150 G4PhysicsFreeVector *theProjectileCrossSections =
156 GetCrossSectionForProjectile (AP, ZP, AT, 151 GetCrossSectionForProjectile (AP, ZP, AT, ZT, b, bmin);
157 G4double crossSection = 152 G4double crossSection =
158 (*theProjectileCrossSections)[0]+(*theProj 153 (*theProjectileCrossSections)[0]+(*theProjectileCrossSections)[1];
159 delete theProjectileCrossSections; 154 delete theProjectileCrossSections;
160 G4PhysicsFreeVector *theTargetCrossSections 155 G4PhysicsFreeVector *theTargetCrossSections =
161 GetCrossSectionForTarget (AP, ZP, AT, ZT, 156 GetCrossSectionForTarget (AP, ZP, AT, ZT, b, bmin);
162 crossSection += 157 crossSection +=
163 (*theTargetCrossSections)[0]+(*theTargetCr 158 (*theTargetCrossSections)[0]+(*theTargetCrossSections)[1];
164 delete theTargetCrossSections; 159 delete theTargetCrossSections;
165 return crossSection; 160 return crossSection;
166 } 161 }
167 ////////////////////////////////////////////// 162 ////////////////////////////////////////////////////////////////////////////////
168 // 163 //
169 G4PhysicsFreeVector * 164 G4PhysicsFreeVector *
170 G4EMDissociationCrossSection::GetCrossSectionF 165 G4EMDissociationCrossSection::GetCrossSectionForProjectile (G4double AP,
171 G4double ZP, G4double /* AT */, G4double ZT, 166 G4double ZP, G4double /* AT */, G4double ZT, G4double b, G4double bmin)
172 { 167 {
173 // 168 //
174 // 169 //
175 // Use Wilson et al's approach to calculate th 170 // 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 171 // and E2 moments of the field at the giant dipole and quadrupole resonances
177 // respectively, Note that the algorithm is t 172 // respectively, Note that the algorithm is traditionally applied to the
178 // EMD break-up of the projectile in the field 173 // EMD break-up of the projectile in the field of the target, as is implemented
179 // here. 174 // here.
180 // 175 //
181 // Initialise variables and calculate the ener 176 // Initialise variables and calculate the energies for the GDR and GQR.
182 // 177 //
183 G4double AProot3 = G4Pow::GetInstance()->A13 << 178 G4double AProot3 = G4Pow::GetInstance()->powA(AP,1.0/3.0);
184 G4double u = 3.0 * J / Qprime / AProot 179 G4double u = 3.0 * J / Qprime / AProot3;
185 G4double R0 = r0 * AProot3; 180 G4double R0 = r0 * AProot3;
186 G4double E_GDR = hbarc / std::sqrt(0.7*amu_ 181 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 + 182 (1.0 + u - (1.0 + epsilon + 3.0*u)/(1.0 + epsilon + u)*epsilon));
188 G4double E_GQR = 63.0 * MeV / AProot3; 183 G4double E_GQR = 63.0 * MeV / AProot3;
189 // 184 //
190 // 185 //
191 // Determine the virtual photon spectra at the 186 // Determine the virtual photon spectra at these energies.
192 // 187 //
193 G4double ZTsq = ZT * ZT; 188 G4double ZTsq = ZT * ZT;
194 G4double nE1 = ZTsq * 189 G4double nE1 = ZTsq *
195 thePhotonSpectrum->GetGeneralE1Spectrum(E_ 190 thePhotonSpectrum->GetGeneralE1Spectrum(E_GDR, b, bmin);
196 G4double nE2 = ZTsq * 191 G4double nE2 = ZTsq *
197 thePhotonSpectrum->GetGeneralE2Spectrum(E_ 192 thePhotonSpectrum->GetGeneralE2Spectrum(E_GQR, b, bmin);
198 // 193 //
199 // 194 //
200 // Now calculate the cross-section of the proj 195 // Now calculate the cross-section of the projectile for interaction with the
201 // E1 and E2 fields. 196 // E1 and E2 fields.
