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G4PreCompoundTriton.cc
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26 // $Id$
27 //
28 // -------------------------------------------------------------------
29 //
30 // GEANT4 Class file
31 //
32 //
33 // File name: G4PreCompoundTriton
34 //
35 // Author: V.Lara
36 //
37 // Modified:
38 // 21.08.2008 J. M. Quesada add choice of options
39 // 20.08.2010 V.Ivanchenko added G4Pow and G4PreCompoundParameters pointers
40 // use int Z and A and cleanup
41 //
42 
43 #include "G4PreCompoundTriton.hh"
44 #include "G4SystemOfUnits.hh"
45 #include "G4Triton.hh"
46 
48  : G4PreCompoundIon(G4Triton::Triton(), &theTritonCoulombBarrier)
49 {
50  ResidualA = GetRestA();
51  ResidualZ = GetRestZ();
52  theA = GetA();
53  theZ = GetZ();
54  ResidualAthrd = ResidualA13();
55  FragmentAthrd = ResidualAthrd;
56  FragmentA = theA + ResidualA;
57 }
58 
60 {}
61 
63 {
64  return G4double((N-3)*(P-2)*(N-2)*(P-1)*(N-1)*P)/6.0;
65 }
66 
68 {
69  return 243.0/G4double(A*A);
70 }
71 
73 {
74  G4double rj = 0.0;
75  if(nCharged >= 1 && (nParticles-nCharged) >= 2) {
76  G4double denominator =
77  G4double(nParticles*(nParticles-1)*(nParticles-2));
78  rj = G4double(3*nCharged*(nParticles-nCharged)*(nParticles-nCharged-1))
79  /denominator;
80  }
81  return rj;
82 }
83 
85 //J. M. Quesada (Dec 2007-June 2008): New inverse reaction cross sections
86 //OPT=0 Dostrovski's parameterization
87 //OPT=1,2 Chatterjee's paramaterization
88 //OPT=3,4 Kalbach's parameterization
89 //
91 {
92  ResidualA = GetRestA();
93  ResidualZ = GetRestZ();
94  theA = GetA();
95  theZ = GetZ();
96  ResidualAthrd = ResidualA13();
97  FragmentA = theA + ResidualA;
98  FragmentAthrd = g4pow->Z13(FragmentA);
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 TRITON CROSS SECTION OPTION !!" <<G4endl;
106  throw G4HadronicException(__FILE__, __LINE__, errOs.str());
107  return 0.;
108  }
109 }
110 
112 {
113  G4double C = 0.0;
114  G4int aZ = theZ + ResidualZ;
115  if (aZ >= 70)
116  {
117  C = 0.10;
118  }
119  else
120  {
121  C = ((((0.15417e-06*aZ) - 0.29875e-04)*aZ + 0.21071e-02)*aZ - 0.66612e-01)*aZ + 0.98375;
122  }
123 
124  return 1.0 + C/3.0;
125 }
126 
127 //
128 //********************* OPT=1,2 : Chatterjee's cross section *****************
129 //(fitting to cross section from Bechetti & Greenles OM potential)
130 
132 {
133  G4double Kc=K;
134 
135  // JMQ xsec is set constat above limit of validity
136  if (K > 50*MeV) { Kc=50*MeV; }
137 
138  G4double landa ,mu ,nu ,p , Ec,q,r,ji,xs;
139 
140  G4double p0 = -11.04;
141  G4double p1 = 619.1;
142  G4double p2 = -2147.;
143  G4double landa0 = -0.0426;
144  G4double landa1 = -10.33;
145  G4double mm0 = 601.9;
146  G4double mu1 = 0.37;
147  G4double nu0 = 583.0;
