Geant4  10.01.p03
G4PreCompoundHe3.cc
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26 // $Id: G4PreCompoundHe3.cc 90591 2015-06-04 13:45:29Z gcosmo $
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28 // -------------------------------------------------------------------
29 //
30 // GEANT4 Class file
31 //
32 //
33 // File name: G4PreCompoundHe3
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 // 05.07.2013 J.M. Quesada FactorialFactor fixed
42 //
43 
44 #include "G4PreCompoundHe3.hh"
45 #include "G4SystemOfUnits.hh"
46 #include "G4He3.hh"
47 
49  : G4PreCompoundIon(G4He3::He3(), &theHe3CoulombBarrier)
50 {
51  ResidualA = GetRestA();
52  ResidualZ = GetRestZ();
53  theA = GetA();
54  theZ = GetZ();
58 }
59 
61 {}
62 
64 {
65  return G4double((N-3)*(P-2)*(N-2)*(P-1)*(N-1)*P)/12.0;
66 }
67 
69 {
70  return 243.0/G4double(A*A);
71 }
72 
74 {
75  G4double rj = 0.0;
76  if(nCharged >=2 && (nParticles-nCharged) >= 1) {
77  G4double denominator = G4double(nParticles*(nParticles-1)*(nParticles-2));
78  rj = G4double(3*nCharged*(nCharged-1)*(nParticles-nCharged))/denominator;
79  }
80  return rj;
81 }
82 
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 //
90 {
91  ResidualA = GetRestA();
92  ResidualZ = GetRestZ();
93  theA = GetA();
94  theZ = GetZ();
98 
99  if (OPTxs==0) { return GetOpt0( K); }
100  else if( OPTxs <= 2) { return GetOpt12( K); }
101  else { return GetOpt34( K); }
102 }
103 
105 {
106  G4double C = 0.0;
107  G4int aZ = theZ + ResidualZ;
108  if (aZ <= 30)
109  {
110  C = 0.10;
111  }
112  else if (aZ <= 50)
113  {
114  C = 0.1 - (aZ - 30)*0.001;
115  }
116  else if (aZ < 70)
117  {
118  C = 0.08 - (aZ - 50)*0.001;
119  }
120  else
121  {
122  C = 0.06;
123  }
124  return 1.0 + C*(4.0/3.0);
125 }
126 
127 //********************* OPT=1,2 : Chatterjee's cross section *****************
128 //(fitting to cross section from Bechetti & Greenles OM potential)
129 
131 {
132  G4double Kc = K;
133 
134  // JMQ xsec is set constat above limit of validity
135  if (K > 50*MeV) { Kc = 50*MeV; }
136 
137  G4double landa ,mu ,nu ,p , Ec,q,r,ji,xs;
138 
139  const G4double p0 = -3.06;
140  const G4double p1 = 278.5;
141  const G4double p2 = -1389.;
142  const G4double landa0 = -0.00535;
143  const G4double landa1 = -11.16;
144  const G4double mm0 = 555.5;
145  const G4double mu1 = 0.40;
146  const G4double nu0 = 687.4;
147  const G4double nu1 = -476.3;
148  const G4double nu2 = 0.509;
149  const G4double delta=1.2;
150 
151  Ec = 1.44*theZ*ResidualZ/(1.5*ResidualAthrd+delta);
152  p = p0 + p1/Ec + p2/(Ec*Ec);
153  landa = landa0*ResidualA + landa1;
154 
155  G4double resmu1 = g4pow->powZ(ResidualA,mu1);
156  mu = mm0*resmu1;
157  nu = resmu1*(nu0 + nu1*Ec + nu2*(Ec*Ec));
158  q = landa - nu/(Ec*Ec) - 2*p*Ec;
159  r = mu + 2*nu/Ec + p*(Ec*Ec);
160 
161  ji=std::max(Kc,Ec);
162  if(Kc < Ec) { xs = p*Kc*Kc + q*Kc + r;}
163  else {xs = p*(Kc - ji)*(Kc - ji) + landa*Kc + mu + nu*(2 - Kc/ji)/ji ;}
164 
165  xs = std::max(xs, 0.0);
166  return xs;
167 
168 }
169 
170 // *********** OPT=3,4 : Kalbach's cross sections (from PRECO code)*************
