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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 H
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 #include "G4INCLElasticChannel.hh"
39 #include "G4INCLRandom.hh"
40 #include "G4INCLKinematicsUtils.hh"
41 #include "G4INCLParticleTable.hh"
42 #include "G4INCLCrossSections.hh"
43 #include "G4INCLGlobals.hh"
44
45 namespace G4INCL {
46
47 ElasticChannel::ElasticChannel(Particle *p1,
48 :particle1(p1), particle2(p2)
49 {
50 }
51
52 ElasticChannel::~ElasticChannel()
53 {
54 }
55
56 void ElasticChannel::fillFinalState(FinalSta
57 {
58 ParticleType p1TypeOld = particle1->getTyp
59 ParticleType p2TypeOld = particle2->getTyp
60
61 /* Concerning the way we calculate the lab
62 * in CrossSections::elasticNNLegacy().
63 */
64 const G4double s = KinematicsUtils::square
65 const G4double pl = KinematicsUtils::momen
66
67 const G4int isospin = ParticleTable::getIs
68 ParticleTable::getIsospin(particle2->get
69
70 // Calculate the outcome of the channel:
71 G4double psq = particle1->getMomentum().ma
72 G4double pnorm = std::sqrt(psq);
73 G4double b = CrossSections::calculateNNAng
74 G4double btmax = 4.0 * psq * b;
75 G4double z = std::exp(-btmax);
76 G4double ranres = Random::shoot();
77 G4double y = 1.0 - ranres * (1.0 - z);
78 G4double T = std::log(y)/b;
79 G4int iexpi = 0;
80 G4double apt = 1.0;
81
82 // Handle np case
83 if((particle1->getType() == Proton && part
84 (particle1->getType() == Neutron && par
85 if(pl > 800.0) {
86 const G4double x = 0.001 * pl; // Tran
87 apt = (800.0/pl)*(800.0/pl);
88 G4double cpt = std::max(6.23 * std::ex
89 G4double alphac = 100.0 * 1.0e-6;
90 G4double aaa = (1 + apt) * (1 - std::e
91 G4double argu = psq * alphac;
92
93 if(argu >= 8) {
94 argu = 0.0;
95 } else {
96 argu = std::exp(-4.0 * argu);
97 }
98
99 G4double aac = cpt * (1.0 - argu)/alph
100 G4double fracpn = aaa/(aac + aaa);
101 if(Random::shoot() > fracpn) {
102 z = std::exp(-4.0 * psq *alphac);
103 iexpi = 1;
104 y = 1.0 - ranres*(1.0 - z);
105 T = std::log(y)/alphac;
106 }
107 }
108 }
109
110 G4double ctet = 1.0 + 0.5*T/psq;
111 if(std::abs(ctet) > 1.0) ctet = Math::sign
112 G4double stet = std::sqrt(1.0 - ctet*ctet)
113 G4double rndm = Random::shoot();
114
115 G4double fi = Math::twoPi * rndm;
116 G4double cfi = std::cos(fi);
117 G4double sfi = std::sin(fi);
118
119 G4double xx = particle1->getMomentum().per
120 G4double zz = std::pow(particle1->getMomen
121
122 if(xx >= (zz * 1.0e-8)) {
123 ThreeVector p = particle1->getMomentum()
124 G4double yn = std::sqrt(xx);
125 G4double zn = yn * pnorm;
126 G4double ex[3], ey[3], ez[3];
127 ez[0] = p.getX() / pnorm;
128 ez[1] = p.getY() / pnorm;
129 ez[2] = p.getZ() / pnorm;
130
131 // Vector Ex is chosen arbitrarily:
132 ex[0] = p.getY() / yn;
133 ex[1] = -p.getX() / yn;
134 ex[2] = 0.0;
135
136 ey[0] = p.getX() * p.getZ() / zn;
137 ey[1] = p.getY() * p.getZ() / zn;
138 ey[2] = -xx/zn;
139
140 G4double pX = (ex[0]*cfi*stet + ey[0]*sf
141 G4double pY = (ex[1]*cfi*stet + ey[1]*sf
142 G4double pZ = (ex[2]*cfi*stet + ey[2]*sf
143
144 ThreeVector p1momentum = ThreeVector(pX,
145 particle1->setMomentum(p1momentum);
146 particle2->setMomentum(-p1momentum);
147 } else { // if(xx < (zz * 1.0e-8)) {
148 G4double momZ = particle1->getMomentum()
149 G4double pX = momZ * cfi * stet;
150 G4double pY = momZ * sfi * stet;
151 G4double pZ = momZ * ctet;
152
153 ThreeVector p1momentum(pX, pY, pZ);
154 particle1->setMomentum(p1momentum);
155 particle2->setMomentum(-p1momentum);
156 }
157
158 // Handle backward scattering here.
159
160 if((particle1->getType() == Proton && part
161 (particle1->getType() == Neutron && par
162 rndm = Random::shoot();
163 apt = 1.0;
164 if(pl > 800.0) {
165 apt = std::pow(800.0/pl, 2);
166 }
167 if(iexpi == 1 || rndm > 1.0/(1.0 + apt))
168 particle1->setType(p2TypeOld);
169 particle2->setType(p1TypeOld);
170 }
171 }
172
173 // Note: there is no need to update the ki
174 // as this is elastic scattering.
175
176 fs->addModifiedParticle(particle1);
177 fs->addModifiedParticle(particle2);
178
179 }
180
181 }
182