148  G4double nu1 = -546.2;
149  G4double nu2 = 1.718;
150  G4double delta=1.2;
151 
152  Ec = 1.44*theZ*ResidualZ/(1.5*ResidualAthrd+delta);
153  p = p0 + p1/Ec + p2/(Ec*Ec);
154  landa = landa0*ResidualA + landa1;
155 
156  G4double resmu1 = g4pow->powZ(ResidualA,mu1);
157  mu = mm0*resmu1;
158  nu = resmu1*(nu0 + nu1*Ec + nu2*(Ec*Ec));
159  q = landa - nu/(Ec*Ec) - 2*p*Ec;
160  r = mu + 2*nu/Ec + p*(Ec*Ec);
161 
162  ji=std::max(Kc,Ec);
163  if(Kc < Ec) { xs = p*Kc*Kc + q*Kc + r;}
164  else {xs = p*(Kc - ji)*(Kc - ji) + landa*Kc + mu + nu*(2 - Kc/ji)/ji ;}
165 
166  if (xs <0.0) {xs=0.0;}
167 
168  return xs;
169 }
170 
171 // *********** OPT=3,4 : Kalbach's cross sections (from PRECO code)*************
173 // ** t from o.m. of hafele, flynn et al
174 {
175  G4double landa, mu, nu, p , signor(1.),sig;
176  G4double ec,ecsq,xnulam,etest(0.),a;
177  G4double b,ecut,cut,ecut2,geom,elab;
178 
179  G4double flow = 1.e-18;
180  G4double spill= 1.e+18;
181 
182  G4double p0 = -21.45;
183  G4double p1 = 484.7;
184  G4double p2 = -1608.;
185  G4double landa0 = 0.0186;
186  G4double landa1 = -8.90;
187  G4double mm0 = 686.3;
188  G4double mu1 = 0.325;
189  G4double nu0 = 368.9;
190  G4double nu1 = -522.2;
191  G4double nu2 = -4.998;
192 
193  G4double ra=0.80;
194 
195  //JMQ 13/02/09 increase of reduced radius to lower the barrier
196  // ec = 1.44 * theZ * ResidualZ / (1.5*ResidualAthrd+ra);
197  ec = 1.44 * theZ * ResidualZ / (1.7*ResidualAthrd+ra);
198  ecsq = ec * ec;
199  p = p0 + p1/ec + p2/ecsq;
200  landa = landa0*ResidualA + landa1;
201  a = g4pow->powZ(ResidualA,mu1);
202  mu = mm0 * a;
203  nu = a* (nu0+nu1*ec+nu2*ecsq);
204  xnulam = nu / landa;
205  if (xnulam > spill) { xnulam=0.; }
206  if (xnulam >= flow) { etest = 1.2 *std::sqrt(xnulam); }
207 
208  a = -2.*p*ec + landa - nu/ecsq;
209  b = p*ecsq + mu + 2.*nu/ec;
210  ecut = 0.;
211  cut = a*a - 4.*p*b;
212  if (cut > 0.) { ecut = std::sqrt(cut); }
213  ecut = (ecut-a) / (p+p);
214  ecut2 = ecut;
215  //JMQ 290310 for avoiding unphysical increase below minimum (at ecut)
216  // ecut<0 means that there is no cut with energy axis, i.e. xs is set
217  // to 0 bellow minimum
218  // if (cut < 0.) ecut2 = ecut - 2.;
219  if (cut < 0.) { ecut2 = ecut; }
220  elab = K * FragmentA / G4double(ResidualA);
221  sig = 0.;
222 
223  if (elab <= ec) { //start for E<Ec
224  if (elab > ecut2) { sig = (p*elab*elab+a*elab+b) * signor; }
225  } //end for E<Ec
226  else { //start for E>Ec
227  sig = (landa*elab+mu+nu/elab) * signor;
228  geom = 0.;
229  if (xnulam < flow || elab < etest) { return sig; }
230  geom = std::sqrt(theA*K);
231  geom = 1.23*ResidualAthrd + ra + 4.573/geom;
232  geom = 31.416 * geom * geom;
233  sig = std::max(geom,sig);
234  } //end for E>Ec
235  return sig;
236 }