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G4PreCompoundProton.cc
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26 // $Id$
27 //
28 // -------------------------------------------------------------------
29 //
30 // GEANT4 Class file
31 //
32 //
33 // File name: G4PreCompoundProton
34 //
35 // Author: V.Lara
36 //
37 // Modified:
38 // 21.08.2008 J. M. Quesada added external choice of inverse cross section option
39 // 21.08.2008 J. M. Quesada added external choice for superimposed Coulomb
40 // barrier (if useSICB=true)
41 // 20.08.2010 V.Ivanchenko added G4Pow and G4PreCompoundParameters pointers
42 // use int Z and A and cleanup
43 //
44 
45 #include "G4PreCompoundProton.hh"
46 #include "G4PhysicalConstants.hh"
47 #include "G4SystemOfUnits.hh"
48 #include "G4Proton.hh"
49 
51  : G4PreCompoundNucleon(G4Proton::Proton(), &theProtonCoulombBarrier)
52 {
53  ResidualA = GetRestA();
54  ResidualZ = GetRestZ();
55  theA = GetA();
56  theZ = GetZ();
57  ResidualAthrd = ResidualA13();
58  FragmentAthrd = ResidualAthrd;
59  FragmentA = theA + ResidualA;
60 }
61 
63 {}
64 
66 {
67  G4double rj = 0.0;
68  if(nParticles > 0) {
69  rj = static_cast<G4double>(nCharged)/static_cast<G4double>(nParticles);
70  }
71  return rj;
72 }
73 
75 //J. M. Quesada (Dec 2007-June 2008): New inverse reaction cross sections
76 //OPT=0 Dostrovski's parameterization
77 //OPT=1 Chatterjee's paramaterization
78 //OPT=2,4 Wellisch's parametarization
79 //OPT=3 Kalbach's parameterization
80 //
82 {
83  ResidualA = GetRestA();
84  ResidualZ = GetRestZ();
85  theA = GetA();
86  theZ = GetZ();
87  ResidualAthrd = ResidualA13();
88  FragmentA = theA + ResidualA;
89  FragmentAthrd = g4pow->Z13(FragmentA);
90 
91  if (OPTxs==0) { return GetOpt0(K); }
92  else if( OPTxs==1) { return GetOpt1(K); }
93  else if( OPTxs==2|| OPTxs==4) { return GetOpt2(K); }
94  else if (OPTxs==3) { return GetOpt3(K); }
95  else{
96  std::ostringstream errOs;
97  errOs << "BAD PROTON CROSS SECTION OPTION !!" <<G4endl;
98  throw G4HadronicException(__FILE__, __LINE__, errOs.str());
99  return 0.;
100  }
101 }
102 
104 {
105  G4int aZ = ResidualZ;
106  G4double C = 0.0;
107  if (aZ >= 70)
108  {
109  C = 0.10;
110  }
111  else
112  {
113  C = ((((0.15417e-06*aZ) - 0.29875e-04)*aZ + 0.21071e-02)*aZ - 0.66612e-01)*aZ + 0.98375;
114  }
115  return 1.0 + C;
116 }
117 
119 {
120  return -GetCoulombBarrier();
121 }
122 
123 //********************* OPT=1 : Chatterjee's cross section *********************
124 //(fitting to cross section from Bechetti & Greenles OM potential)
125 
127 {
128  G4double Kc=K;
129 
130  // JMQ xsec is set constat above limit of validity
131  if (K > 50*MeV) { Kc = 50*MeV; }
132 
133  G4double landa, landa0, landa1, mu, mm0, mu1,nu, nu0, nu1, nu2,xs;
134  G4double p, p0, p1, p2,Ec,delta,q,r,ji;
135 
136  p0 = 15.72;
137  p1 = 9.65;
138  p2 = -449.0;
139  landa0 = 0.00437;
140  landa1 = -16.58;
141  mm0 = 244.7;
142  mu1 = 0.503;
143  nu0 = 273.1;
144  nu1 = -182.4;
145  nu2 = -1.872;
146  delta=0.;
147 
148  Ec = 1.44*theZ*ResidualZ/(1.5*ResidualAthrd+delta);
149  p = p0 + p1/Ec + p2/(Ec*Ec);
150  landa = landa0*ResidualA + landa1;
151 
152  G4double resmu1 = g4pow->powZ(ResidualA,mu1);
153  mu = mm0*resmu1;
154  nu = resmu1*(nu0 + nu1*Ec + nu2*(Ec*Ec));
155  q = landa - nu/(Ec*Ec) - 2*p*Ec;
156  r = mu + 2*nu/Ec + p*(Ec*Ec);
157 
158  ji=std::max(Kc,Ec);
159  if(Kc < Ec) { xs = p*Kc*Kc + q*Kc + r;}
160  else {xs = p*(Kc - ji)*(Kc - ji) + landa*Kc + mu + nu*(2 - Kc/ji)/ji ;}
161  if (xs <0.0) {xs=0.0;}
162 
163  return xs;
164 }
165 
166 //************* OPT=2 : Welisch's proton reaction cross section ***************
167 
169 {
170 
171  G4double eekin,ekin,ff1,ff2,ff3,r0,fac,fac1,fac2,b0,xine_th(0);
172 
173  // This is redundant when the Coulomb barrier is overimposed to all
174  // cross sections
175  // It should be kept when Coulomb barrier only imposed at OPTxs=2
