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25 //
26 // G4RToEConvForElectron class implementation
27 //
28 // Author: H.Kurashige, 05 October 2002 - First implementation
29 // --------------------------------------------------------------------
30
31 #include "G4RToEConvForElectron.hh"
32 #include "G4ParticleDefinition.hh"
33 #include "G4ParticleTable.hh"
34
35 #include "G4PhysicalConstants.hh"
36 #include "G4SystemOfUnits.hh"
37 #include "G4Pow.hh"
38 #include "G4Log.hh"
39 #include "G4Exp.hh"
40
41 // --------------------------------------------------------------------
42 G4RToEConvForElectron::G4RToEConvForElectron()
43 : G4VRangeToEnergyConverter()
44 {
45 theParticle = G4ParticleTable::GetParticleTable()->FindParticle("e-");
46 if (theParticle == nullptr )
47 {
48 #ifdef G4VERBOSE
49 if (GetVerboseLevel()>0)
50 {
51 G4cout << "G4RToEConvForElectron::G4RToEConvForElectron() - ";
52 G4cout << "Electron is not defined !!" << G4endl;
53 }
54 #endif
55 }
56 else
57 {
58 fPDG = theParticle->GetPDGEncoding();
59 }
60 }
61
62 // --------------------------------------------------------------------
63 G4RToEConvForElectron::~G4RToEConvForElectron()
64 {}
65
66 // --------------------------------------------------------------------
67 G4double G4RToEConvForElectron::ComputeValue(const G4int Z,
68 const G4double kinEnergy)
69 {
70 const G4double cbr1=0.02, cbr2=-5.7e-5, cbr3=1., cbr4=0.072;
71 const G4double Tlow=10.*CLHEP::keV, Thigh=1.*CLHEP::GeV;
72 const G4double taul = Tlow/CLHEP::electron_mass_c2;
73 const G4double log05 = G4Log(0.5);
74 const G4double taul12 = std::sqrt(taul);
75 const G4double bremfactor = 0.1;
76
77 const G4double Zlog = G4Pow::GetInstance()->logZ(Z);
78 const G4double ionpot =
79 1.6e-5*CLHEP::MeV*G4Exp(0.9*Zlog)/CLHEP::electron_mass_c2;
80 const G4double ionpotlog = G4Log(ionpot);
81
82 const G4double tau = kinEnergy/CLHEP::electron_mass_c2;
83 G4double dEdx = 0.0;
84
85 if(tau<taul)
86 {
87 G4double t1 = taul+1.;
88 G4double t2 = taul+2.;
89 G4double tsq = taul*taul;
90 G4double beta2 = taul*t2/(t1*t1);
91 G4double f = 1.-beta2+G4Log(tsq/2.)
92 +(0.5+0.25*tsq+(1.+2.*taul)*log05)/(t1*t1);
93 dEdx = Z*(G4Log(2.*taul+4.)-2.*ionpotlog+f)/beta2;
94 dEdx *= taul12/std::sqrt(tau);
95 }
96 else
97 {
98 G4double t1 = tau+1.;
99 G4double t2 = tau+2.;
100 G4double tsq = tau*tau;
101 G4double beta2 = tau*t2/(t1*t1);
102 G4double f = 1.-beta2+G4Log(tsq/2.)
103 +(0.5+0.25*tsq+(1.+2.*tau)*log05)/(t1*t1);
104 dEdx = Z*(G4Log(2.*tau+4.)-2.*ionpotlog+f)/beta2;
105
106 // loss from bremsstrahlung follows
107 G4double cbrem = (cbr1+cbr2*Z)*(cbr3+cbr4*G4Log(kinEnergy/Thigh));
108 dEdx += Z*(Z+1)*cbrem*bremfactor*tau/beta2;
109 }
110
111 return dEdx*CLHEP::twopi_mc2_rcl2;
112 }
113
114 // --------------------------------------------------------------------
115