source: trunk/source/processes/hadronic/models/binary_cascade/src/G4RKFieldIntegrator.cc@ 1337

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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 *
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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 *
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23// * acceptance of all terms of the Geant4 Software license. *
24// ********************************************************************
25//
26// G4RKFieldIntegrator
27#include "G4RKFieldIntegrator.hh"
28#include "G4NucleiProperties.hh"
29#include "G4FermiMomentum.hh"
30#include "G4NuclearFermiDensity.hh"
31#include "G4NuclearShellModelDensity.hh"
32#include "G4Nucleon.hh"
33
34// Class G4RKFieldIntegrator
35//*************************************************************************************************************************************
36
37// only theActive are propagated, nothing else
38// only theSpectators define the field, nothing else
39
40void G4RKFieldIntegrator::Transport(G4KineticTrackVector &theActive, const G4KineticTrackVector &theSpectators, G4double theTimeStep)
41{
42 (void)theActive;
43 (void)theSpectators;
44 (void)theTimeStep;
45}
46
47
48G4double G4RKFieldIntegrator::CalculateTotalEnergy(const G4KineticTrackVector& Barions)
49{
50 const G4double Alpha = 0.25/fermi/fermi;
51 const G4double t1 = -7264.04*fermi*fermi*fermi;
52 const G4double tGamma = 87.65*fermi*fermi*fermi*fermi*fermi*fermi;
53// const G4double Gamma = 1.676;
54 const G4double Vo = -0.498*fermi;
55 const G4double GammaY = 1.4*fermi;
56
57 G4double Etot = 0;
58 G4int nBarion = Barions.size();
59 for(G4int c1 = 0; c1 < nBarion; c1++)
60 {
61 G4KineticTrack* p1 = Barions.operator[](c1);
62 // Ekin
63 Etot += p1->Get4Momentum().e();
64 for(G4int c2 = c1 + 1; c2 < nBarion; c2++)
65 {
66 G4KineticTrack* p2 = Barions.operator[](c2);
67 G4ThreeVector rv = p1->GetPosition() - p2->GetPosition();
68 G4double r12 = std::sqrt(rv*rv)*fermi;
69
70 // Esk2
71 Etot += t1*std::pow(Alpha/pi, 3/2)*std::exp(-Alpha*r12*r12);
72
73 // Eyuk
74 Etot += Vo*0.5/r12*std::exp(1/(4*Alpha*GammaY*GammaY))*
75 (std::exp(-r12/GammaY)*(1 - Erf(0.5/GammaY/std::sqrt(Alpha) - std::sqrt(Alpha)*r12)) -
76 std::exp( r12/GammaY)*(1 - Erf(0.5/GammaY/std::sqrt(Alpha) + std::sqrt(Alpha)*r12)));
77
78 // Ecoul
79 Etot += 1.44*p1->GetDefinition()->GetPDGCharge()*p2->GetDefinition()->GetPDGCharge()/r12*Erf(std::sqrt(Alpha)*r12);
80
81 // Epaul
82 Etot = 0;
83
84 for(G4int c3 = c2 + 1; c3 < nBarion; c3++)
85 {
86 G4KineticTrack* p3 = Barions.operator[](c3);
87 G4ThreeVector rv = p1->GetPosition() - p3->GetPosition();
88 G4double r13 = std::sqrt(rv*rv)*fermi;
89
90 // Esk3
