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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 56
57 #include "G4IonCoulombCrossSection.hh" 57 #include "G4IonCoulombCrossSection.hh"
58 #include "G4PhysicalConstants.hh" 58 #include "G4PhysicalConstants.hh"
59 #include "Randomize.hh" 59 #include "Randomize.hh"
60 #include "G4Proton.hh" 60 #include "G4Proton.hh"
61 #include "G4Exp.hh" 61 #include "G4Exp.hh"
62 #include "G4Log.hh" 62 #include "G4Log.hh"
63 63
64 //....oooOO0OOooo........oooOO0OOooo........oo 64 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
65 65
66 using namespace std; 66 using namespace std;
67 67
68 const G4double a0 = CLHEP::electron_mass_c2/0. 68 const G4double a0 = CLHEP::electron_mass_c2/0.88534;
69 69
70 G4IonCoulombCrossSection::G4IonCoulombCrossSec 70 G4IonCoulombCrossSection::G4IonCoulombCrossSection():
71 cosThetaMin(1.0), 71 cosThetaMin(1.0),
72 cosThetaMax(-1.0), 72 cosThetaMax(-1.0),
73 alpha2(fine_structure_const*fine_structure_ 73 alpha2(fine_structure_const*fine_structure_const)
74 { 74 {
75 fNistManager = G4NistManager::Instance(); 75 fNistManager = G4NistManager::Instance();
76 fG4pow = G4Pow::GetInstance(); <<
77 theProton = G4Proton::Proton(); 76 theProton = G4Proton::Proton();
78 particle = nullptr; << 77 particle=0;
79 78
80 G4double p0 = electron_mass_c2*classic_elect 79 G4double p0 = electron_mass_c2*classic_electr_radius;
81 coeff = twopi*p0*p0; 80 coeff = twopi*p0*p0;
82 81
83 cosTetMinNuc=0; 82 cosTetMinNuc=0;
84 cosTetMaxNuc=0; 83 cosTetMaxNuc=0;
85 nucXSection =0; 84 nucXSection =0;
86 85
87 chargeSquare = spin = mass = 0.0; 86 chargeSquare = spin = mass = 0.0;
88 tkinLab = momLab2 = invbetaLab2 = tkin = mom 87 tkinLab = momLab2 = invbetaLab2 = tkin = mom2 = invbeta2 = 0.0;
89 88
90 targetZ = targetMass = screenZ = ScreenRSqua << 89 targetZ = targetMass = screenZ = ScreenRSquare = etag = ecut = 0.0;
91 } 90 }
>> 91 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
>> 92
>> 93 G4IonCoulombCrossSection::~G4IonCoulombCrossSection()
>> 94 {}
92 95
93 //....oooOO0OOooo........oooOO0OOooo........oo 96 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
94 97
95 void G4IonCoulombCrossSection::Initialise(cons 98 void G4IonCoulombCrossSection::Initialise(const G4ParticleDefinition* p,
96 G4do 99 G4double CosThetaLim)
97 { 100 {
98 SetupParticle(p); 101 SetupParticle(p);
99 nucXSection = tkin = targetZ = mom2 = 0.0; << 102 nucXSection = 0.0;
100 etag = DBL_MAX; << 103 tkin = targetZ = mom2 = DBL_MIN;
>> 104 ecut = etag = DBL_MAX;
101 particle = p; 105 particle = p;
102 cosThetaMin = CosThetaLim; 106 cosThetaMin = CosThetaLim;
103 } 107 }
104 108
105 //....oooOO0OOooo........oooOO0OOooo........oo 109 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
106 110
107 void G4IonCoulombCrossSection::SetupKinematic( << 111 void G4IonCoulombCrossSection::SetupKinematic(G4double ekin,
>> 112 G4double cut, G4double tmass)
108 { 113 {
109 if(ekin != tkinLab || tmass != targetMass) { << 114 if(ekin != tkinLab || ecut != cut || tmass != targetMass) {
110 115
111 // lab 116 // lab
112 tkinLab = ekin; 117 tkinLab = ekin;
