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25 //
26 // INCL++ intra-nuclear cascade model
27 // Alain Boudard, CEA-Saclay, France
28 // Joseph Cugnon, University of Liege, Belgium
29 // Jean-Christophe David, CEA-Saclay, France
30 // Pekka Kaitaniemi, CEA-Saclay, France, and Helsinki Institute of Physics, Finland
31 // Sylvie Leray, CEA-Saclay, France
32 // Davide Mancusi, CEA-Saclay, France
33 //
34 #define INCLXX_IN_GEANT4_MODE 1
35
36 #include "globals.hh"
37
38 /** \file G4INCLParticleSampler.cc
39 * \brief Class for sampling particles in a nucleus
40 *
41 * \date 18 July 2012
42 * \author Davide Mancusi
43 */
44
45 #include "G4INCLParticleSampler.hh"
46 #include "G4INCLParticleTable.hh"
47 #include "G4INCLNuclearDensityFactory.hh"
48
49 namespace G4INCL {
50
51 ParticleSampler::ParticleSampler(const G4int A, const G4int Z, const G4int S) :
52 sampleOneProton(&ParticleSampler::sampleOneParticleWithoutRPCorrelation),
53 sampleOneNeutron(&ParticleSampler::sampleOneParticleWithoutRPCorrelation),
54 theA(A),
55 theZ(Z),
56 theS(S),
57 theDensity(NULL),
58 thePotential(NULL)
59 {
60 std::fill(theRCDFTable, theRCDFTable + UnknownParticle, static_cast<InterpolationTable *>(NULL));
61 std::fill(thePCDFTable, thePCDFTable + UnknownParticle, static_cast<InterpolationTable *>(NULL));
62 std::fill(rpCorrelationCoefficient, rpCorrelationCoefficient + UnknownParticle, 1.);
63 rpCorrelationCoefficient[Proton] = ParticleTable::getRPCorrelationCoefficient(Proton);
64 rpCorrelationCoefficient[Neutron] = ParticleTable::getRPCorrelationCoefficient(Neutron);
65 rpCorrelationCoefficient[Lambda] = ParticleTable::getRPCorrelationCoefficient(Lambda);
66 }
67
68 ParticleSampler::~ParticleSampler() {
69 }
70
71 void ParticleSampler::setDensity(NuclearDensity const * const d) {
72 theDensity = d;
73 updateSampleOneParticleMethods();
74 }
75
76 void ParticleSampler::setPotential(NuclearPotential::INuclearPotential const * const p) {
77 thePotential = p;
78 updateSampleOneParticleMethods();
79 }
80
81 void ParticleSampler::updateSampleOneParticleMethods() {
82 if(theDensity && thePotential) {
83 if(rpCorrelationCoefficient[Proton]>0.99999) {
84 sampleOneProton = &ParticleSampler::sampleOneParticleWithRPCorrelation;
85 } else {
86 sampleOneProton = &ParticleSampler::sampleOneParticleWithFuzzyRPCorrelation;
87 }
88 if(rpCorrelationCoefficient[Neutron]>0.99999) {
89 sampleOneNeutron = &ParticleSampler::sampleOneParticleWithRPCorrelation;
90 } else {
91 sampleOneNeutron = &ParticleSampler::sampleOneParticleWithFuzzyRPCorrelation;
92 }
93 } else {
94 sampleOneProton = &ParticleSampler::sampleOneParticleWithoutRPCorrelation;
95 sampleOneNeutron = &ParticleSampler::sampleOneParticleWithoutRPCorrelation;
96 }
97 }
98
99 ParticleList ParticleSampler::sampleParticles(const ThreeVector &position) {
100 ParticleList aList;
101 sampleParticlesIntoList(position, aList);
102 return aList;
103 }
104
105 void ParticleSampler::sampleParticlesIntoList(const ThreeVector &position, ParticleList &theList) {
106
107 if(sampleOneProton == &ParticleSampler::sampleOneParticleWithoutRPCorrelation) {
108 // sampling without correlation, we need to initialize the CDF tables
109 theRCDFTable[Proton] = NuclearDensityFactory::createRCDFTable(Proton, theA, theZ);
110 thePCDFTable[Proton] = NuclearDensityFactory::createPCDFTable(Proton, theA, theZ);
