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25 // 25 //
26 // G4IonCoulombCrossSection.cc 26 // G4IonCoulombCrossSection.cc
27 //-------------------------------------------- 27 //-------------------------------------------------------------------
28 // 28 //
29 // GEANT4 Class header file 29 // GEANT4 Class header file
30 // 30 //
31 // File name: G4IonCoulombCrossSection 31 // File name: G4IonCoulombCrossSection
32 // 32 //
33 // Author: Cristina Consolandi 33 // Author: Cristina Consolandi
34 // 34 //
35 // Creation date: 05.10.2010 from G4eCoulombSc 35 // Creation date: 05.10.2010 from G4eCoulombScatteringModel
36 // 36 //
37 // Class Description: 37 // Class Description:
38 // Computation of Screen-Coulomb Cross Sectio 38 // Computation of Screen-Coulomb Cross Section
39 // for protons, alpha and heavy Ions 39 // for protons, alpha and heavy Ions
40 // 40 //
41 // 41 //
42 // Reference: 42 // Reference:
43 // M.J. Boschini et al. "Nuclear and Non- 43 // M.J. Boschini et al. "Nuclear and Non-Ionizing Energy-Loss
44 // for Coulomb Scattered Particles from L 44 // for Coulomb Scattered Particles from Low Energy up to Relativistic
45 // Regime in Space Radiation Environment" 45 // Regime in Space Radiation Environment"
46 // Accepted for publication in the Procee 46 // Accepted for publication in the Proceedings of the ICATPP Conference
47 // on Cosmic Rays for Particle and Astrop 47 // on Cosmic Rays for Particle and Astroparticle Physics, Villa Olmo, 7-8
48 // October, 2010, to be published by Wor 48 // October, 2010, to be published by World Scientific (Singapore).
49 // 49 //
50 // Available for downloading at: 50 // Available for downloading at:
51 // http://arxiv.org/abs/1011.4822 51 // http://arxiv.org/abs/1011.4822
52 // 52 //
53 // ------------------------------------------- 53 // -------------------------------------------------------------------
54 // 54 //
55 //....oooOO0OOooo........oooOO0OOooo........oo 55 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
56 <<
57 #include "G4IonCoulombCrossSection.hh" 56 #include "G4IonCoulombCrossSection.hh"
58 #include "G4PhysicalConstants.hh" <<
59 #include "Randomize.hh" 57 #include "Randomize.hh"
60 #include "G4Proton.hh" 58 #include "G4Proton.hh"
61 #include "G4Exp.hh" << 59 #include "G4LossTableManager.hh"
62 #include "G4Log.hh" <<
63 60
64 //....oooOO0OOooo........oooOO0OOooo........oo 61 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
65 62
66 using namespace std; <<
67 63
68 const G4double a0 = CLHEP::electron_mass_c2/0. << 64 using namespace std;
69 65
70 G4IonCoulombCrossSection::G4IonCoulombCrossSec 66 G4IonCoulombCrossSection::G4IonCoulombCrossSection():
71 cosThetaMin(1.0), 67 cosThetaMin(1.0),
72 cosThetaMax(-1.0), 68 cosThetaMax(-1.0),
73 alpha2(fine_structure_const*fine_structure_ 69 alpha2(fine_structure_const*fine_structure_const)
74 { 70 {
75 fNistManager = G4NistManager::Instance(); << 71 fNistManager = G4NistManager::Instance();
76 fG4pow = G4Pow::GetInstance(); << 72 theProton = G4Proton::Proton();
77 theProton = G4Proton::Proton(); << 73 particle=0;
78 particle = nullptr; << 74
79 << 75 G4double p0 = electron_mass_c2*classic_electr_radius;
80 G4double p0 = electron_mass_c2*classic_elect << 76 coeff = twopi*p0*p0;
