source: trunk/source/processes/hadronic/models/pre_equilibrium/exciton_model/src/G4PreCompoundHe3.cc @ 1315

Last change on this file since 1315 was 1315, checked in by garnier, 14 years ago

update geant4-09-04-beta-cand-01 interfaces-V09-03-09 vis-V09-03-08
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27// $Id: G4PreCompoundHe3.cc,v 1.6 2010/04/09 14:06:17 vnivanch Exp $
28// GEANT4 tag $Name: geant4-09-04-beta-cand-01 $
29//
30// -------------------------------------------------------------------
31//
32// GEANT4 Class file
33//
34//
35// File name:     G4PreCompoundHe3
36//
37// Author:         V.Lara
38//
39// Modified: 
40// 21.08.2008 J. M. Quesada add choice of options 
41//
42 
43#include "G4PreCompoundHe3.hh"
44
45G4ReactionProduct * G4PreCompoundHe3::GetReactionProduct() const
46{
47  G4ReactionProduct * theReactionProduct =
48    new G4ReactionProduct(G4He3::He3Definition());
49  theReactionProduct->SetMomentum(GetMomentum().vect());
50  theReactionProduct->SetTotalEnergy(GetMomentum().e());
51#ifdef PRECOMPOUND_TEST
52  theReactionProduct->SetCreatorModel("G4PrecompoundModel");
53#endif
54  return theReactionProduct;
55}   
56
57G4double G4PreCompoundHe3::FactorialFactor(const G4double N, const G4double P)
58{
59  return 
60      (N-3.0)*(P-2.0)*(
61                       (((N-2.0)*(P-1.0))/2.0) *(
62                                                 (((N-1.0)*P)/3.0) 
63                                                 )
64                       );
65}
66 
67G4double G4PreCompoundHe3::CoalescenceFactor(const G4double A)
68{
69  return 243.0/(A*A);
70}   
71
72G4double G4PreCompoundHe3::GetRj(const G4int NumberParticles, const G4int NumberCharged)
73{
74  G4double rj = 0.0;
75  G4double denominator = NumberParticles*(NumberParticles-1)*(NumberParticles-2);
76  if(NumberCharged >=2 && (NumberParticles-NumberCharged) >= 1) {
77    rj = 3.0*static_cast<G4double>(NumberCharged*(NumberCharged-1)*(NumberParticles-NumberCharged))
78      / static_cast<G4double>(denominator); 
79  }
80  return rj;
81}
82
83////////////////////////////////////////////////////////////////////////////////////
84//J. M. Quesada (Dec 2007-June 2008): New inverse reaction cross sections
85//OPT=0 Dostrovski's parameterization
86//OPT=1,2 Chatterjee's paramaterization
87//OPT=3,4 Kalbach's parameterization
88//
89G4double G4PreCompoundHe3::CrossSection(const  G4double K)
90{
91  ResidualA=GetRestA();
92  ResidualZ=GetRestZ(); 
93  theA=GetA();
94  theZ=GetZ();
95  ResidualAthrd=std::pow(ResidualA,0.33333);
96  FragmentA=GetA()+GetRestA();
97  FragmentAthrd=std::pow(FragmentA,0.33333);
98
99
100  if (OPTxs==0) return GetOpt0( K);
101  else if( OPTxs==1 || OPTxs==2) return GetOpt12( K);
102  else if (OPTxs==3 || OPTxs==4)  return GetOpt34( K);
103  else{
104    std::ostringstream errOs;
105    errOs << "BAD He3 CROSS SECTION OPTION !!"  <<G4endl;
106    throw G4HadronicException(__FILE__, __LINE__, errOs.str());
107    return 0.;
108  }
109}
110
111// *********************** OPT=0 : Dostrovski's cross section  *****************************
112
113G4double G4PreCompoundHe3::GetOpt0(const  G4double K)
114{
115  const G4double r0 = G4PreCompoundParameters::GetAddress()->Getr0();
116  // cross section is now given in mb (r0 is in mm) for the sake of consistency
117  //with the rest of the options
118  return 1.e+25*pi*(r0*ResidualAthrd)*(r0*ResidualAthrd)*GetAlpha()*(1.+GetBeta()/K);
119}
120//
121//----------------
122//
123G4double G4PreCompoundHe3::GetAlpha()
124{
125  G4double C = 0.0;
126  G4double aZ = GetZ() + GetRestZ();
127  if (aZ <= 30) 
128    {
129      C = 0.10;
130    }
131  else if (aZ <= 50) 
132    {
133      C = 0.1 + -((aZ-50.)/20.)*0.02;
134    } 
135  else if (aZ < 70) 
136    {
137      C = 0.08 + -((aZ-70.)/20.)*0.02;
138    }
139  else 
140    {
141      C = 0.06;
142    }
143  return 1.0 + C*(4.0/3.0);
