Geant4  10.02
G4NeutronInelasticCrossSection.cc
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25 //
26 // By JPW, working, but to be cleaned up. @@@
27 // 22 Dec 2006 - DHW added isotope dependence
28 // G.Folger, 25-Nov-2009: extend to 100TeV, using a constant above 20GeV
29 // 19 Aug 2011, V.Ivanchenko move to new design and make x-section per element
30 //
31 
33 #include "G4PhysicalConstants.hh"
34 #include "G4SystemOfUnits.hh"
35 #include "G4DynamicParticle.hh"
36 #include "G4HadTmpUtil.hh"
37 #include "G4NistManager.hh"
38 #include "G4Pow.hh"
39 
41  : G4VCrossSectionDataSet("Wellisch-Laidlaw"),
42  minEnergy(19.9*MeV), maxEnergy(19.9*GeV)
43 {}
44 
46 {}
47 
48 void
50 {
51  outFile << "G4NeutronInelasticCrossSection calculates the inelastic neutron\n"
52  << "scattering cross section for nuclei using the Wellisch-Laidlaw\n"
53  << "parameterization between 19.9 MeV and 19.9 GeV. Above 19.9 GeV\n"
54  << "the cross section is assumed to be constant.\n";
55 }
56 
57 G4bool
59  const G4DynamicParticle* part, G4int Z, const G4Material*)
60 {
61  G4double e = part->GetKineticEnergy();
62  return (1 < Z && e > minEnergy);
63 }
64 
67  G4int Z, const G4Material*)
68 {
69  G4int A = G4int(G4NistManager::Instance()->GetAtomicMassAmu(Z));
70  return GetCrossSection(aPart->GetKineticEnergy(), Z, A);
71 }
72 
73 G4double
75  G4int Z, G4int A)
76 {
77  if(anEnergy > maxEnergy) { anEnergy = maxEnergy; }
78  G4double cross_section = 0.0;
79  if(anEnergy < keV) { return cross_section; }
80 
81  G4Pow* g4pow = G4Pow::GetInstance();
82  G4double A13 = g4pow->Z13(A);
83 
84  G4double elog = std::log10(anEnergy/MeV);
85  G4int nOfNeutrons = A - Z;
86  G4double atomicNumber = G4double(A);
87  static const G4double p1=1.3773;
88  G4double p2 = 1. + 10./atomicNumber - 0.0006*atomicNumber;
89  G4double p3 = 0.6+ 13./atomicNumber - 0.0005*atomicNumber;
90  G4double p4 = 7.2449 - 0.018242*atomicNumber;
91  G4double p5 = 1.64 - 1.8/atomicNumber - 0.0005*atomicNumber;
92  G4double p6 = 1. + 200./atomicNumber + 0.02*atomicNumber;
93  G4double p7 = (atomicNumber-70.)*(atomicNumber-200.)/11000.;
94 
95  G4double logN = g4pow->logZ(nOfNeutrons);
96  G4double part1 = pi*p1*p1*logN;
97  G4double part2 = 1.+ A13 - p2*(1.-1./A13);
98 
99  G4double firstexp = -p4*(elog-p5);
100  G4double first = 1. + G4Exp(firstexp);
101  G4double corr = 1. + p3*(1.-1./first);
102 
103  G4double secondexp= -p6*(elog-p7);
104  G4double secondv = 1.+G4Exp(secondexp);
105  G4double corr2 = 1./secondv;
106 
107  G4double xsec = corr*corr2*part1*part2*10.*millibarn;
108  if(xsec < 0.0) { xsec = 0.0; }
109  return xsec;
110 }
static G4Pow * GetInstance()
Definition: G4Pow.cc:55
virtual void CrossSectionDescription(std::ostream &) const
static const double MeV
Definition: G4SIunits.hh:211
#define A13
G4double GetKineticEnergy() const
Definition: G4Pow.hh:56
G4double GetCrossSection(G4double kineticEnergy, G4int Z, G4int A)
virtual G4double GetElementCrossSection(const G4DynamicParticle *, G4int Z, const G4Material *)
int G4int
Definition: G4Types.hh:78
static G4NistManager * Instance()
G4double logZ(G4int Z) const
Definition: G4Pow.hh:166
G4double Z13(G4int Z) const
Definition: G4Pow.hh:127
double A(double temperature)
bool G4bool
Definition: G4Types.hh:79
static const double GeV
Definition: G4SIunits.hh:214
virtual G4bool IsElementApplicable(const G4DynamicParticle *aPart, G4int Z, const G4Material *)
G4double G4Exp(G4double initial_x)
Exponential Function double precision.
Definition: G4Exp.hh:183
static const double pi
Definition: G4SIunits.hh:74
static const double millibarn
Definition: G4SIunits.hh:105
static const double keV
Definition: G4SIunits.hh:213
double G4double
Definition: G4Types.hh:76