source: trunk/source/processes/electromagnetic/lowenergy/src/G4LowEnergyRayleigh.cc

Last change on this file was 1347, checked in by garnier, 15 years ago

geant4 tag 9.4
File size: 8.3 KB
RevLine 
[819]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 *
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12// * institutes,nor the agencies providing financial support for this *
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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// --------------------------------------------------------------------
27//
[1192]28// $Id: G4LowEnergyRayleigh.cc,v 1.40 2009/06/11 15:47:08 mantero Exp $
[1347]29// GEANT4 tag $Name: geant4-09-04-ref-00 $
[819]30//
31// Author: A. Forti
32// Maria Grazia Pia (Maria.Grazia.Pia@cern.ch)
33//
34// History:
35// --------
36// Added Livermore data table construction methods A. Forti
37// Added BuildMeanFreePath A. Forti
38// Added PostStepDoIt A. Forti
39// Added SelectRandomAtom A. Forti
40// Added map of the elements A.Forti
41// 24.04.01 V.Ivanchenko remove RogueWave
42// 11.08.2001 MGP - Major revision according to a design iteration
43// 06.10.2001 MGP - Added strategy to test range for secondary generation
44// 05.06.2002 F.Longo and G.Depaola - bug fixed in angular distribution
45// 20.10.2002 G. Depaola - Change sampling method of theta
46// 22.01.2003 V.Ivanchenko - Cut per region
47// 24.04.2003 V.Ivanchenko - Cut per region mfpt
48//
49// --------------------------------------------------------------------
50
51#include "G4LowEnergyRayleigh.hh"
52#include "Randomize.hh"
53#include "G4ParticleDefinition.hh"
54#include "G4Track.hh"
55#include "G4Step.hh"
56#include "G4ForceCondition.hh"
57#include "G4Gamma.hh"
58#include "G4Electron.hh"
59#include "G4DynamicParticle.hh"
60#include "G4VParticleChange.hh"
61#include "G4ThreeVector.hh"
62#include "G4VCrossSectionHandler.hh"
63#include "G4CrossSectionHandler.hh"
64#include "G4VEMDataSet.hh"
65#include "G4CompositeEMDataSet.hh"
66#include "G4VDataSetAlgorithm.hh"
67#include "G4LogLogInterpolation.hh"
68
69#include "G4MaterialCutsCouple.hh"
70
71G4LowEnergyRayleigh::G4LowEnergyRayleigh(const G4String& processName)
72 : G4VDiscreteProcess(processName),
73 lowEnergyLimit(250*eV),
74 highEnergyLimit(100*GeV),
75 intrinsicLowEnergyLimit(10*eV),
76 intrinsicHighEnergyLimit(100*GeV)
77{
78 if (lowEnergyLimit < intrinsicLowEnergyLimit ||
79 highEnergyLimit > intrinsicHighEnergyLimit)
80 {
81 G4Exception("G4LowEnergyRayleigh::G4LowEnergyRayleigh - energy limit outside intrinsic process validity range");
82 }
83
84 crossSectionHandler = new G4CrossSectionHandler();
85
86 G4VDataSetAlgorithm* ffInterpolation = new G4LogLogInterpolation;
87 G4String formFactorFile = "rayl/re-ff-";
88 formFactorData = new G4CompositeEMDataSet(ffInterpolation,1.,1.);
89 formFactorData->LoadData(formFactorFile);
90
91 meanFreePathTable = 0;
92
93 if (verboseLevel > 0)
94 {
95 G4cout << GetProcessName() << " is created " << G4endl
96 << "Energy range: "
97 << lowEnergyLimit / keV << " keV - "
98 << highEnergyLimit / GeV << " GeV"
99 << G4endl;
100 }
[1055]101
102 G4cout << G4endl;
103 G4cout << "*******************************************************************************" << G4endl;
104 G4cout << "*******************************************************************************" << G4endl;
105 G4cout << " The class G4LowEnergyRayleigh is NOT SUPPORTED ANYMORE. " << G4endl;
106 G4cout << " It will be REMOVED with the next major release of Geant4. " << G4endl;
107 G4cout << " Please consult: https://twiki.cern.ch/twiki/bin/view/Geant4/LoweProcesses" << G4endl;
108 G4cout << "*******************************************************************************" << G4endl;
109 G4cout << "*******************************************************************************" << G4endl;
