Geant4  10.00.p01
G4PreCompoundAlpha.cc
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26 // $Id: G4PreCompoundAlpha.cc 68028 2013-03-13 13:48:15Z gcosmo $
27 //
28 // -------------------------------------------------------------------
29 //
30 // GEANT4 Class file
31 //
32 //
33 // File name: G4PreCompoundAlpha
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 "G4PreCompoundAlpha.hh"
44 #include "G4SystemOfUnits.hh"
45 #include "G4Alpha.hh"
46 
48  : G4PreCompoundIon(G4Alpha::Alpha(), &theAlphaCoulombBarrier)
49 {
50  ResidualA = GetRestA();
51  ResidualZ = GetRestZ();
52  theA = GetA();
53  theZ = GetZ();
57 }
58 
60 {}
61 
63 {
64  return G4double((N-4)*(P-3)*(N-3)*(P-2)*(N-2)*(P-1)*(N-1)*P)/12.0;
65 }
66 
68 {
69  return 4096.0/G4double(A*A*A);
70 }
71 
73 {
74  G4double rj = 0.0;
75  if(nCharged >=2 && (nParticles-nCharged) >=2 ) {
76  G4double denominator =
77  G4double(nParticles*(nParticles-1)*(nParticles-2)*(nParticles-3));
78  rj = 6.0*nCharged*(nCharged-1)*(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();
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 Alpha 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 <= 30)
116  {
117  C = 0.10;
118  }
119  else if (aZ <= 50)
120  {
121  C = 0.1 - (aZ-30)*0.001;
122  }
123  else if (aZ < 70)
124  {
125  C = 0.08 - (aZ-50)*0.001;
126  }
127  else
128  {
129  C = 0.06;
130  }
131  return 1.0+C;
132 }
133 
134 //
135 //********************* OPT=1,2 : Chatterjee's cross section ********************
136 //(fitting to cross section from Bechetti & Greenles OM potential)
137 
139 {
140  G4double Kc=K;
141 
142  // JMQ xsec is set constant above limit of validity
143  if (K > 50*MeV) { Kc = 50*MeV; }
144 
145  G4double landa ,mu ,nu ,p , Ec,q,r,ji,xs;
146 
147  G4double p0 = 10.95;
148  G4double p1 = -85.2;
149  G4double p2 = 1146.;
150  G4double landa0 = 0.0643;
151  G4double landa1 = -13.96;
152  G4double mm0 = 781.2;
153  G4double mu1 = 0.29;
154  G4double nu0 = -304.7;
155  G4double nu1 = -470.0;
156  G4double nu2 = -8.580;
157  G4double delta=1.2;
158 
159  Ec = 1.44*theZ*ResidualZ/(1.5*ResidualAthrd+delta);
160  p = p0 + p1/Ec + p2/(Ec*Ec);
161  landa = landa0*ResidualA + landa1;
162  G4double resmu1 = g4pow->powZ(ResidualA,mu1);
163  mu = mm0*resmu1;
164  nu = resmu1*(nu0 + nu1*Ec + nu2*(Ec*Ec));
165  q = landa - nu/(Ec*Ec) - 2*p*Ec;
166  r = mu + 2*nu/Ec + p*(Ec*Ec);
167 
168  ji=std::max(Kc,Ec);
169  if(Kc < Ec) { xs = p*Kc*Kc + q*Kc + r;}
170  else {xs = p*(Kc - ji)*(Kc - ji) + landa*Kc + mu + nu*(2 - Kc/ji)/ji ;}
171 
172  if (xs <0.0) {xs=0.0;}
173 
174  return xs;
175 }
176 
177 // *********** OPT=3,4 : Kalbach's cross sections (from PRECO code)*************
179 // c ** alpha from huizenga and igo
180 {
181  G4double landa, mu, nu, p , signor(1.),sig;
182  G4double ec,ecsq,xnulam,etest(0.),a;
