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26 //
27 // Geant4 class G4NuclearRadii
28 //
29 // Author V.Ivanchenko 27.05.2019
30 //
31 //
32
33 #include "G4NuclearRadii.hh"
34 #include "G4Pow.hh"
35 #include "G4PhysicalConstants.hh"
36 #include "G4ParticleDefinition.hh"
37 #include "G4NucleiProperties.hh"
38 #include "G4IsotopeList.hh"
39 #include "G4Log.hh"
40 #include "G4Exp.hh"
41
42 G4Pow* G4NuclearRadii::fG4pow = G4Pow::GetInstance();
43
44 namespace
45 {
46 const G4double llog10 = G4Log(10.);
47 const G4double fAlpha = 0.5*CLHEP::fine_structure_const*CLHEP::hbarc;
48 const G4double fInvep = 1.0/CLHEP::eplus;
49 }
50
51 G4double G4NuclearRadii::ExplicitRadius(G4int Z, G4int A)
52 {
53 G4double R = 0.0;
54 // Special rms radii for light nucleii
55 if(Z <= 4) {
56 if(A == 1) { R = 0.895*CLHEP::fermi; }// p
57 else if(A == 2) { R = 2.13*CLHEP::fermi; }// d
58 else if(Z == 1 && A == 3) { R = 1.80*CLHEP::fermi; }// t
59 else if(Z == 2 && A == 3) { R = 1.96*CLHEP::fermi; }// He3
60 else if(Z == 2 && A == 4) { R = 1.68*CLHEP::fermi; }// He4
61 else if(Z == 3) { R = 2.40*CLHEP::fermi; }// Li7
62 else if(Z == 4) { R = 2.51*CLHEP::fermi; }// Be9
63 }
64 return R;
65 }
66
67 G4double G4NuclearRadii::Radius(G4int Z, G4int A)
68 {
69 G4double R = ExplicitRadius(Z, A);
70 if(0.0 == R) {
71 if (A <= 50) {
72 G4double y = 1.1;
73 if( A <= 15) { y = 1.26; }
74 else if( A <= 20) { y = 1.19; }
75 else if( A <= 30) { y = 1.12; }
76 G4double x = fG4pow->Z13(A);
77 R = y*(x - 1./x);
78 } else {
79 R = fG4pow->powZ(A, 0.27);
80 }
81 R *= CLHEP::fermi;
82 }
83 return R;
84 }
85
86 G4double G4NuclearRadii::RadiusRMS(G4int Z, G4int A)
87 {
88 G4double R = ExplicitRadius(Z, A);
89 if(0.0 == R) {
90 R = 1.24*fG4pow->powZ(A, 0.28)*CLHEP::fermi;
91 }
92 return R;
93 }
94
95 G4double G4NuclearRadii::RadiusNNGG(G4int Z, G4int A)
96 {
97 G4double R = ExplicitRadius(Z, A);
98 if(0.0 == R) {
99 if(A > 20) {
100 R = 1.08*fG4pow->Z13(A)*(0.85 + 0.15*G4Exp(-(G4double)(A - 21)/40.));
101 } else {
102 R = 1.08*fG4pow->Z13(A)*(1.0 + 0.3*G4Exp(-(G4double)(A - 21)/10.));
103 }
104 R *= CLHEP::fermi;
105 }
106 return R;
107 }
108
109 G4double G4NuclearRadii::RadiusECS(G4int Z, G4int A)
110 {
111 G4double R=0.;
112 const G4double c[3]={0.77329745, 1.38206072, 30.28295235};
113 const G4double c1=c[0];
114 const G4double c2=c[1];
115 const G4double c3=c[2];
116
117 // Special rms radii for light nuclei
118 if (A <= 30) {
119 G4double vn = 0.5*A + fG4pow->powN(0.028*A,2) - fG4pow->powN(0.011*A,3);
120 G4double dev = vn - (A-Z);
121 R = c1*fG4pow->Z13(A) + c2/fG4pow->Z13(A) + c3*dev*dev/(A*A);
122 } else if (A<=50){
123 G4double y = 1.1;
124 G4double x = fG4pow->Z13(A);
125 R = y*(x - 1./x);
126 }
127 return R*CLHEP::fermi;
128 }
129
130 G4double G4NuclearRadii::RadiusHNGG(G4int A)
131 {
132 G4double R = CLHEP::fermi;
133 if(A > 20) {
134 R *= 1.08*fG4pow->Z13(A)*(0.8 + 0.2*G4Exp(-(G4double)(A - 20)/20.));
135 } else {
136 R *= 1.08*fG4pow->Z13(A)*(1.0 + 0.1*G4Exp(-(G4double)(A - 20)/20.));
137 }
138 return R;
139 }
140
141 G4double G4NuclearRadii::RadiusKNGG(G4int A)
142 {
143 return 1.3*CLHEP::fermi*fG4pow->Z13(A);
144 }
145
146 G4double G4NuclearRadii::RadiusND(G4int A)
147 {
148 G4double R = CLHEP::fermi;
149 if (1 == A) {
150 R *= 0.895;
151 } else {
152 R *= fG4pow->Z13(A);
153 if (A <= 3.) { R *= 0.8; }
154 else { R *= 1.7; }
155 }
156 return R;
157 }
158
159 G4double G4NuclearRadii::RadiusCB(G4int Z, G4int A)
160 {
161 G4double R = ExplicitRadius(Z, A);
162 if(0.0 == R) {