111 theRCDFTable[Neutron] = NuclearDensityFactory::createRCDFTable(Neutron, theA, theZ);
112 thePCDFTable[Neutron] = NuclearDensityFactory::createPCDFTable(Neutron, theA, theZ);
113 theRCDFTable[Lambda] = NuclearDensityFactory::createRCDFTable(Lambda, theA, theZ);
114 thePCDFTable[Lambda] = NuclearDensityFactory::createPCDFTable(Lambda, theA, theZ);
115 }
116
117 theList.resize(theA);
118 if(theA > 2) {
119 ParticleType type = Proton;
120 ParticleSamplerMethod sampleOneParticle = sampleOneProton;
121 for(G4int i = 0; i < theA; ++i) {
122 if(i == theZ) { // Nucleons [Z..A-1] are neutrons
123 type = Lambda;
124 sampleOneParticle = sampleOneNeutron; // hypothesis: Lambdas follow the same rules than neutrons
125 }
126 if(i == theZ - theS) type = Neutron;
127 Particle *p = (this->*sampleOneParticle)(type);
128 p->setPosition(position + p->getPosition());
129 theList[i] = p;
130 }
131 } else {
132 // For deuterons, only sample the proton position and momentum. The
133 // neutron position and momenta are determined by the conditions of
134 // vanishing CM position and total momentum.
135 // assert(theZ==1);
136 Particle *aProton = (this->*(this->sampleOneProton))(Proton);
137 Particle *aNeutron = new Particle(Neutron, -aProton->getMomentum(), position - aProton->getPosition());
138 aProton->setPosition(position + aProton->getPosition());
139 theList[0] = aProton;
140 theList[1] = aNeutron;
141 }
142 }
143
144 Particle *ParticleSampler::sampleOneParticleWithRPCorrelation(const ParticleType t) const {
145 // assert(theDensity && thePotential);
146 const G4double theFermiMomentum = thePotential->getFermiMomentum(t);
147 const ThreeVector momentumVector = Random::sphereVector(theFermiMomentum);
148 const G4double momentumAbs = momentumVector.mag();
149 const G4double momentumRatio = momentumAbs/theFermiMomentum;
150 const G4double reflectionRadius = theDensity->getMaxRFromP(t, momentumRatio);
151 const ThreeVector positionVector = Random::sphereVector(reflectionRadius);
152 Particle *aParticle = new Particle(t, momentumVector, positionVector);
153 aParticle->setUncorrelatedMomentum(momentumAbs);
154 return aParticle;
155 }
156
157 Particle *ParticleSampler::sampleOneParticleWithoutRPCorrelation(const ParticleType t) const {
158 const G4double position = (*(theRCDFTable[t]))(Random::shoot());
159 const G4double momentum = (*(thePCDFTable[t]))(Random::shoot());
160 ThreeVector positionVector = Random::normVector(position);
161 ThreeVector momentumVector = Random::normVector(momentum);
162 return new Particle(t, momentumVector, positionVector);
163 }
164
165 Particle *ParticleSampler::sampleOneParticleWithFuzzyRPCorrelation(const ParticleType t) const {
166 // assert(theDensity && thePotential);
167 std::pair<G4double,G4double> ranNumbers = Random::correlatedUniform(rpCorrelationCoefficient[t]);
168 const G4double x = Math::pow13(ranNumbers.first);
169 const G4double y = Math::pow13(ranNumbers.second);
170 const G4double theFermiMomentum = thePotential->getFermiMomentum(t);
171 const ThreeVector momentumVector = Random::normVector(y*theFermiMomentum);
172 const G4double reflectionRadius = theDensity->getMaxRFromP(t, x);
173 const ThreeVector positionVector = Random::sphereVector(reflectionRadius);
174 Particle *aParticle = new Particle(t, momentumVector, positionVector);
175 aParticle->setUncorrelatedMomentum(x*theFermiMomentum);
176 return aParticle;
177 }
178
179 }
180
181