202 // 197 //
203 G4double sE1 = 60.0 * millibarn * MeV * (AP- 198 G4double sE1 = 60.0 * millibarn * MeV * (AP-ZP)*ZP/AP;
204 G4double sE2 = 0.22 * microbarn / MeV * ZP * 199 G4double sE2 = 0.22 * microbarn / MeV * ZP * AProot3 * AProot3;
205 if (AP > 100.0) sE2 *= 0.9; 200 if (AP > 100.0) sE2 *= 0.9;
206 else if (AP > 40.0) sE2 *= 0.6; 201 else if (AP > 40.0) sE2 *= 0.6;
207 else sE2 *= 0.3; 202 else sE2 *= 0.3;
208 // 203 //
209 // 204 //
210 // ... and multiply with the intensity of the 205 // ... and multiply with the intensity of the virtual photon spectra to get
211 // the probability of interaction. 206 // the probability of interaction.
212 // 207 //
213 G4PhysicsFreeVector *theCrossSectionVector = 208 G4PhysicsFreeVector *theCrossSectionVector = new G4PhysicsFreeVector(2);
214 theCrossSectionVector->PutValue(0, E_GDR, sE 209 theCrossSectionVector->PutValue(0, E_GDR, sE1*nE1);
215 theCrossSectionVector->PutValue(1, E_GQR, sE 210 theCrossSectionVector->PutValue(1, E_GQR, sE2*nE2*E_GQR*E_GQR);
216 211
217 return theCrossSectionVector; 212 return theCrossSectionVector;
218 } 213 }
219 214
220 ////////////////////////////////////////////// 215 ////////////////////////////////////////////////////////////////////////////////
221 // 216 //
222 G4PhysicsFreeVector * 217 G4PhysicsFreeVector *
223 G4EMDissociationCrossSection::GetCrossSectionF 218 G4EMDissociationCrossSection::GetCrossSectionForTarget (G4double AP,
224 G4double ZP, G4double AT, G4double ZT, G4dou 219 G4double ZP, G4double AT, G4double ZT, G4double b, G4double bmin)
225 { 220 {
226 // 221 //
227 // This is a cheaky little member function to 222 // This is a cheaky little member function to calculate the probability of
228 // EMD for the target in the field of the proj 223 // EMD for the target in the field of the projectile ... just by reversing the
229 // A and Z's for the participants. 224 // A and Z's for the participants.
230 // 225 //
231 return GetCrossSectionForProjectile (AT, ZT, 226 return GetCrossSectionForProjectile (AT, ZT, AP, ZP, b, bmin);
232 } 227 }
233 228
234 ////////////////////////////////////////////// 229 ////////////////////////////////////////////////////////////////////////////////
235 // 230 //
236 G4double 231 G4double
237 G4EMDissociationCrossSection::GetWilsonProbabi 232 G4EMDissociationCrossSection::GetWilsonProbabilityForProtonDissociation(G4double A,
238 233 G4double Z)
239 { 234 {
240 // 235 //
241 // This is a simple algorithm to choose whethe 236 // This is a simple algorithm to choose whether a proton or neutron is ejected
242 // from the nucleus in the EMD interaction. 237 // from the nucleus in the EMD interaction.
243 // 238 //
244 G4double p = 0.0; 239 G4double p = 0.0;
245 if (Z < 2.0) << 240 if (Z < 6.0)
246 p = 0.0; // To avoid to remove one proton <<
247 else if (Z < 6.0) <<
248 p = 0.5; 241 p = 0.5;
249 else if (Z < 8.0) 242 else if (Z < 8.0)
250 p = 0.6; 243 p = 0.6;
251 else if (Z < 14.0) 244 else if (Z < 14.0)
252 p = 0.7; 245 p = 0.7;
253 else 246 else
254 { 247 {
255 G4double p1 = (G4double) Z / (G4double) A; 248 G4double p1 = (G4double) Z / (G4double) A;
256 G4double p2 = 1.95*G4Exp(-0.075*Z); 249 G4double p2 = 1.95*G4Exp(-0.075*Z);
257 if (p1 < p2) p = p1; 250 if (p1 < p2) p = p1;
258 else p = p2; 251 else p = p2;
259 } 252 }
260 253
261 return p; 254 return p;
262 } 255 }
263 256