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25 // 25 //
26 // INCL++ intra-nuclear cascade model 26 // INCL++ intra-nuclear cascade model
27 // Alain Boudard, CEA-Saclay, France << 27 // Pekka Kaitaniemi, CEA and Helsinki Institute of Physics
28 // Joseph Cugnon, University of Liege, Belgium << 28 // Davide Mancusi, CEA
29 // Jean-Christophe David, CEA-Saclay, France << 29 // Alain Boudard, CEA
30 // Pekka Kaitaniemi, CEA-Saclay, France, and H << 30 // Sylvie Leray, CEA
31 // Sylvie Leray, CEA-Saclay, France << 31 // Joseph Cugnon, University of Liege
32 // Davide Mancusi, CEA-Saclay, France <<
33 // 32 //
34 #define INCLXX_IN_GEANT4_MODE 1 33 #define INCLXX_IN_GEANT4_MODE 1
35 34
36 #include "globals.hh" 35 #include "globals.hh"
37 36
38 #include "G4INCLElasticChannel.hh" 37 #include "G4INCLElasticChannel.hh"
39 #include "G4INCLRandom.hh" 38 #include "G4INCLRandom.hh"
40 #include "G4INCLKinematicsUtils.hh" 39 #include "G4INCLKinematicsUtils.hh"
41 #include "G4INCLParticleTable.hh" 40 #include "G4INCLParticleTable.hh"
42 #include "G4INCLCrossSections.hh" 41 #include "G4INCLCrossSections.hh"
43 #include "G4INCLGlobals.hh" 42 #include "G4INCLGlobals.hh"
44 43
45 namespace G4INCL { 44 namespace G4INCL {
46 45
47 ElasticChannel::ElasticChannel(Particle *p1, << 46 ElasticChannel::ElasticChannel(Nucleus *n, Particle *p1, Particle *p2)
48 :particle1(p1), particle2(p2) << 47 :theNucleus(n), particle1(p1), particle2(p2)
49 { 48 {
50 } 49 }
51 50
52 ElasticChannel::~ElasticChannel() 51 ElasticChannel::~ElasticChannel()
53 { 52 {
54 } 53 }
55 54
56 void ElasticChannel::fillFinalState(FinalSta << 55 FinalState* ElasticChannel::getFinalState()
57 { 56 {
58 ParticleType p1TypeOld = particle1->getTyp 57 ParticleType p1TypeOld = particle1->getType();
59 ParticleType p2TypeOld = particle2->getTyp 58 ParticleType p2TypeOld = particle2->getType();
60 59
61 /* Concerning the way we calculate the lab 60 /* Concerning the way we calculate the lab momentum, see the considerations
62 * in CrossSections::elasticNNLegacy(). 61 * in CrossSections::elasticNNLegacy().
63 */ 62 */
64 const G4double s = KinematicsUtils::square 63 const G4double s = KinematicsUtils::squareTotalEnergyInCM(particle1, particle2);
65 const G4double pl = KinematicsUtils::momen 64 const G4double pl = KinematicsUtils::momentumInLab(s, ParticleTable::effectiveNucleonMass, ParticleTable::effectiveNucleonMass);
66 65
67 const G4int isospin = ParticleTable::getIs 66 const G4int isospin = ParticleTable::getIsospin(particle1->getType()) +
68 ParticleTable::getIsospin(particle2->get 67 ParticleTable::getIsospin(particle2->getType());
69 68
70 // Calculate the outcome of the channel: 69 // Calculate the outcome of the channel:
71 G4double psq = particle1->getMomentum().ma 70 G4double psq = particle1->getMomentum().mag2();
72 G4double pnorm = std::sqrt(psq); 71 G4double pnorm = std::sqrt(psq);
73 G4double b = CrossSections::calculateNNAng << 72 G4double b = CrossSections::calculateNNDiffCrossSection(pl, isospin);
74 G4double btmax = 4.0 * psq * b; 73 G4double btmax = 4.0 * psq * b;