81 coeff = twopi*p0*p0; << 77
82 << 78 cosTetMinNuc=0;
83 cosTetMinNuc=0; << 79 cosTetMaxNuc=0;
84 cosTetMaxNuc=0; << 80 nucXSection =0;
85 nucXSection =0; << 81
86 82
87 chargeSquare = spin = mass = 0.0; << 83 chargeSquare = spin = mass =0;
88 tkinLab = momLab2 = invbetaLab2 = tkin = mom << 84 tkinLab = momLab2 = invbetaLab2=0;
>> 85 tkin = mom2 = invbeta2=0;
>> 86
>> 87 targetZ = targetMass = screenZ =0;
>> 88 ScreenRSquare=0.;
>> 89
>> 90 etag = ecut = 0.0;
89 91
90 targetZ = targetMass = screenZ = ScreenRSqua <<
91 } 92 }
>> 93 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
92 94
>> 95 G4IonCoulombCrossSection::~G4IonCoulombCrossSection()
>> 96 {}
93 //....oooOO0OOooo........oooOO0OOooo........oo 97 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
94 98
95 void G4IonCoulombCrossSection::Initialise(cons 99 void G4IonCoulombCrossSection::Initialise(const G4ParticleDefinition* p,
96 G4do 100 G4double CosThetaLim)
97 { 101 {
98 SetupParticle(p); <<
99 nucXSection = tkin = targetZ = mom2 = 0.0; <<
100 etag = DBL_MAX; <<
101 particle = p; <<
102 cosThetaMin = CosThetaLim; <<
103 } <<
104 102
>> 103 SetupParticle(p);
>> 104 nucXSection = 0.0;
>> 105 tkin = targetZ = mom2 = DBL_MIN;
>> 106 ecut = etag = DBL_MAX;
>> 107 particle = p;
>> 108
>> 109
>> 110 cosThetaMin = CosThetaLim;
>> 111
>> 112 }
105 //....oooOO0OOooo........oooOO0OOooo........oo 113 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
106 114
107 void G4IonCoulombCrossSection::SetupKinematic( << 115 void G4IonCoulombCrossSection::SetupKinematic(G4double ekin,
>> 116 G4double cut,G4int iz )
108 { 117 {
109 if(ekin != tkinLab || tmass != targetMass) { << 118 if(ekin != tkinLab || ecut != cut) {
>> 119
>> 120 // lab
>> 121 tkinLab = ekin;
>> 122 momLab2 = tkinLab*(tkinLab + 2.0*mass);
>> 123 invbetaLab2 = 1.0 + mass*mass/momLab2;
110 124
111 // lab << 125 G4double etot = tkinLab + mass;
112 tkinLab = ekin; << 126 G4double ptot = sqrt(momLab2);
113 momLab2 = tkinLab*(tkinLab + 2.0*mass); << 127 G4double m12 = mass*mass;
114 invbetaLab2 = 1.0 + mass*mass/momLab2; <<
115 128
116 G4double etot = tkinLab + mass; << 129 targetMass=fNistManager->GetAtomicMassAmu(iz)*amu_c2;
117 G4double ptot = sqrt(momLab2); << 130 G4double m2 = targetMass;
118 G4double m12 = mass*mass; << 131
119 // relativistic reduced mass from publucat << 132 // relativistic reduced mass from publucation
120 // A.P. Martynenko, R.N. Faustov, Teoret. << 133 // A.P. Martynenko, R.N. Faustov, Teoret. mat. Fiz. 64 (1985) 179
121 134
122 //incident particle & target nucleus << 135 //incident particle & target nucleus
123 targetMass = tmass; << 136 G4double Ecm=sqrt(m12 + m2*m2 + 2.0*etot*m2);
124 G4double Ecm=sqrt(m12 + targetMass*targetM << 137 G4double mu_rel=mass*m2/Ecm;
125 G4double mu_rel=mass*targetMass/Ecm; << 138 G4double momCM= ptot*m2/Ecm;
126 G4double momCM= ptot*targetMass/Ecm; << 139 // relative system
127 // relative system << 140 mom2 = momCM*momCM;
128 mom2 = momCM*momCM; << 141 invbeta2 = 1.0 + mu_rel*mu_rel/mom2;
129 invbeta2 = 1.0 + mu_rel*mu_rel/mom2; << 142 tkin = momCM*sqrt(invbeta2) - mu_rel;//Ekin of mu_rel
130 tkin = momCM*sqrt(invbeta2) - mu_rel;//Eki << 143 //.........................................................