172 //c ** 3he from o.m. of gibson et al
173 {
174  const G4double flow = 1.e-18;
175  const G4double spill= 1.e+18;
176 
177  const G4double p0 = -2.88;
178  const G4double p1 = 205.6;
179  const G4double p2 = -1487.;
180  const G4double landa0 = 0.00459;
181  const G4double landa1 = -8.93;
182  const G4double mm0 = 611.2;
183  const G4double mu1 = 0.35;
184  const G4double nu0 = 473.8;
185  const G4double nu1 = -468.2;
186  const G4double nu2 = -2.225;
187 
188  const G4double ra = 0.80;
189  const G4double signor = 1.0;
190 
191  //JMQ 13/02/09 increase of reduced radius to lower the barrier
192  // ec = 1.44 * theZ * ResidualZ / (1.5*ResidualAthrd+ra);
193  G4double ec = 1.44 * theZ * ResidualZ / (1.7*ResidualAthrd+ra);
194  G4double ecsq = ec * ec;
195  G4double p = p0 + p1/ec + p2/ecsq;
196  G4double landa = landa0*ResidualA + landa1;
197  G4double a = g4pow->powZ(ResidualA,mu1);
198  G4double mu = mm0 * a;
199  G4double nu = a* (nu0+nu1*ec+nu2*ecsq);
200  G4double xnulam = nu / landa;
201  G4double etest = 0.0;
202  if (xnulam > spill) { xnulam=0.; }
203  else if (xnulam >= flow) { etest = 1.2 *std::sqrt(xnulam); }
204 
205  a = -2.*p*ec + landa - nu/ecsq;
206  G4double b = p*ecsq + mu + 2.*nu/ec;
207  G4double ecut = 0.;
208  G4double cut = a*a - 4.*p*b;
209  if (cut > 0.) { ecut = std::sqrt(cut); }
210  ecut = (ecut-a) / (2*p);
211 
212  //JMQ 290310 for avoiding unphysical increase below minimum (at ecut)
213  // ecut<0 means that there is no cut with energy axis, i.e. xs is set
214  // to 0 bellow minimum
215 
216  G4double elab = K * FragmentA / G4double(ResidualA);
217  G4double sig = 0.;
218 
219  if (elab <= ec) {
220  if (elab > ecut) { sig = std::max(0.0,(p*elab*elab+a*elab+b) * signor); }
221 
222  } else {
223  sig = (landa*elab+mu+nu/elab) * signor;
224  G4double geom = 0.;
225  if (xnulam >= flow && elab >= etest) {
226  geom = std::sqrt(theA*K);
227  geom = 1.23*ResidualAthrd + ra + 4.573/geom;
228  geom = 31.416 * geom * geom;
229  }
230  sig = std::max(geom,sig);
231  }
232  return sig;
233 }
static const double MeV
Definition: G4SIunits.hh:193
G4double GetOpt12(G4double K)
G4double ResidualA13() const
Definition: G4He3.hh:51
G4int GetA() const
const G4double nu1
G4double a
Definition: TRTMaterials.hh:39
G4double GetOpt0(G4double ekin)
int G4int
Definition: G4Types.hh:78
virtual G4double GetRj(G4int NumberParticles, G4int NumberCharged)
virtual ~G4PreCompoundHe3()
const G4double mm0
G4double Z13(G4int Z) const
Definition: G4Pow.hh:127
const G4double landa1
const G4double nu0
virtual G4double CoalescenceFactor(G4int A)
const G4double p2
const G4double p1
G4int GetRestZ() const
static const G4double A[nN]
const G4double mu1
virtual G4double GetAlpha()
G4double GetOpt34(G4double K)
const G4double p0
T max(const T t1, const T t2)
brief Return the largest of the two arguments
const G4double nu2
G4int GetRestA() const
G4int GetZ() const
G4double powZ(G4int Z, G4double y) const
Definition: G4Pow.hh:256
double G4double
Definition: G4Types.hh:76
virtual G4double CrossSection(G4double ekin)
const G4double landa0
virtual G4double FactorialFactor(G4int N, G4int P)