75 G4double z = std::exp(-btmax); 74 G4double z = std::exp(-btmax);
76 G4double ranres = Random::shoot(); 75 G4double ranres = Random::shoot();
77 G4double y = 1.0 - ranres * (1.0 - z); 76 G4double y = 1.0 - ranres * (1.0 - z);
78 G4double T = std::log(y)/b; 77 G4double T = std::log(y)/b;
79 G4int iexpi = 0; 78 G4int iexpi = 0;
80 G4double apt = 1.0; 79 G4double apt = 1.0;
81 80
82 // Handle np case 81 // Handle np case
83 if((particle1->getType() == Proton && part 82 if((particle1->getType() == Proton && particle2->getType() == Neutron) ||
84 (particle1->getType() == Neutron && par << 83 (particle1->getType() == Neutron && particle2->getType() == Proton)) {
85 if(pl > 800.0) { 84 if(pl > 800.0) {
86 const G4double x = 0.001 * pl; // Tran 85 const G4double x = 0.001 * pl; // Transform to GeV
87 apt = (800.0/pl)*(800.0/pl); 86 apt = (800.0/pl)*(800.0/pl);
88 G4double cpt = std::max(6.23 * std::ex 87 G4double cpt = std::max(6.23 * std::exp(-1.79*x), 0.3);
89 G4double alphac = 100.0 * 1.0e-6; 88 G4double alphac = 100.0 * 1.0e-6;
90 G4double aaa = (1 + apt) * (1 - std::e 89 G4double aaa = (1 + apt) * (1 - std::exp(-btmax))/b;
91 G4double argu = psq * alphac; 90 G4double argu = psq * alphac;
92 91
93 if(argu >= 8) { 92 if(argu >= 8) {
94 argu = 0.0; 93 argu = 0.0;
95 } else { 94 } else {
96 argu = std::exp(-4.0 * argu); 95 argu = std::exp(-4.0 * argu);
97 } 96 }
98 97
99 G4double aac = cpt * (1.0 - argu)/alph 98 G4double aac = cpt * (1.0 - argu)/alphac;
100 G4double fracpn = aaa/(aac + aaa); 99 G4double fracpn = aaa/(aac + aaa);
101 if(Random::shoot() > fracpn) { 100 if(Random::shoot() > fracpn) {
102 z = std::exp(-4.0 * psq *alphac); 101 z = std::exp(-4.0 * psq *alphac);
103 iexpi = 1; 102 iexpi = 1;
104 y = 1.0 - ranres*(1.0 - z); 103 y = 1.0 - ranres*(1.0 - z);
105 T = std::log(y)/alphac; 104 T = std::log(y)/alphac;
106 } 105 }
107 } 106 }
108 } 107 }
109 108
110 G4double ctet = 1.0 + 0.5*T/psq; 109 G4double ctet = 1.0 + 0.5*T/psq;
111 if(std::abs(ctet) > 1.0) ctet = Math::sign 110 if(std::abs(ctet) > 1.0) ctet = Math::sign(ctet);
112 G4double stet = std::sqrt(1.0 - ctet*ctet) 111 G4double stet = std::sqrt(1.0 - ctet*ctet);
113 G4double rndm = Random::shoot(); 112 G4double rndm = Random::shoot();
114 113
115 G4double fi = Math::twoPi * rndm; 114 G4double fi = Math::twoPi * rndm;
116 G4double cfi = std::cos(fi); 115 G4double cfi = std::cos(fi);
117 G4double sfi = std::sin(fi); 116 G4double sfi = std::sin(fi);
118 117
119 G4double xx = particle1->getMomentum().per 118 G4double xx = particle1->getMomentum().perp2();
120 G4double zz = std::pow(particle1->getMomen 119 G4double zz = std::pow(particle1->getMomentum().getZ(), 2);
121 120
122 if(xx >= (zz * 1.0e-8)) { 121 if(xx >= (zz * 1.0e-8)) {
123 ThreeVector p = particle1->getMomentum() 122 ThreeVector p = particle1->getMomentum();
124 G4double yn = std::sqrt(xx); 123 G4double yn = std::sqrt(xx);
125 G4double zn = yn * pnorm; 124 G4double zn = yn * pnorm;
126 G4double ex[3], ey[3], ez[3]; 125 G4double ex[3], ey[3], ez[3];
127 ez[0] = p.getX() / pnorm; 126 ez[0] = p.getX() / pnorm;
128 ez[1] = p.getY() / pnorm; 127 ez[1] = p.getY() / pnorm;