131 <<
132 cosTetMinNuc = cosThetaMin; <<
133 cosTetMaxNuc = cosThetaMax; <<
134 } <<
135 } <<
136 144
>> 145 cosTetMinNuc = cosThetaMin;
>> 146 cosTetMaxNuc = cosThetaMax;
>> 147
>> 148 }
>> 149
>> 150 }
137 //....oooOO0OOooo........oooOO0OOooo........oo 151 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
138 152
139 void G4IonCoulombCrossSection::SetupTarget(G4d << 153
140 G4int) << 154 void G4IonCoulombCrossSection::SetupTarget(G4double Z, G4double e, G4int heavycorr)
141 { << 155 {
142 if(Z != targetZ || e != etag) { << 156 if(Z != targetZ || e != etag) {
143 etag = e; << 157 etag = e;
144 targetZ = Z; << 158 targetZ = Z;
145 G4int iz= G4lrint(Z); << 159 G4int iz= G4int(Z);
146 << 160
147 SetScreenRSquare(iz); << 161 SetScreenRSquare(iz);
148 screenZ = 0; << 162 screenZ =0;
149 screenZ = ScreenRSquare/mom2; << 163 screenZ = ScreenRSquare/mom2;
150 //heavycorr = 0; << 164
151 // G4cout<< "heavycorr "<<heavycorr<<G4en << 165 // G4cout<< "heavycorr "<<heavycorr<<G4endl;
152 << 166
153 G4double corr=5.*twopi*Z*std::sqrt(chargeS << 167 if(heavycorr!=0 && particle != theProton){
154 corr=G4Exp(G4Log(corr)*0.04); << 168 G4double corr=5.*twopi*Z*std::sqrt(chargeSquare*alpha2);
155 screenZ *=0.5*(1.13 + corr*3.76*Z*Z*charge << 169 corr=std::pow(corr,0.12);
156 // G4cout<<" heavycorr Z e corr....2As "<< << 170 screenZ *=(1.13 + corr*3.76*Z*Z*chargeSquare*invbeta2*alpha2)/2.;
157 // <<Z <<"\t"<<e/MeV <<"\t"<<screenZ<<G4e << 171 // G4cout<<" heavycorr Z e corr....2As "<< heavycorr << "\t"
158 << 172 // <<Z <<"\t"<<e/MeV <<"\t"<<screenZ<<G4endl;
159 if(1 == iz && particle == theProton && cos << 173
160 cosTetMaxNuc = 0.0; << 174 }else{ screenZ *=(1.13 + 3.76*Z*Z*chargeSquare*invbeta2*alpha2)/2.;
161 } << 175 // G4cout<<" heavycorr Z e....2As "<< heavycorr << "\t"
162 } << 176 // <<Z <<"\t"<< e/MeV <<"\t" <<screenZ<<G4endl;
>> 177 }
>> 178
>> 179 if(1 == iz && particle == theProton && cosTetMaxNuc < 0.0) {
>> 180 cosTetMaxNuc = 0.0;
>> 181 }
>> 182
>> 183 }
163 } 184 }
164 185
165 //....oooOO0OOooo........oooOO0OOooo........oo 186 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
>> 187 void G4IonCoulombCrossSection::SetScreenRSquare(G4int iz){
166 188
167 void G4IonCoulombCrossSection::SetScreenRSquar << 189 G4double a0 = electron_mass_c2/0.88534;
168 { <<
169 //for proton Thomas-Fermi screening length <<
170 G4int Z1 = G4lrint(std::sqrt(chargeSquare)); <<
171 G4double Z113 = fG4pow->Z13(iz); <<
172 G4double Z1023 = fG4pow->powZ(Z1,0.23); <<
173 G4double Z2023 = fG4pow->powZ(iz,0.23); <<
174 G4double x=a0*(Z1023+Z2023); <<
175 <<
176 // Universal screening length <<
177 if(particle == theProton){ <<
178 x = a0*Z113; <<
179 } <<
180 190
181 ScreenRSquare = alpha2*x*x; << 191 //target nucleus
