ECCE @ EIC Software
 All Classes Namespaces Files Functions Variables Typedefs Enumerations Enumerator Friends Macros Groups Pages
G4NeutronInelasticCrossSection.cc
Go to the documentation of this file. Or view the newest version in sPHENIX GitHub for file G4NeutronInelasticCrossSection.cc
1 //
2 // ********************************************************************
3 // * License and Disclaimer *
4 // * *
5 // * The Geant4 software is copyright of the Copyright Holders of *
6 // * the Geant4 Collaboration. It is provided under the terms and *
7 // * conditions of the Geant4 Software License, included in the file *
8 // * LICENSE and available at http://cern.ch/geant4/license . These *
9 // * include a list of copyright holders. *
10 // * *
11 // * Neither the authors of this software system, nor their employing *
12 // * institutes,nor the agencies providing financial support for this *
13 // * work make any representation or warranty, express or implied, *
14 // * regarding this software system or assume any liability for its *
15 // * use. Please see the license in the file LICENSE and URL above *
16 // * for the full disclaimer and the limitation of liability. *
17 // * *
18 // * This code implementation is the result of the scientific and *
19 // * technical work of the GEANT4 collaboration. *
20 // * By using, copying, modifying or distributing the software (or *
21 // * any work based on the software) you agree to acknowledge its *
22 // * use in resulting scientific publications, and indicate your *
23 // * acceptance of all terms of the Geant4 Software license. *
24 // ********************************************************************
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 }