176 
177  if(!useSICB && K<=theCoulombBarrier) { return 0.0; }
178 
179  eekin=K;
180  G4int rnneu=ResidualA-ResidualZ;
181  ekin=eekin/1000;
182  r0=1.36*1.e-15;
183  fac=pi*r0*r0;
184  b0=2.247-0.915*(1.-1./ResidualAthrd);
185  fac1=b0*(1.-1./ResidualAthrd);
186  fac2=1.;
187  if(rnneu > 1.5) { fac2 = g4pow->logZ(rnneu); }
188  xine_th= 1.e+31*fac*fac2*(1.+ResidualAthrd-fac1);
189  xine_th=(1.-0.15*std::exp(-ekin))*xine_th/(1.00-0.0007*ResidualA);
190  ff1=0.70-0.0020*ResidualA;
191  ff2=1.00+1/G4double(ResidualA);
192  ff3=0.8+18/G4double(ResidualA)-0.002*ResidualA;
193  fac=1.-(1./(1.+std::exp(-8.*ff1*(std::log10(ekin)+1.37*ff2))));
194  xine_th=xine_th*(1.+ff3*fac);
195  ff1=1.-1/G4double(ResidualA)-0.001*ResidualA;
196  ff2=1.17-2.7/G4double(ResidualA)-0.0014*ResidualA;
197  fac=-8.*ff1*(std::log10(ekin)+2.0*ff2);
198  fac=1./(1.+std::exp(fac));
199  xine_th=xine_th*fac;
200  if (xine_th < 0.0){
201  std::ostringstream errOs;
202  G4cout<<"WARNING: negative Wellisch cross section "<<G4endl;
203  errOs << "RESIDUAL: A=" << ResidualA << " Z=" << ResidualZ <<G4endl;
204  errOs <<" xsec("<<ekin<<" MeV) ="<<xine_th <<G4endl;
205  throw G4HadronicException(__FILE__, __LINE__, errOs.str());
206  }
207  return xine_th;
208 }
209 
210 // *********** OPT=3 : Kalbach's cross sections (from PRECO code)*************
212 {
213  // ** p from becchetti and greenlees (but modified with sub-barrier
214  // ** correction function and xp2 changed from -449)
215 
216  G4double landa, landa0, landa1, mu, mm0, mu1,nu, nu0, nu1, nu2;
217  G4double p, p0, p1, p2;
218  p0 = 15.72;
219  p1 = 9.65;
220  p2 = -300.;
221  landa0 = 0.00437;
222  landa1 = -16.58;
223  mm0 = 244.7;
224  mu1 = 0.503;
225  nu0 = 273.1;
226  nu1 = -182.4;
227  nu2 = -1.872;
228 
229  // parameters for proton cross section refinement
230  /*
231  G4double afit,bfit,a2,b2;
232  afit=-0.0785656;
233  bfit=5.10789;
234  a2= -0.00089076;
235  b2= 0.0231597;
236  */
237 
238  G4double ec,ecsq,xnulam,etest(0.),ra(0.),a,w,c,signor(1.),signor2,sig;
239  G4double b,ecut,cut,ecut2,geom,elab;
240 
241  G4double flow = 1.e-18;
242  G4double spill= 1.e+18;
243 
244  if (ResidualA <= 60) { signor = 0.92; }
245  else if (ResidualA < 100) { signor = 0.8 + ResidualA*0.002; }
246 
247  ec = 1.44 * theZ * ResidualZ / (1.5*ResidualAthrd+ra);
248  ecsq = ec * ec;
249  p = p0 + p1/ec + p2/ecsq;
250  landa = landa0*ResidualA + landa1;
251  a = g4pow->powZ(ResidualA,mu1);
252  mu = mm0 * a;
253  nu = a* (nu0+nu1*ec+nu2*ecsq);
254 
255  c =std::min(3.15,ec*0.5);
256  w = 0.7 * c / 3.15;
257 
258  xnulam = nu / landa;
259  if (xnulam > spill) { xnulam=0.; }
260  if (xnulam >= flow) { etest =std::sqrt(xnulam) + 7.; }
261 
262  a = -2.*p*ec + landa - nu/ecsq;
263  b = p*ecsq + mu + 2.*nu/ec;
264  ecut = 0.;
265  cut = a*a - 4.*p*b;
266  if (cut > 0.) { ecut = std::sqrt(cut); }
267  ecut = (ecut-a) / (p+p);
268  ecut2 = ecut;
269  //JMQ 290310 for avoiding unphysical increase below minimum (at ecut)
270  // ecut<0 means that there is no cut with energy axis, i.e. xs is set
271  // to 0 bellow minimum
272  // if (cut < 0.) ecut2 = ecut - 2.;
273  if (cut < 0.) { ecut2 = ecut; }
274  elab = K * FragmentA /G4double(ResidualA);
275  sig = 0.;
276  if (elab <= ec) { //start for E<Ec
277  if (elab > ecut2) { sig = (p*elab*elab+a*elab+b) * signor; }
278 
279  signor2 = (ec-elab-c) / w;
280  signor2 = 1. + std::exp(signor2);
281  sig = sig / signor2;
282  } //end for E<=Ec
283  else{ //start for E>Ec
284  sig = (landa*elab+mu+nu/elab) * signor;
285  geom = 0.;
286 
287  if (xnulam < flow || elab < etest)
288  {
289  if (sig <0.0) {sig=0.0;}
290  return sig;
291  }
292  geom = std::sqrt(theA*K);
293  geom = 1.23*ResidualAthrd + ra + 4.573/geom;
294  geom = 31.416 * geom * geom;
295  sig = std::max(geom,sig);
296 
297  } //end for E>Ec
298  return sig;
299 }