183  G4double b,ecut,cut,ecut2,geom,elab;
184 
185  G4double flow = 1.e-18;
186  G4double spill= 1.e+18;
187 
188  G4double p0 = 10.95;
189  G4double p1 = -85.2;
190  G4double p2 = 1146.;
191  G4double landa0 = 0.0643;
192  G4double landa1 = -13.96;
193  G4double mm0 = 781.2;
194  G4double mu1 = 0.29;
195  G4double nu0 = -304.7;
196  G4double nu1 = -470.0;
197  G4double nu2 = -8.580;
198 
199  G4double ra=1.20;
200 
201  //JMQ 13/02/09 increase of reduced radius to lower the barrier
202  // ec = 1.44 * theZ * ResidualZ / (1.5*ResidualAthrd+ra);
203  ec = 1.44 * theZ * ResidualZ / (1.7*ResidualAthrd+ra);
204  ecsq = ec * ec;
205  p = p0 + p1/ec + p2/ecsq;
206  landa = landa0*ResidualA + landa1;
207  a = g4pow->powZ(ResidualA,mu1);
208  mu = mm0 * a;
209  nu = a* (nu0+nu1*ec+nu2*ecsq);
210  xnulam = nu / landa;
211  if (xnulam > spill) { xnulam=0.; }
212  if (xnulam >= flow) { etest = 1.2 *std::sqrt(xnulam); }
213 
214  a = -2.*p*ec + landa - nu/ecsq;
215  b = p*ecsq + mu + 2.*nu/ec;
216  ecut = 0.;
217  cut = a*a - 4.*p*b;
218  if (cut > 0.) { ecut = std::sqrt(cut); }
219  ecut = (ecut-a) / (p+p);
220  ecut2 = ecut;
221  //JMQ 290310 for avoiding unphysical increase below minimum (at ecut)
222  // ecut<0 means that there is no cut with energy axis, i.e. xs is set
223  // to 0 bellow minimum
224  // if (cut < 0.) ecut2 = ecut - 2.;
225  if (cut < 0.) { ecut2 = ecut; }
226  elab = K * FragmentA / G4double(ResidualA);
227  sig = 0.;
228 
229  if (elab <= ec) { //start for E<Ec
230  if (elab > ecut2) { sig = (p*elab*elab+a*elab+b) * signor; }
231  } //end for E<Ec
232  else { //start for E>Ec
233  sig = (landa*elab+mu+nu/elab) * signor;
234  geom = 0.;
235  if (xnulam < flow || elab < etest) { return sig; }
236  geom = std::sqrt(theA*K);
237  geom = 1.23*ResidualAthrd + ra + 4.573/geom;
238  geom = 31.416 * geom * geom;
239  sig = std::max(geom,sig);
240  } //end for E>Ec
241  return sig;
242 }
virtual G4double CrossSection(G4double ekin)
static const double MeV
Definition: G4SIunits.hh:193
G4double GetOpt34(G4double K)
G4double ResidualA13() const
G4int GetA() const
G4double a
Definition: TRTMaterials.hh:39
G4double GetOpt0(G4double ekin)
int G4int
Definition: G4Types.hh:78
virtual G4double GetAlpha()
G4double Z13(G4int Z) const
Definition: G4Pow.hh:129
virtual G4double GetRj(G4int NumberParticles, G4int NumberCharged)
G4int GetRestZ() const
static const G4double A[nN]
T max(const T t1, const T t2)
brief Return the largest of the two arguments
virtual G4double FactorialFactor(G4int N, G4int P)
G4int GetRestA() const
#define G4endl
Definition: G4ios.hh:61
G4int GetZ() const
virtual G4double CoalescenceFactor(G4int A)
G4double powZ(G4int Z, G4double y) const
Definition: G4Pow.hh:258
double G4double
Definition: G4Types.hh:76
G4double GetOpt12(G4double K)