Geant4  10.00.p01
G4AlphaEvaporationProbability.cc
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26 // $Id: G4AlphaEvaporationProbability.cc 67983 2013-03-13 10:42:03Z gcosmo $
27 //
28 // J.M. Quesada (August2008). Based on:
29 //
30 // Hadronic Process: Nuclear De-excitations
31 // by V. Lara (Oct 1998)
32 //
33 // Modified:
34 // 03-09-2008 J.M. Quesada for external choice of inverse cross section option
35 // 17-11-2010 V.Ivanchenko integer Z and A
36 
38 #include "G4SystemOfUnits.hh"
39 
41  G4EvaporationProbability(4,2,1,&theCoulombBarrier) // A,Z,Gamma,&theCoumlombBarrier
42 {
45 }
46 
48 {}
49 
51  { return 1.0 + CCoeficient(fragment.GetZ_asInt()-GetZ());}
52 
54  { return 0.0; }
55 
57 {
58  // Data comes from
59  // Dostrovsky, Fraenkel and Friedlander
60  // Physical Review, vol 116, num. 3 1959
61  //
62  // const G4int size = 5;
63  // G4double Zlist[5] = { 10.0, 20.0, 30.0, 50.0, 70.0};
64  // G4double Calpha[5] = { 0.10, 0.10, 0.10, 0.08, 0.06};
65  G4double C = 0.0;
66 
67  if (aZ <= 30)
68  {
69  C = 0.10;
70  }
71  else if (aZ <= 50)
72  {
73  C = 0.1 - (aZ-30)*0.001;
74  }
75  else if (aZ < 70)
76  {
77  C = 0.08 - (aZ-50)*0.001;
78  }
79  else
80  {
81  C = 0.06;
82  }
83  return C;
84 }
85 
87 //J. M. Quesada (Dec 2007-June 2008): New inverse reaction cross sections
88 //OPT=0 Dostrovski's parameterization
89 //OPT=1,2 Chatterjee's paramaterization
90 //OPT=3,4 Kalbach's parameterization
91 //
92 G4double
94 {
95  theA=GetA();
96  theZ=GetZ();
97  ResidualA=fragment.GetA_asInt()-theA;
98  ResidualZ=fragment.GetZ_asInt()-theZ;
99 
101  FragmentA=fragment.GetA_asInt();
103 
104  if (OPTxs==0) {std::ostringstream errOs;
105  errOs << "We should'n be here (OPT =0) at evaporation cross section calculation (Alpha's)!!"
106  <<G4endl;
107  throw G4HadronicException(__FILE__, __LINE__, errOs.str());
108  return 0.;}
109 
110  if( OPTxs==1 || OPTxs==2) return G4AlphaEvaporationProbability::GetOpt12( K);
111  else if (OPTxs==3 || OPTxs==4) return G4AlphaEvaporationProbability::GetOpt34( K);
112  else{
113  std::ostringstream errOs;
114  errOs << "BAD Alpha CROSS SECTION OPTION AT EVAPORATION!!" <<G4endl;
115  throw G4HadronicException(__FILE__, __LINE__, errOs.str());
116  return 0.;
117  }
118 }
119 
120 //
121 //********************* OPT=1,2 : Chatterjee's cross section ********************
122 //(fitting to cross section from Bechetti & Greenles OM potential)
123 
125 {
126  G4double Kc=K;
127 
128  // JMQ xsec is set constant above limit of validity
129  if (K > 50*MeV) { Kc = 50*MeV; }
130 
131  G4double landa ,mu ,nu ,p , Ec,q,r,ji,xs;
132 
133  G4double p0 = 10.95;
134  G4double p1 = -85.2;
135  G4double p2 = 1146.;
136  G4double landa0 = 0.0643;
137  G4double landa1 = -13.96;
138  G4double mum0 = 781.2;
139  G4double mu1 = 0.29;
140  G4double nu0 = -304.7;
141  G4double nu1 = -470.0;
142  G4double nu2 = -8.580;
143  G4double delta=1.2;
144 
145  Ec = 1.44*theZ*ResidualZ/(1.5*ResidualAthrd+delta);
146  p = p0 + p1/Ec + p2/(Ec*Ec);
147  landa = landa0*ResidualA + landa1;
148  G4double resmu1 = fG4pow->powZ(ResidualA,mu1);
149  mu = mum0*resmu1;
150  nu = resmu1*(nu0 + nu1*Ec + nu2*(Ec*Ec));