113 momLab2 = tkinLab*(tkinLab + 2.0*mass); 118 momLab2 = tkinLab*(tkinLab + 2.0*mass);
114 invbetaLab2 = 1.0 + mass*mass/momLab2; 119 invbetaLab2 = 1.0 + mass*mass/momLab2;
115 120
116 G4double etot = tkinLab + mass; 121 G4double etot = tkinLab + mass;
117 G4double ptot = sqrt(momLab2); 122 G4double ptot = sqrt(momLab2);
118 G4double m12 = mass*mass; 123 G4double m12 = mass*mass;
>> 124
>> 125 targetMass = tmass;
119 // relativistic reduced mass from publucat 126 // relativistic reduced mass from publucation
120 // A.P. Martynenko, R.N. Faustov, Teoret. 127 // A.P. Martynenko, R.N. Faustov, Teoret. mat. Fiz. 64 (1985) 179
121 128
122 //incident particle & target nucleus 129 //incident particle & target nucleus
123 targetMass = tmass; <<
124 G4double Ecm=sqrt(m12 + targetMass*targetM 130 G4double Ecm=sqrt(m12 + targetMass*targetMass + 2.0*etot*targetMass);
125 G4double mu_rel=mass*targetMass/Ecm; 131 G4double mu_rel=mass*targetMass/Ecm;
126 G4double momCM= ptot*targetMass/Ecm; 132 G4double momCM= ptot*targetMass/Ecm;
127 // relative system 133 // relative system
128 mom2 = momCM*momCM; 134 mom2 = momCM*momCM;
129 invbeta2 = 1.0 + mu_rel*mu_rel/mom2; 135 invbeta2 = 1.0 + mu_rel*mu_rel/mom2;
130 tkin = momCM*sqrt(invbeta2) - mu_rel;//Eki 136 tkin = momCM*sqrt(invbeta2) - mu_rel;//Ekin of mu_rel
131 137
132 cosTetMinNuc = cosThetaMin; 138 cosTetMinNuc = cosThetaMin;
133 cosTetMaxNuc = cosThetaMax; 139 cosTetMaxNuc = cosThetaMax;
134 } 140 }
135 } 141 }
136 142
137 //....oooOO0OOooo........oooOO0OOooo........oo 143 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
138 144
139 void G4IonCoulombCrossSection::SetupTarget(G4d 145 void G4IonCoulombCrossSection::SetupTarget(G4double Z, G4double e,
140 G4int) << 146 G4int heavycorr)
141 { 147 {
142 if(Z != targetZ || e != etag) { 148 if(Z != targetZ || e != etag) {
143 etag = e; 149 etag = e;
144 targetZ = Z; 150 targetZ = Z;
145 G4int iz= G4lrint(Z); 151 G4int iz= G4lrint(Z);
146 152
147 SetScreenRSquare(iz); 153 SetScreenRSquare(iz);
148 screenZ = 0; 154 screenZ = 0;
149 screenZ = ScreenRSquare/mom2; 155 screenZ = ScreenRSquare/mom2;
150 //heavycorr = 0; <<
151 // G4cout<< "heavycorr "<<heavycorr<<G4en 156 // G4cout<< "heavycorr "<<heavycorr<<G4endl;
152 157
153 G4double corr=5.*twopi*Z*std::sqrt(chargeS << 158 if(heavycorr!=0 && particle != theProton){
154 corr=G4Exp(G4Log(corr)*0.04); << 159 G4double corr=5.*twopi*Z*std::sqrt(chargeSquare*alpha2);
155 screenZ *=0.5*(1.13 + corr*3.76*Z*Z*charge << 160 corr=G4Exp(G4Log(corr)*0.12);
156 // G4cout<<" heavycorr Z e corr....2As "<< << 161 screenZ *=0.5*(1.13 + corr*3.76*Z*Z*chargeSquare*invbeta2*alpha2);
157 // <<Z <<"\t"<<e/MeV <<"\t"<<screenZ<<G4e << 162 // G4cout<<" heavycorr Z e corr....2As "<< heavycorr << "\t"
158 << 163 // <<Z <<"\t"<<e/MeV <<"\t"<<screenZ<<G4endl;
>> 164 }else{
>> 165 screenZ *= 0.5*(1.13 + 3.76*Z*Z*chargeSquare*invbeta2*alpha2);
>> 166 // G4cout<<" heavycorr Z e....2As "<< heavycorr << "\t"
>> 167 // <<Z <<"\t"<< e/MeV <<"\t" <<screenZ<<G4endl;
>> 168 }
>> 169
159 if(1 == iz && particle == theProton && cos 170 if(1 == iz && particle == theProton && cosTetMaxNuc < 0.0) {
160 cosTetMaxNuc = 0.0; 171 cosTetMaxNuc = 0.0;
161 } 172 }
