source: trunk/source/processes/electromagnetic/highenergy/src/G4eeToPGammaModel.cc@ 1201

Last change on this file since 1201 was 1196, checked in by garnier, 16 years ago

update CVS release candidate geant4.9.3.01
File size: 4.9 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// $Id: G4eeToPGammaModel.cc,v 1.2 2009/02/20 16:38:33 vnivanch Exp $
27// GEANT4 tag $Name: geant4-09-03-cand-01 $
28//
29// -------------------------------------------------------------------
30//
31// GEANT4 Class header file
32//
33//
34// File name: G4eeToPGammaModel
35//
36// Author: Vladimir Ivanchenko
37//
38// Creation date: 25.10.2003
39//
40// Modifications:
41//
42//
43// -------------------------------------------------------------------
44//
45
46
47//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
48//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
49
50#include "G4eeToPGammaModel.hh"
51#include "Randomize.hh"
52#include "G4PionZero.hh"
53#include "G4Eta.hh"
54#include "G4Gamma.hh"
55#include "G4DynamicParticle.hh"
56#include "G4PhysicsVector.hh"
57#include "G4PhysicsLinearVector.hh"
58#include "G4eeCrossSections.hh"
59
60//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
61
62using namespace std;
63
64G4eeToPGammaModel::G4eeToPGammaModel(G4eeCrossSections* cr, const G4String& npart):
65 cross(cr)
66{
67 pi0 = G4PionZero::PionZero();
68 if(npart == "pi0") {
69 massR = 782.62*MeV;
70 particle = pi0;
71 } else {
72 massR = 1019.46*MeV;
73 particle = G4Eta::Eta();
74 }
75 massP = particle->GetPDGMass();
76}
77
78//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
79
80G4eeToPGammaModel::~G4eeToPGammaModel()
81{}
82
83//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
84
85G4double G4eeToPGammaModel::ThresholdEnergy() const
86{
87 return LowEnergy();
88}
89
90//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
91
92G4double G4eeToPGammaModel::PeakEnergy() const
93{
94 return massR;
95}
96
97//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
98
99G4double G4eeToPGammaModel::ComputeCrossSection(G4double e) const
100{
101 G4double ee = std::min(HighEnergy(),e);
102 G4double xs;
103 if(particle == pi0) xs = cross->CrossSectionPi0G(ee);
104 else xs = cross->CrossSectionEtaG(ee);
105 return xs;
106}
107
108//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
109
110G4PhysicsVector* G4eeToPGammaModel::PhysicsVector(G4double emin,
111 G4double emax) const
112{
113 G4double tmin = std::max(emin, ThresholdEnergy());
114 G4double tmax = std::max(tmin, emax);
115 G4int nbins = (G4int)((tmax - tmin)/(5.*MeV));
116 G4PhysicsVector* v = new G4PhysicsLinearVector(emin,emax,nbins);
117 v->SetSpline(true);
118 return v;
119}
120
121//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
122
123void G4eeToPGammaModel::SampleSecondaries(std::vector<G4DynamicParticle*>* newp,
124 G4double e, const G4ThreeVector& direction)
125{
126 G4double egam = 0.5*e*(1.0 - massP*massP/(massR*massR));
127 G4double tkin = e - egam - massP;
128 if(tkin < 0.0) tkin = 0.0;
129 G4double cost;
130 do {
131 cost = 2.0*G4UniformRand() - 1.0;
132 } while( 2.0*G4UniformRand() > 1.0 + cost*cost );
133
134 G4double sint = sqrt(1.0 - cost*cost);
135 G4double phi = twopi * G4UniformRand();
136
137 G4ThreeVector dir(sint*cos(phi),sint*sin(phi), cost);
138 dir.rotateUz(direction);
139
140 // create G4DynamicParticle objects
141 G4DynamicParticle* p1 =
142 new G4DynamicParticle(particle,dir,tkin);
143 G4DynamicParticle* p2 =
144 new G4DynamicParticle(G4Gamma::Gamma(),-dir,egam);
145 newp->push_back(p1);
146 newp->push_back(p2);
147}
148
149//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
150
Note: See TracBrowser for help on using the repository browser.