129 ez[2] = p.getZ() / pnorm; 128 ez[2] = p.getZ() / pnorm;
130 129
131 // Vector Ex is chosen arbitrarily: 130 // Vector Ex is chosen arbitrarily:
132 ex[0] = p.getY() / yn; 131 ex[0] = p.getY() / yn;
133 ex[1] = -p.getX() / yn; 132 ex[1] = -p.getX() / yn;
134 ex[2] = 0.0; 133 ex[2] = 0.0;
135 134
136 ey[0] = p.getX() * p.getZ() / zn; 135 ey[0] = p.getX() * p.getZ() / zn;
137 ey[1] = p.getY() * p.getZ() / zn; 136 ey[1] = p.getY() * p.getZ() / zn;
138 ey[2] = -xx/zn; 137 ey[2] = -xx/zn;
139 138
140 G4double pX = (ex[0]*cfi*stet + ey[0]*sf 139 G4double pX = (ex[0]*cfi*stet + ey[0]*sfi*stet + ez[0]*ctet) * pnorm;
141 G4double pY = (ex[1]*cfi*stet + ey[1]*sf 140 G4double pY = (ex[1]*cfi*stet + ey[1]*sfi*stet + ez[1]*ctet) * pnorm;
142 G4double pZ = (ex[2]*cfi*stet + ey[2]*sf 141 G4double pZ = (ex[2]*cfi*stet + ey[2]*sfi*stet + ez[2]*ctet) * pnorm;
143 142
144 ThreeVector p1momentum = ThreeVector(pX, 143 ThreeVector p1momentum = ThreeVector(pX, pY, pZ);
145 particle1->setMomentum(p1momentum); 144 particle1->setMomentum(p1momentum);
146 particle2->setMomentum(-p1momentum); 145 particle2->setMomentum(-p1momentum);
147 } else { // if(xx < (zz * 1.0e-8)) { 146 } else { // if(xx < (zz * 1.0e-8)) {
148 G4double momZ = particle1->getMomentum() 147 G4double momZ = particle1->getMomentum().getZ();
149 G4double pX = momZ * cfi * stet; 148 G4double pX = momZ * cfi * stet;
150 G4double pY = momZ * sfi * stet; 149 G4double pY = momZ * sfi * stet;
151 G4double pZ = momZ * ctet; 150 G4double pZ = momZ * ctet;
152 151
153 ThreeVector p1momentum(pX, pY, pZ); 152 ThreeVector p1momentum(pX, pY, pZ);
154 particle1->setMomentum(p1momentum); 153 particle1->setMomentum(p1momentum);
155 particle2->setMomentum(-p1momentum); 154 particle2->setMomentum(-p1momentum);
156 } 155 }
157 156
158 // Handle backward scattering here. 157 // Handle backward scattering here.
159 158
160 if((particle1->getType() == Proton && part 159 if((particle1->getType() == Proton && particle2->getType() == Neutron) ||
161 (particle1->getType() == Neutron && par << 160 (particle1->getType() == Neutron && particle2->getType() == Proton)) {
162 rndm = Random::shoot(); 161 rndm = Random::shoot();
163 apt = 1.0; 162 apt = 1.0;
164 if(pl > 800.0) { 163 if(pl > 800.0) {
165 apt = std::pow(800.0/pl, 2); 164 apt = std::pow(800.0/pl, 2);
166 } 165 }
167 if(iexpi == 1 || rndm > 1.0/(1.0 + apt)) 166 if(iexpi == 1 || rndm > 1.0/(1.0 + apt)) {
168 particle1->setType(p2TypeOld); 167 particle1->setType(p2TypeOld);
169 particle2->setType(p1TypeOld); 168 particle2->setType(p1TypeOld);
170 } 169 }
171 } 170 }
172 171
173 // Note: there is no need to update the ki 172 // Note: there is no need to update the kinetic energies of the particles,
174 // as this is elastic scattering. 173 // as this is elastic scattering.
175 174
>> 175 FinalState *fs = new FinalState();
176 fs->addModifiedParticle(particle1); 176 fs->addModifiedParticle(particle1);
177 fs->addModifiedParticle(particle2); 177 fs->addModifiedParticle(particle2);
>> 178
>> 179 return fs;
178 180
179 } 181 }
180 182
181 } 183 }
182 184