162 } 173 }
163 } 174 }
164 175
165 //....oooOO0OOooo........oooOO0OOooo........oo 176 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
166 177
167 void G4IonCoulombCrossSection::SetScreenRSquar 178 void G4IonCoulombCrossSection::SetScreenRSquare(G4int iz)
168 { 179 {
169 //for proton Thomas-Fermi screening length << 180 //for proton Thomas-Fermi screening length
170 G4int Z1 = G4lrint(std::sqrt(chargeSquare)); 181 G4int Z1 = G4lrint(std::sqrt(chargeSquare));
171 G4double Z113 = fG4pow->Z13(iz); << 182 G4double Z1023 = G4Exp(fNistManager->GetLOGZ(Z1)*0.23);
172 G4double Z1023 = fG4pow->powZ(Z1,0.23); << 183 G4double Z2023 = G4Exp(fNistManager->GetLOGZ(iz)*0.23);
173 G4double Z2023 = fG4pow->powZ(iz,0.23); << 184
174 G4double x=a0*(Z1023+Z2023); <<
175 <<
176 // Universal screening length 185 // Universal screening length
177 if(particle == theProton){ << 186 G4double x = a0*(Z1023+Z2023);
178 x = a0*Z113; <<
179 } <<
180 187
181 ScreenRSquare = alpha2*x*x; << 188 ScreenRSquare = alpha2*x*x;
182 } 189 }
183 190
184 //....oooOO0OOooo........oooOO0OOooo........oo 191 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
185 192
186 G4double G4IonCoulombCrossSection::NuclearCros 193 G4double G4IonCoulombCrossSection::NuclearCrossSection()
187 { 194 {
188 // This method needs initialisation before b 195 // This method needs initialisation before be called
189 // scattering with target nucleus 196 // scattering with target nucleus
190 G4double fac = coeff*targetZ*(targetZ)*charg << 197 G4double fac = coeff*targetZ*(targetZ + 1)*chargeSquare*invbeta2/mom2;
191 198
192 nucXSection = 0.0; 199 nucXSection = 0.0;
193 200
194 G4double x = 1.0 - cosTetMinNuc; 201 G4double x = 1.0 - cosTetMinNuc;
195 G4double x1 = x + screenZ; 202 G4double x1 = x + screenZ;
196 203
197 // scattering with nucleus 204 // scattering with nucleus
198 if(cosTetMaxNuc < cosTetMinNuc) { 205 if(cosTetMaxNuc < cosTetMinNuc) {
199 nucXSection = fac*(cosTetMinNuc - cosTetMa 206 nucXSection = fac*(cosTetMinNuc - cosTetMaxNuc)/
200 (x1*(1.0 - cosTetMaxNuc + screenZ)); 207 (x1*(1.0 - cosTetMaxNuc + screenZ));
201 } 208 }
202 209
203 return nucXSection; 210 return nucXSection;
204 } 211 }
205 212
206 //....oooOO0OOooo........oooOO0OOooo........oo 213 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
207 214
208 G4double G4IonCoulombCrossSection::SampleCosin 215 G4double G4IonCoulombCrossSection::SampleCosineTheta()
209 { 216 {
210 G4double z1 = 0.0; 217 G4double z1 = 0.0;
211 if(cosTetMaxNuc < cosTetMinNuc) { 218 if(cosTetMaxNuc < cosTetMinNuc) {
212 219
213 G4double x1 = 1. - cosTetMinNuc + screenZ; 220 G4double x1 = 1. - cosTetMinNuc + screenZ;
214 G4double x2 = 1. - cosTetMaxNuc + screenZ; 221 G4double x2 = 1. - cosTetMaxNuc + screenZ;
215 G4double dx = cosTetMinNuc - cosTetMaxNuc; 222 G4double dx = cosTetMinNuc - cosTetMaxNuc;
216 z1 = x1*x2/(x1 + G4UniformRand()*dx) - scr 223 z1 = x1*x2/(x1 + G4UniformRand()*dx) - screenZ;
217 } 224 }
218 return z1; 225 return z1;
219 } 226 }
220 227
221 //....oooOO0OOooo........oooOO0OOooo........oo 228 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
222 229
223 230
224 231
225 232
226 233