151  q = landa - nu/(Ec*Ec) - 2*p*Ec;
152  r = mu + 2*nu/Ec + p*(Ec*Ec);
153 
154  ji=std::max(Kc,Ec);
155  if(Kc < Ec) { xs = p*Kc*Kc + q*Kc + r;}
156  else {xs = p*(Kc - ji)*(Kc - ji) + landa*Kc + mu + nu*(2 - Kc/ji)/ji ;}
157 
158  if (xs <0.0) {xs=0.0;}
159 
160  return xs;
161 }
162 
163 // *********** OPT=3,4 : Kalbach's cross sections (from PRECO code)*************
165 // c ** alpha from huizenga and igo
166 {
167  G4double landa, mu, nu, p , signor(1.),sig;
168  G4double ec,ecsq,xnulam,etest(0.),a;
169  G4double b,ecut,cut,ecut2,geom,elab;
170 
171  G4double flow = 1.e-18;
172  G4double spill= 1.e+18;
173 
174  G4double p0 = 10.95;
175  G4double p1 = -85.2;
176  G4double p2 = 1146.;
177  G4double landa0 = 0.0643;
178  G4double landa1 = -13.96;
179  G4double mum0 = 781.2;
180  G4double mu1 = 0.29;
181  G4double nu0 = -304.7;
182  G4double nu1 = -470.0;
183  G4double nu2 = -8.580;
184 
185  G4double ra=1.20;
186 
187  //JMQ 13/02/09 increase of reduced radius to lower the barrier
188  // ec = 1.44 * theZ * ResidualZ / (1.5*ResidualAthrd+ra);
189  ec = 1.44 * theZ * ResidualZ / (1.7*ResidualAthrd+ra);
190  ecsq = ec * ec;
191  p = p0 + p1/ec + p2/ecsq;
192  landa = landa0*ResidualA + landa1;
193  a = fG4pow->powZ(ResidualA,mu1);
194  mu = mum0 * a;
195  nu = a* (nu0+nu1*ec+nu2*ecsq);
196  xnulam = nu / landa;
197  if (xnulam > spill) { xnulam=0.; }
198  if (xnulam >= flow) { etest = 1.2 *std::sqrt(xnulam); }
199 
200  a = -2.*p*ec + landa - nu/ecsq;
201  b = p*ecsq + mu + 2.*nu/ec;
202  ecut = 0.;
203  cut = a*a - 4.*p*b;
204  if (cut > 0.) { ecut = std::sqrt(cut); }
205  ecut = (ecut-a) / (p+p);
206  ecut2 = ecut;
207  //JMQ 290310 for avoiding unphysical increase below minimum (at ecut)
208  // ecut<0 means that there is no cut with energy axis, i.e. xs is set
209  // to 0 bellow minimum
210  // if (cut < 0.) ecut2 = ecut - 2.;
211  if (cut < 0.) { ecut2 = ecut; }
212  elab = K * FragmentA / G4double(ResidualA);
213  sig = 0.;
214 
215  if (elab <= ec) { //start for E<Ec
216  if (elab > ecut2) { sig = (p*elab*elab+a*elab+b) * signor; }
217  } //end for E<Ec
218  else { //start for E>Ec
219  sig = (landa*elab+mu+nu/elab) * signor;
220  geom = 0.;
221  if (xnulam < flow || elab < etest) { return sig; }
222  geom = std::sqrt(theA*K);
223  geom = 1.23*ResidualAthrd + ra + 4.573/geom;
224  geom = 31.416 * geom * geom;
225  sig = std::max(geom,sig);
226  } //end for E>Ec
227  return sig;
228 }
229 
static const double MeV
Definition: G4SIunits.hh:193
virtual G4double CalcBetaParam(const G4Fragment &fragment)
G4double a
Definition: TRTMaterials.hh:39
int G4int
Definition: G4Types.hh:78
G4double Z13(G4int Z) const
Definition: G4Pow.hh:129
G4int GetA_asInt() const
Definition: G4Fragment.hh:238
virtual G4double CrossSection(const G4Fragment &fragment, G4double K)
virtual G4double CalcAlphaParam(const G4Fragment &fragment)
T max(const T t1, const T t2)
brief Return the largest of the two arguments
G4int GetZ_asInt() const
Definition: G4Fragment.hh:243
#define G4endl
Definition: G4ios.hh:61
G4double powZ(G4int Z, G4double y) const
Definition: G4Pow.hh:258
double G4double
Definition: G4Types.hh:76