91 Etot = tGamma*std::pow(4*Alpha*Alpha/3/pi/pi, 1.5)*std::exp(-Alpha*(r12*r12 + r13*r13));
92 }
93 }
94 }
95 return Etot;
96}
97
98//************************************************************************************************
99// originated from the Numerical recipes error function
100G4double G4RKFieldIntegrator::Erf(G4double X)
101{
102 const G4double Z1 = 1;
103 const G4double HF = Z1/2;
104 const G4double C1 = 0.56418958;
105
106 const G4double P10 = +3.6767877;
107 const G4double Q10 = +3.2584593;
108 const G4double P11 = -9.7970465E-2;
109
110 static G4double P2[5] = { 7.3738883, 6.8650185, 3.0317993, 0.56316962, 4.3187787e-5 };
111 static G4double Q2[5] = { 7.3739609, 15.184908, 12.79553, 5.3542168, 1. };
112
113 const G4double P30 = -1.2436854E-1;
114 const G4double Q30 = +4.4091706E-1;
115 const G4double P31 = -9.6821036E-2;
116
117 G4double V = std::abs(X);
118 G4double H;
119 G4double Y;
120 G4int c1;
121
122 if(V < HF)
123 {
124 Y = V*V;
125 H = X*(P10 + P11*Y)/(Q10+Y);
126 }
127 else
128 {
129 if(V < 4)
130 {
131 G4double AP = P2[4];
132 G4double AQ = Q2[4];
133 for(c1 = 3; c1 >= 0; c1--)
134 {
135 AP = P2[c1] + V*AP;
136 AQ = Q2[c1] + V*AQ;
137 }
138 H = 1 - std::exp(-V*V)*AP/AQ;
139 }
140 else
141 {
142 Y = 1./V*V;
143 H = 1 - std::exp(-V*V)*(C1+Y*(P30 + P31*Y)/(Q30 + Y))/V;
144 }
145 if (X < 0)
146 H =- H;
147 }
148 return H;
149}
150
151//************************************************************************************************
152//This is a QMD version to calculate excitation energy of a fragment,
153//which consists from G4KTV &the Particles
154/*
155G4double G4RKFieldIntegrator::GetExcitationEnergy(const G4KineticTrackVector &theParticles)
156{
157 // Excitation energy of a fragment consisting from A nucleons and Z protons
158 // is Etot - Z*Mp - (A - Z)*Mn - B(A, Z), where B(A,Z) is the binding energy of fragment
159 // and Mp, Mn are proton and neutron mass, respectively.
160 G4int NZ = 0;
161 G4int NA = 0;
162 G4double Etot = CalculateTotalEnergy(theParticles);
163 for(G4int cParticle = 0; cParticle < theParticles.length(); cParticle++)
164 {
165 G4KineticTrack* pKineticTrack = theParticles.at(cParticle);
166 G4int Encoding = std::abs(pKineticTrack->GetDefinition()->GetPDGEncoding());
167 if (Encoding == 2212)
168 NZ++, NA++;
169 if (Encoding == 2112)
170 NA++;
171 Etot -= pKineticTrack->GetDefinition()->GetPDGMass();
172 }
173 return Etot - G4NucleiProperties::GetBindingEnergy(NZ, NA);
174}
175*/
176
177//*************************************************************************************************************************************
178//This is a simplified method to get excitation energy of a residual
179// nucleus with nHitNucleons.