144}
145//
146//--------------------
147//
148G4double G4PreCompoundHe3::GetBeta() 
149{
150  return -GetCoulombBarrier();
151}
152//
153//********************* OPT=1,2 : Chatterjee's cross section ************************
154//(fitting to cross section from Bechetti & Greenles OM potential)
155
156G4double G4PreCompoundHe3::GetOpt12(const  G4double K)
157{
158
159  G4double Kc=K;
160
161  // JMQ xsec is set constat above limit of validity
162  if (K>50) Kc=50;
163
164  G4double landa ,mu ,nu ,p , Ec,q,r,ji,xs;
165
166  G4double      p0 = -3.06;
167  G4double     p1 = 278.5;
168  G4double     p2 = -1389.;
169  G4double     landa0 = -0.00535;
170  G4double     landa1 = -11.16;
171  G4double     mu0 = 555.5;
172  G4double     mu1 = 0.40;
173  G4double     nu0 = 687.4;
174  G4double     nu1 = -476.3;
175  G4double     nu2 = 0.509;   
176  G4double     delta=1.2;             
177
178  Ec = 1.44*theZ*ResidualZ/(1.5*ResidualAthrd+delta);
179  p = p0 + p1/Ec + p2/(Ec*Ec);
180  landa = landa0*ResidualA + landa1;
181  mu = mu0*std::pow(ResidualA,mu1);
182  nu = std::pow(ResidualA,mu1)*(nu0 + nu1*Ec + nu2*(Ec*Ec));
183  q = landa - nu/(Ec*Ec) - 2*p*Ec;
184  r = mu + 2*nu/Ec + p*(Ec*Ec);
185 
186  ji=std::max(Kc,Ec);
187  if(Kc < Ec) { xs = p*Kc*Kc + q*Kc + r;}
188  else {xs = p*(Kc - ji)*(Kc - ji) + landa*Kc + mu + nu*(2 - Kc/ji)/ji ;}
189 
190  if (xs <0.0) {xs=0.0;}
191             
192  return xs;
193
194}
195
196// *********** OPT=3,4 : Kalbach's cross sections (from PRECO code)*************
197G4double G4PreCompoundHe3::GetOpt34(const  G4double K)
198//c     ** 3he from o.m. of gibson et al
199{
200
201  G4double landa, mu, nu, p , signor(1.),sig;
202  G4double ec,ecsq,xnulam,etest(0.),a; 
203  G4double b,ecut,cut,ecut2,geom,elab;
204
205
206  G4double     flow = 1.e-18;
207  G4double     spill= 1.e+18;
208
209
210  G4double     p0 = -2.88;
211  G4double     p1 = 205.6;
212  G4double     p2 = -1487.;
213  G4double     landa0 = 0.00459;
214  G4double     landa1 = -8.93;
215  G4double     mu0 = 611.2;
216  G4double     mu1 = 0.35;
217  G4double     nu0 = 473.8;
218  G4double     nu1 = -468.2;
219  G4double     nu2 = -2.225;     
220 
221  G4double      ra=0.80;
222       
223  //JMQ 13/02/09 increase of reduced radius to lower the barrier
224  // ec = 1.44 * theZ * ResidualZ / (1.5*ResidualAthrd+ra);
225  ec = 1.44 * theZ * ResidualZ / (1.7*ResidualAthrd+ra);
226  ecsq = ec * ec;
227  p = p0 + p1/ec + p2/ecsq;
228  landa = landa0*ResidualA + landa1;
229  a = std::pow(ResidualA,mu1);
230  mu = mu0 * a;
231  nu = a* (nu0+nu1*ec+nu2*ecsq); 
232  xnulam = nu / landa;
233  if (xnulam > spill) xnulam=0.;
234  if (xnulam >= flow) etest = 1.2 *std::sqrt(xnulam);
235 
236  a = -2.*p*ec + landa - nu/ecsq;
237  b = p*ecsq + mu + 2.*nu/ec;
238  ecut = 0.;
239  cut = a*a - 4.*p*b;
240  if (cut > 0.) ecut = std::sqrt(cut);
241  ecut = (ecut-a) / (p+p);
242  ecut2 = ecut;
243//JMQ 290310 for avoiding unphysical increase below minimum (at ecut)
244//ecut<0 means that there is no cut with energy axis, i.e. xs is set to 0 bellow minimum
245//  if (cut < 0.) ecut2 = ecut - 2.;
246  if (cut < 0.) ecut2 = ecut;
247  elab = K * FragmentA / ResidualA;
248  sig = 0.;
249 
250  if (elab <= ec) { //start for E<Ec
251    if (elab > ecut2)  sig = (p*elab*elab+a*elab+b) * signor;
252  }           //end for E<Ec
253  else {           //start for E>Ec
254    sig = (landa*elab+mu+nu/elab) * signor;
255    geom = 0.;
256    if (xnulam < flow || elab < etest) return sig;
257    geom = std::sqrt(theA*K);
258    geom = 1.23*ResidualAthrd + ra + 4.573/geom;
259    geom = 31.416 * geom * geom;
260    sig = std::max(geom,sig);
261  }           //end for E>Ec
262  return sig;
263 
264}
265
266//   ************************** end of cross sections *******************************
267
268
269
270
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