source: trunk/source/processes/electromagnetic/lowenergy/src/G4hBetheBlochModel.cc

Last change on this file was 819, checked in by garnier, 17 years ago

import all except CVS
File size: 7.4 KB
Line 
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//
27// -------------------------------------------------------------------
28//
29// GEANT4 Class file
30//
31//
32// File name: G4hBetheBlochModel
33//
34// Author: V.Ivanchenko (Vladimir.Ivanchenko@cern.ch)
35//
36// Creation date: 20 July 2000
37//
38// Modifications:
39// 20/07/2000 V.Ivanchenko First implementation
40// 03/10/2000 V.Ivanchenko clean up accoding to CodeWizard
41//
42// Class Description:
43//
44// Bethe-Bloch ionisation model
45//
46// Class Description: End
47//
48// -------------------------------------------------------------------
49//
50//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
51
52#include "G4hBetheBlochModel.hh"
53#include "G4DynamicParticle.hh"
54#include "G4ParticleDefinition.hh"
55#include "G4Material.hh"
56#include "globals.hh"
57
58//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
59
60G4hBetheBlochModel::G4hBetheBlochModel(const G4String& name)
61 : G4VLowEnergyModel(name),
62 lowEnergyLimit(1.*MeV),
63 highEnergyLimit(100.*GeV),
64 twoln10(2.*std::log(10.)),
65 bg2lim(0.0169),
66 taulim(8.4146e-3)
67{;}
68
69//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
70
71G4hBetheBlochModel::~G4hBetheBlochModel()
72{;}
73
74//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
75
76G4double G4hBetheBlochModel::TheValue(const G4DynamicParticle* particle,
77 const G4Material* material)
78{
79 G4double energy = particle->GetKineticEnergy() ;
80 G4double particleMass = particle->GetMass() ;
81
82 G4double eloss = BetheBlochFormula(material,energy,particleMass) ;
83
84 return eloss ;
85}
86
87//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
88
89G4double G4hBetheBlochModel::TheValue(const G4ParticleDefinition* aParticle,
90 const G4Material* material,
91 G4double kineticEnergy)
92{
93 G4double particleMass = aParticle->GetPDGMass() ;
94 G4double eloss = BetheBlochFormula(material,kineticEnergy,particleMass) ;
95
96 return eloss ;
97}
98
99//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
100
101G4double G4hBetheBlochModel::HighEnergyLimit(
102 const G4ParticleDefinition* ,
103 const G4Material* ) const
104{
105 return highEnergyLimit ;
106}
107
108//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
109
110G4double G4hBetheBlochModel::LowEnergyLimit(
111 const G4ParticleDefinition* aParticle,
112 const G4Material* material) const
113{
114 G4double taul = (material->GetIonisation()->GetTaul())*
115 (aParticle->GetPDGMass()) ;
116 return taul ;
117}
118
119//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
120
121G4double G4hBetheBlochModel::HighEnergyLimit(
122 const G4ParticleDefinition* ) const
123{
124 return highEnergyLimit ;
125}
126
127//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
128
129G4double G4hBetheBlochModel::LowEnergyLimit(
130 const G4ParticleDefinition* ) const
131{
132 return lowEnergyLimit ;
133}
134
135//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
136
137G4bool G4hBetheBlochModel::IsInCharge(const G4DynamicParticle* ,
138 const G4Material* ) const
139{
140 return true ;
141}
142
143//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
144
145G4bool G4hBetheBlochModel::IsInCharge(const G4ParticleDefinition* ,
146 const G4Material* ) const
147{
148 return true ;
149}
150
151//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
152
153G4double G4hBetheBlochModel::BetheBlochFormula(
154 const G4Material* material,
155 G4double kineticEnergy,
156 G4double particleMass) const
157{
158 // This member function is applied normally to proton/antiproton
159 G4double ionloss ;
160
161 G4double rateMass = electron_mass_c2/particleMass ;
162
163 G4double taul = material->GetIonisation()->GetTaul() ;
164 G4double tau = kineticEnergy/particleMass ; // tau is relative energy
165
166 // It is not normal case for this function
167 // for low energy parametrisation have to be applied
168 if ( tau < taul ) tau = taul ;
169
170 // some local variables
171
172 G4double gamma,bg2,beta2,tmax,x,delta,sh ;
173 G4double electronDensity = material->GetElectronDensity();
174 G4double eexc = material->GetIonisation()->GetMeanExcitationEnergy();
175 G4double eexc2 = eexc*eexc ;
176 G4double cden = material->GetIonisation()->GetCdensity();
177 G4double mden = material->GetIonisation()->GetMdensity();
178 G4double aden = material->GetIonisation()->GetAdensity();
179 G4double x0den = material->GetIonisation()->GetX0density();
180 G4double x1den = material->GetIonisation()->GetX1density();
181 G4double* shellCorrectionVector =
182 material->GetIonisation()->GetShellCorrectionVector();
183
184 gamma = tau + 1.0 ;
185 bg2 = tau*(tau+2.0) ;
186 beta2 = bg2/(gamma*gamma) ;
187 tmax = 2.*electron_mass_c2*bg2/(1.+2.*gamma*rateMass+rateMass*rateMass) ;
188
189 ionloss = std::log(2.0*electron_mass_c2*bg2*tmax/eexc2)-2.0*beta2 ;
190
191 // density correction
192 x = std::log(bg2)/twoln10 ;
193 if ( x < x0den ) {
194 delta = 0.0 ;
195
196 } else {
197 delta = twoln10*x - cden ;
198 if ( x < x1den ) delta += aden*std::pow((x1den-x),mden) ;
199 }
200
201 // shell correction
202 sh = 0.0 ;
203 x = 1.0 ;
204
205 if ( bg2 > bg2lim ) {
206 for (G4int k=0; k<=2; k++) {
207 x *= bg2 ;
208 sh += shellCorrectionVector[k]/x;
209 }
210
211 } else {
212 for (G4int k=0; k<=2; k++) {
213 x *= bg2lim ;
214 sh += shellCorrectionVector[k]/x;
215 }
216 sh *= std::log(tau/taul)/std::log(taulim/taul) ;
217 }
218
219 // now compute the total ionization loss
220
221 ionloss -= delta + sh ;
222 ionloss *= twopi_mc2_rcl2*electronDensity/beta2 ;
223
224 if ( ionloss < 0.0) ionloss = 0.0 ;
225
226 return ionloss;
227}
228
229
Note: See TracBrowser for help on using the repository browser.