180G4double G4RKFieldIntegrator::GetExcitationEnergy(G4int nHitNucleons, const G4KineticTrackVector &)
181{
182 const G4double MeanE = 50;
183 G4double Sum = 0;
184 for(G4int c1 = 0; c1 < nHitNucleons; c1++)
185 {
186 Sum += -MeanE*std::log(G4UniformRand());
187 }
188 return Sum;
189}
190//*************************************************************************************************************************************
191
192/*
193//This is free propagation of particles for CASCADE mode. Target nucleons should be frozen
194void G4RKFieldIntegrator::Integrate(G4KineticTrackVector& theParticles)
195 {
196 for(G4int cParticle = 0; cParticle < theParticles.length(); cParticle++)
197 {
198 G4KineticTrack* pKineticTrack = theParticles.at(cParticle);
199 pKineticTrack->SetPosition(pKineticTrack->GetPosition() + theTimeStep*pKineticTrack->Get4Momentum().boostVector());
200 }
201 }
202*/
203//*************************************************************************************************************************************
204
205void G4RKFieldIntegrator::Integrate(const G4KineticTrackVector& theBarions, G4double theTimeStep)
206{
207 for(size_t cParticle = 0; cParticle < theBarions.size(); cParticle++)
208 {
209 G4KineticTrack* pKineticTrack = theBarions[cParticle];
210 pKineticTrack->SetPosition(pKineticTrack->GetPosition() + theTimeStep*pKineticTrack->Get4Momentum().boostVector());
211 }
212}
213
214//*************************************************************************************************************************************
215
216// constant to calculate theCoulomb barrier
217const G4double G4RKFieldIntegrator::coulomb = 1.44 / 1.14 * MeV;
218
219// kaon's potential constant (real part only)
220// 0.35 + i0.82 or 0.63 + i0.89 fermi
221const G4double G4RKFieldIntegrator::a_kaon = 0.35;
222
223// pion's potential constant (real part only)
224//!! for pions it has todiffer from kaons
225// 0.35 + i0.82 or 0.63 + i0.89 fermi
226const G4double G4RKFieldIntegrator::a_pion = 0.35;
227
228// antiproton's potential constant (real part only)
229// 1.53 + i2.50 fermi
230const G4double G4RKFieldIntegrator::a_antiproton = 1.53;
231
232// methods for calculating potentials for different types of particles
233// aPosition is relative to the nucleus center
234G4double G4RKFieldIntegrator::GetNeutronPotential(G4double )
235{
236 /*
237 const G4double Mn = 939.56563 * MeV; // mass of nuetron
238
239 G4VNuclearDensity *theDencity;
240 if(theA < 17) theDencity = new G4NuclearShellModelDensity(theA, theZ);
241 else theDencity = new G4NuclearFermiDensity(theA, theZ);
242
243 // GetDencity() accepts only G4ThreeVector so build it:
244 G4ThreeVector aPosition(0.0, 0.0, radius);
245 G4double density = theDencity->GetDensity(aPosition);
246 delete theDencity;
247
248 G4FermiMomentum *fm = new G4FermiMomentum();
249 fm->Init(theA, theZ);
250 G4double fermiMomentum = fm->GetFermiMomentum(density);
251 delete fm;
252
253 return sqr(fermiMomentum)/(2 * Mn)
254 + G4CreateNucleus::GetBindingEnergy(theZ, theA)/theA;
255 //+ G4NucleiProperties::GetBindingEnergy(theZ, theA)/theA;
256 */
257
258 return 0.0;
259}
260
261G4double G4RKFieldIntegrator::GetProtonPotential(G4double )
262{
263 /*
264 // calculate Coulomb barrier value
265 G4double theCoulombBarrier = coulomb * theZ/(1. + std::pow(theA, 1./3.));
266 const G4double Mp = 938.27231 * MeV; // mass of proton
267
268 G4VNuclearDensity *theDencity;
269 if(theA < 17) theDencity = new G4NuclearShellModelDensity(theA, theZ);
270 else theDencity = new G4NuclearFermiDensity(theA, theZ);
271
272 // GetDencity() accepts only G4ThreeVector so build it:
273 G4ThreeVector aPosition(0.0, 0.0, radius);
274 G4double density = theDencity->GetDensity(aPosition);
275 delete theDencity;
276
277 G4FermiMomentum *fm = new G4FermiMomentum();
278 fm->Init(theA, theZ);
279 G4double fermiMomentum = fm->GetFermiMomentum(density);
280 delete fm;
281
282 return sqr(fermiMomentum)/ (2 * Mp)
283 + G4CreateNucleus::GetBindingEnergy(theZ, theA)/theA;
284 //+ G4NucleiProperties::GetBindingEnergy(theZ, theA)/theA
285 + theCoulombBarrier;
286 */
287
288 return 0.0;
289}
290
291G4double G4RKFieldIntegrator::GetAntiprotonPotential(G4double )
292{
293 /*
294 //G4double theM = G4NucleiProperties::GetAtomicMass(theA, theZ);
295 G4double theM = theZ * G4Proton::Proton()->GetPDGMass()
296 + (theA - theZ) * G4Neutron::Neutron()->GetPDGMass()
297 + G4CreateNucleus::GetBindingEnergy(theZ, theA);
298
299 const G4double Mp = 938.27231 * MeV; // mass of proton
300 G4double mu = (theM * Mp)/(theM + Mp);
301
302 // antiproton's potential coefficient
303 // V = coeff_antiproton * nucleus_density
304 G4double coeff_antiproton = -2.*pi/mu * (1. + Mp) * a_antiproton;
305
306 G4VNuclearDensity *theDencity;
307 if(theA < 17) theDencity = new G4NuclearShellModelDensity(theA, theZ);
308 else theDencity = new G4NuclearFermiDensity(theA, theZ);
309
310 // GetDencity() accepts only G4ThreeVector so build it:
311 G4ThreeVector aPosition(0.0, 0.0, radius);
312 G4double density = theDencity->GetDensity(aPosition);
313 delete theDencity;
314
315 return coeff_antiproton * density;
316 */
317
318 return 0.0;
319}
320
321G4double G4RKFieldIntegrator::GetKaonPotential(G4double )
322{
323 /*
324 //G4double theM = G4NucleiProperties::GetAtomicMass(theA, theZ);
325 G4double theM = theZ * G4Proton::Proton()->GetPDGMass()
326 + (theA - theZ) * G4Neutron::Neutron()->GetPDGMass()
327 + G4CreateNucleus::GetBindingEnergy(theZ, theA);
328
329 const G4double Mk = 496. * MeV; // mass of "kaon"
330 G4double mu = (theM * Mk)/(theM + Mk);
331
332 // kaon's potential coefficient
333 // V = coeff_kaon * nucleus_density
334 G4double coeff_kaon = -2.*pi/mu * (1. + Mk/theM) * a_kaon;
335
336 G4VNuclearDensity *theDencity;
337 if(theA < 17) theDencity = new G4NuclearShellModelDensity(theA, theZ);
338 else theDencity = new G4NuclearFermiDensity(theA, theZ);
339
340 // GetDencity() accepts only G4ThreeVector so build it:
341 G4ThreeVector aPosition(0.0, 0.0, radius);
342 G4double density = theDencity->GetDensity(aPosition);
343 delete theDencity;
344
345 return coeff_kaon * density;
346 */
347
348 return 0.0;
349}
350
351G4double G4RKFieldIntegrator::GetPionPotential(G4double )
352{
353 /*
354 //G4double theM = G4NucleiProperties::GetAtomicMass(theA, theZ);
355 G4double theM = theZ * G4Proton::Proton()->GetPDGMass()
356 + (theA - theZ) * G4Neutron::Neutron()->GetPDGMass()
357 + G4CreateNucleus::GetBindingEnergy(theZ, theA);
358
359 const G4double Mpi = 139. * MeV; // mass of "pion"
360 G4double mu = (theM * Mpi)/(theM + Mpi);
361
362 // pion's potential coefficient
363 // V = coeff_pion * nucleus_density
364 G4double coeff_pion = -2.*pi/mu * (1. + Mpi) * a_pion;
365
366 G4VNuclearDensity *theDencity;
367 if(theA < 17) theDencity = new G4NuclearShellModelDensity(theA, theZ);
368 else theDencity = new G4NuclearFermiDensity(theA, theZ);
369
370 // GetDencity() accepts only G4ThreeVector so build it:
371 G4ThreeVector aPosition(0.0, 0.0, radius);
372 G4double density = theDencity->GetDensity(aPosition);
373 delete theDencity;
374
375 return coeff_pion * density;
376 */
377
378 return 0.0;
379}
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