110 G4cout << G4endl;
[819]111}
112
113G4LowEnergyRayleigh::~G4LowEnergyRayleigh()
114{
115 delete meanFreePathTable;
116 delete crossSectionHandler;
117 delete formFactorData;
118}
119
120void G4LowEnergyRayleigh::BuildPhysicsTable(const G4ParticleDefinition& )
121{
122
123 crossSectionHandler->Clear();
124 G4String crossSectionFile = "rayl/re-cs-";
125 crossSectionHandler->LoadData(crossSectionFile);
126
127 delete meanFreePathTable;
128 meanFreePathTable = crossSectionHandler->BuildMeanFreePathForMaterials();
129}
130
131G4VParticleChange* G4LowEnergyRayleigh::PostStepDoIt(const G4Track& aTrack,
132 const G4Step& aStep)
133{
134
135 aParticleChange.Initialize(aTrack);
136
137 const G4DynamicParticle* incidentPhoton = aTrack.GetDynamicParticle();
138 G4double photonEnergy0 = incidentPhoton->GetKineticEnergy();
139
140 if (photonEnergy0 <= lowEnergyLimit)
141 {
142 aParticleChange.ProposeTrackStatus(fStopAndKill);
143 aParticleChange.ProposeEnergy(0.);
144 aParticleChange.ProposeLocalEnergyDeposit(photonEnergy0);
145 return G4VDiscreteProcess::PostStepDoIt(aTrack,aStep);
146 }
147
148 // G4double e0m = photonEnergy0 / electron_mass_c2 ;
149 G4ParticleMomentum photonDirection0 = incidentPhoton->GetMomentumDirection();
150
151 // Select randomly one element in the current material
152 const G4MaterialCutsCouple* couple = aTrack.GetMaterialCutsCouple();
153 G4int Z = crossSectionHandler->SelectRandomAtom(couple,photonEnergy0);
154
155 // Sample the angle of the scattered photon
156
157 G4double wlPhoton = h_Planck*c_light/photonEnergy0;
158
159 G4double gReject,x,dataFormFactor;
160 G4double randomFormFactor;
161 G4double cosTheta;
162 G4double sinTheta;
163 G4double fcostheta;
164
165 do
166 {
167 do
168 {
169 cosTheta = 2. * G4UniformRand() - 1.;
170 fcostheta = ( 1. + cosTheta*cosTheta)/2.;
171 } while (fcostheta < G4UniformRand());
172
173 G4double sinThetaHalf = std::sqrt((1. - cosTheta) / 2.);
174 x = sinThetaHalf / (wlPhoton/cm);
175 if (x > 1.e+005)
176 dataFormFactor = formFactorData->FindValue(x,Z-1);
177 else
178 dataFormFactor = formFactorData->FindValue(0.,Z-1);
179 randomFormFactor = G4UniformRand() * Z * Z;
180 sinTheta = std::sqrt(1. - cosTheta*cosTheta);
181 gReject = dataFormFactor * dataFormFactor;
182
183 } while( gReject < randomFormFactor);
184
185 // Scattered photon angles. ( Z - axis along the parent photon)
186 G4double phi = twopi * G4UniformRand() ;
187 G4double dirX = sinTheta*std::cos(phi);
188 G4double dirY = sinTheta*std::sin(phi);
189 G4double dirZ = cosTheta;
190
191 // Update G4VParticleChange for the scattered photon
192 G4ThreeVector photonDirection1(dirX, dirY, dirZ);
193
194 photonDirection1.rotateUz(photonDirection0);
195 aParticleChange.ProposeEnergy(photonEnergy0);
196 aParticleChange.ProposeMomentumDirection(photonDirection1);
197
198 aParticleChange.SetNumberOfSecondaries(0);
199
200 return G4VDiscreteProcess::PostStepDoIt(aTrack, aStep);
201}
202
203G4bool G4LowEnergyRayleigh::IsApplicable(const G4ParticleDefinition& particle)
204{
205 return ( &particle == G4Gamma::Gamma() );
206}
207
208G4double G4LowEnergyRayleigh::GetMeanFreePath(const G4Track& track,
209 G4double, // previousStepSize
210 G4ForceCondition*)
211{
212 const G4DynamicParticle* photon = track.GetDynamicParticle();
213 G4double energy = photon->GetKineticEnergy();
214 const G4MaterialCutsCouple* couple = track.GetMaterialCutsCouple();
215 size_t materialIndex = couple->GetIndex();
216
217 G4double meanFreePath;
218 if (energy > highEnergyLimit) meanFreePath = meanFreePathTable->FindValue(highEnergyLimit,materialIndex);
219 else if (energy < lowEnergyLimit) meanFreePath = DBL_MAX;
220 else meanFreePath = meanFreePathTable->FindValue(energy,materialIndex);
221 return meanFreePath;
222}
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