182 } << 192 G4double Z1=std::sqrt(chargeSquare);
>> 193 G4double Z2=targetZ;
>> 194
>> 195 G4double Z1023=std::pow(Z1,0.23);
>> 196 G4double Z2023=std::pow(Z2,0.23);
>> 197
>> 198 // Universal screening length
>> 199 G4double x=a0*(Z1023+Z2023);
>> 200
>> 201 //for proton Thomas-Fermi screening length
>> 202 if(particle == theProton){
>> 203 x = a0*fNistManager->GetZ13(iz);
>> 204 }
>> 205 ScreenRSquare = alpha2*x*x;
183 206
>> 207
>> 208 }
184 //....oooOO0OOooo........oooOO0OOooo........oo 209 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
185 210
186 G4double G4IonCoulombCrossSection::NuclearCros 211 G4double G4IonCoulombCrossSection::NuclearCrossSection()
187 { 212 {
188 // This method needs initialisation before b << 213 // This method needs initialisation before be called
189 // scattering with target nucleus << 214
190 G4double fac = coeff*targetZ*(targetZ)*charg << 215 // scattering with target nucleus
191 << 216 G4double fac = coeff*targetZ*targetZ*chargeSquare*invbeta2/mom2;
192 nucXSection = 0.0; << 217
193 << 218 nucXSection = 0.0;
194 G4double x = 1.0 - cosTetMinNuc; << 219
195 G4double x1 = x + screenZ; << 220 G4double x = 1.0 - cosTetMinNuc;
196 << 221 G4double x1 = x + screenZ;
197 // scattering with nucleus << 222
198 if(cosTetMaxNuc < cosTetMinNuc) { << 223 // scattering with nucleus
199 nucXSection = fac*(cosTetMinNuc - cosTetMa << 224 if(cosTetMaxNuc < cosTetMinNuc) {
200 (x1*(1.0 - cosTetMaxNuc + screenZ)); << 225
201 } << 226 nucXSection =fac*(cosTetMinNuc - cosTetMaxNuc)/
>> 227 (x1*(1.0 - cosTetMaxNuc + screenZ));
>> 228
>> 229 }
202 230
203 return nucXSection; 231 return nucXSection;
204 } 232 }
205 233
206 //....oooOO0OOooo........oooOO0OOooo........oo 234 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
207 235
208 G4double G4IonCoulombCrossSection::SampleCosin 236 G4double G4IonCoulombCrossSection::SampleCosineTheta()
209 { << 237 {
210 G4double z1 = 0.0; << 238
211 if(cosTetMaxNuc < cosTetMinNuc) { << 239 if(cosTetMaxNuc >= cosTetMinNuc) return 0.0;
212 << 240
213 G4double x1 = 1. - cosTetMinNuc + screenZ; << 241 G4double x1 = 1. - cosTetMinNuc + screenZ;
214 G4double x2 = 1. - cosTetMaxNuc + screenZ; << 242 G4double x2 = 1. - cosTetMaxNuc + screenZ;
215 G4double dx = cosTetMinNuc - cosTetMaxNuc; << 243 G4double dx = cosTetMinNuc - cosTetMaxNuc;
216 z1 = x1*x2/(x1 + G4UniformRand()*dx) - scr << 244 G4double grej, z1;
217 } << 245
>> 246 z1 = x1*x2/(x1 + G4UniformRand()*dx) - screenZ;
>> 247 grej = 1.0/(1.0 + z1);
>> 248
>> 249
218 return z1; 250 return z1;
219 } 251 }
220 252
221 //....oooOO0OOooo........oooOO0OOooo........oo 253 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
222 254
223 255
224 256
225 257
226 258