163 G4int z = std::min(Z, 92);
164 R = r0[z]*fG4pow->Z13(A)*CLHEP::fermi;
165 }
166 return R;
167 }
168
169 G4double G4NuclearRadii::ParticleRadius(const G4ParticleDefinition* p)
170 {
171 G4double R = CLHEP::fermi;
172 G4int pdg = std::abs(p->GetPDGEncoding());
173 if(pdg == 2112 || pdg == 2212) { R *= 0.895; }
174 else if(pdg == 211) { R *= 0.663; }
175 else if(pdg == 321) { R *= 0.340; }
176 else { R *= 0.5; }
177 return R;
178 }
179
180 G4double G4NuclearRadii::CoulombFactor(
181 const G4ParticleDefinition* theParticle,
182 const G4ParticleDefinition* nucleon,
183 G4double ekin)
184 {
185 G4double tR = 0.895*CLHEP::fermi;
186 G4double pR = ParticleRadius(theParticle);
187
188 G4double pZ = theParticle->GetPDGCharge()*fInvep;
189 G4double tZ = nucleon->GetPDGCharge()*fInvep;
190
191 G4double pM = theParticle->GetPDGMass();
192 G4double tM = nucleon->GetPDGMass();
193
194 G4double pElab = ekin + pM;
195 G4double totTcm = std::sqrt(pM*pM + tM*tM + 2.*pElab*tM) - pM -tM;
196
197 G4double bC = fAlpha*pZ*tZ/(pR + tR);
198 return (totTcm > bC) ? 1. - bC/totTcm : 0.0;
199 }
200
201 G4double G4NuclearRadii::CoulombFactor(
202 G4int Z, G4int A,
203 const G4ParticleDefinition* theParticle,
204 G4double ekin)
205 {
206 G4double tR = RadiusCB(Z, A);
207 G4double pR = ParticleRadius(theParticle);
208
209 G4double pZ = theParticle->GetPDGCharge()*fInvep;
210
211 G4double pM = theParticle->GetPDGMass();
212 G4double tM = G4NucleiProperties::GetNuclearMass(A, Z);
213
214 G4double pElab = ekin + pM;
215 G4double totTcm = std::sqrt(pM*pM + tM*tM + 2.*pElab*tM) - pM -tM;
216
217 G4double bC = fAlpha*pZ*Z/(pR + tR);
218 return (totTcm > bC) ? 1. - bC/totTcm : 0.0;
219 }
220
221 G4double
222 G4NuclearRadii::NeutronInelasticShape(G4int Z, G4double ekin)
223 {
224 G4double A = (Z < 100) ? aeff[Z] : aeff[100];
225 G4double elog = G4Log(ekin/CLHEP::GeV)/llog10;
226 G4double p3 = 0.6 + 13./A - 0.0005*A;
227 G4double p4 = 7.2449 - 0.018242*A;
228 G4double p5 = 1.36 + 1.8/A + 0.0005*A;
229 G4double p6 = 1. + 200./A + 0.02*A;
230 G4double p7 = 3.0 - (A - 70.)*(A - 200.)/11000.;
231
232 G4double firstexp = G4Exp(-p4*(elog + p5));
233 G4double secondexp = G4Exp(-p6*(elog + p7));
234
235 return (1. + p3*firstexp/(1. + firstexp))/(1. + secondexp);
236 }
237
238 G4double
239 G4NuclearRadii::ProtonInelasticShape(G4int Z, G4double ekin)
240 {
241 G4double A = (Z < 100) ? aeff[Z] : aeff[100];
242 G4double elog = G4Log(ekin/CLHEP::GeV)/llog10;
243 G4double ff1 = 5.6 - 0.016*A; // slope of the drop at medium energies.
244 G4double ff2 = 1.37 + 1.37/A; // start of the slope.
245 G4double ff3 = 0.8 + 18./A - 0.002*A; // stephight
246 G4double res = (1.0 + ff3*(1.0 - (1.0/(1+G4Exp(-ff1*(elog + ff2))))));
247 ff1 = 8. - 8./A - 0.008*A; // slope of the rise
248 ff2 = 2.34 - 5.4/A - 0.0028*A; // start of the rise
249 res /= (1.0 + G4Exp(-ff1*(elog + ff2)));
250 return res;
251 }
252
253 const G4double G4NuclearRadii::r0[] = {
254 1.2,
255 1.3, 1.3, 1.3, 1.3,1.17,1.54,1.65,1.71, 1.7,1.75, // 1-10
256 1.7,1.57,1.53, 1.4, 1.3,1.30,1.44, 1.4, 1.4, 1.4, //11-20
257 1.4, 1.4,1.46, 1.4, 1.4,1.46,1.55, 1.5,1.38,1.48, //21-30
258 1.4, 1.4, 1.4,1.46, 1.4, 1.4, 1.4, 1.4, 1.4,1.45, //31-40
259 1.4, 1.4, 1.4, 1.4, 1.4, 1.4,1.45,1.48, 1.4,1.52, //41-50
260 1.46, 1.4, 1.4, 1.4, 1.4, 1.4, 1.4, 1.4, 1.4, 1.5, //51-60
261 1.4, 1.4, 1.4, 1.3, 1.3, 1.3, 1.3, 1.3, 1.3, 1.4, //61-70
262 1.3, 1.3, 1.3, 1.3, 1.3, 1.3, 1.3, 1.3,1.33,1.43, //71-80
263 1.3,1.32,1.34, 1.3, 1.3, 1.3, 1.3, 1.3, 1.3, 1.3, //81-90
264 1.3, 1.3};
265