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NeutronPhysics.cc
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1 // $Id: $
3 // //
4 // File: NeutronPhysics.cc //
5 // Description: Neutron hadronic physics constructor for EICPhysicsList //
6 // //
7 // Author: Dennis H. Wright (SLAC) //
8 // Date: 3 July 2018 //
9 // //
11 
12 
13 #include "NeutronPhysics.hh"
14 
15 #include <Geant4/G4ProcessManager.hh>
16 #include <Geant4/G4NeutronInelasticProcess.hh>
17 #include <Geant4/G4HadronElasticProcess.hh>
18 #include <Geant4/G4HadronCaptureProcess.hh>
19 #include <Geant4/G4NeutronKiller.hh>
20 
21 #include <Geant4/G4CascadeInterface.hh>
22 #include <Geant4/G4TheoFSGenerator.hh>
23 #include <Geant4/G4FTFModel.hh>
24 #include <Geant4/G4ExcitedStringDecay.hh>
25 #include <Geant4/G4LundStringFragmentation.hh>
26 #include <Geant4/G4GeneratorPrecompoundInterface.hh>
27 #include <Geant4/G4ChipsElasticModel.hh>
28 #include <Geant4/G4NeutronRadCapture.hh>
29 
30 #include <Geant4/G4BGGNucleonInelasticXS.hh>
31 #include <Geant4/G4NeutronElasticXS.hh>
32 #include <Geant4/G4NeutronCaptureXS.hh>
33 
34 #include <Geant4/G4SystemOfUnits.hh>
35 
36 
37 NeutronPhysics::NeutronPhysics():
38  ftfp(nullptr),
39  stringModel(nullptr),
40  stringDecay(nullptr),
41  fragModel(nullptr),
42  preCompoundModel(nullptr)
43 {}
44 
45 
46 NeutronPhysics::~NeutronPhysics()
47 {
48  delete stringDecay;
49  delete stringModel;
50  delete fragModel;
51  delete preCompoundModel;
52 }
53 
54 
55 void NeutronPhysics::ConstructParticle()
56 {}
57 
58 
59 void NeutronPhysics::ConstructProcess()
60 {
61  // Low energy elastic model
62  G4ChipsElasticModel* elMod = new G4ChipsElasticModel();
63 
64  // Use Bertini cascade for low energies
65  G4CascadeInterface* loInelModel = new G4CascadeInterface;
66  loInelModel->SetMinEnergy(0.0);
67  loInelModel->SetMaxEnergy(12.0*GeV);
68 
69  // Capture model
70  G4NeutronRadCapture* capModel = new G4NeutronRadCapture();
71 
72  // Use FTFP for high energies ==>> eventually replace this with new class FTFPInterface
73  ftfp = new G4TheoFSGenerator("FTFP");
74  stringModel = new G4FTFModel;
75  stringDecay =
76  new G4ExcitedStringDecay(fragModel = new G4LundStringFragmentation);
77  stringModel->SetFragmentationModel(stringDecay);
78  preCompoundModel = new G4GeneratorPrecompoundInterface();
79 
80  ftfp->SetHighEnergyGenerator(stringModel);
81  ftfp->SetTransport(preCompoundModel);
82  ftfp->SetMinEnergy(5*GeV);
83  ftfp->SetMaxEnergy(100*TeV);
84 
85  // Cross section sets
86  G4BGGNucleonInelasticXS* inelCS = new G4BGGNucleonInelasticXS(G4Neutron::Neutron() );
87  G4NeutronElasticXS* elCS = new G4NeutronElasticXS;
88  G4NeutronCaptureXS* capCS = new G4NeutronCaptureXS;
89 
90  G4ProcessManager* procMan = G4Neutron::Neutron()->GetProcessManager();
91 
92  // Elastic process
93  G4HadronElasticProcess* nProcEl = new G4HadronElasticProcess;
94  nProcEl->RegisterMe(elMod);
95  nProcEl->AddDataSet(elCS);
96  procMan->AddDiscreteProcess(nProcEl);
97 
98  // Inelastic process
99  G4NeutronInelasticProcess* nProcInel = new G4NeutronInelasticProcess;
100  nProcInel->RegisterMe(loInelModel);
101  nProcInel->RegisterMe(ftfp);
102  nProcInel->AddDataSet(inelCS);
103  procMan->AddDiscreteProcess(nProcInel);
104 
105  // Capture process
106  G4HadronCaptureProcess* nProcCap = new G4HadronCaptureProcess("nCapture");
107  nProcCap->RegisterMe(capModel);
108  nProcCap->AddDataSet(capCS);
109  procMan->AddDiscreteProcess(nProcCap);
110 
111  // Neutron cut (kill neutrons that live too long or have too little energy)
112  G4NeutronKiller* nKiller = new G4NeutronKiller();
113  nKiller->SetKinEnergyLimit(0.0*MeV);
114  nKiller->SetTimeLimit(10.*microsecond);
115  procMan->AddDiscreteProcess(nKiller);
116 
117 }
118 
119