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>> 26 // $Id: G4SauterGavrilaAngularDistribution.cc 78929 2014-02-04 09:00:46Z gcosmo $
26 // 27 //
27 // ------------------------------------------- 28 // -------------------------------------------------------------------
28 // 29 //
29 // GEANT4 Class file 30 // GEANT4 Class file
30 // 31 //
31 // 32 //
32 // File name: G4SauterGavrilaAngularDistri 33 // File name: G4SauterGavrilaAngularDistribution
33 // 34 //
34 // Author: Vladimir Ivanchenko using Miche 35 // Author: Vladimir Ivanchenko using Michel Maire algorithm
35 // developed for Geant3 36 // developed for Geant3
36 // 37 //
37 // Creation date: 23 July 2012 38 // Creation date: 23 July 2012
38 // 39 //
39 // Modified: << 40 //
40 // 04.05.2017 Marilena Bandieramonte impleme <<
41 // ------------------------------------------- 41 // -------------------------------------------------------------------
42 // 42 //
43 43
44 #include "G4SauterGavrilaAngularDistribution.h 44 #include "G4SauterGavrilaAngularDistribution.hh"
45 #include "G4PhysicalConstants.hh" 45 #include "G4PhysicalConstants.hh"
46 #include "Randomize.hh" 46 #include "Randomize.hh"
47 47
48 G4SauterGavrilaAngularDistribution::G4SauterGa 48 G4SauterGavrilaAngularDistribution::G4SauterGavrilaAngularDistribution()
49 : G4VEmAngularDistribution("SauterGavrila") << 49 : G4VEmAngularDistribution("AngularGenSauterGavrila")
50 {} 50 {}
51 51
52 G4SauterGavrilaAngularDistribution::~G4SauterG << 52 G4SauterGavrilaAngularDistribution::~G4SauterGavrilaAngularDistribution()
53 = default; << 53 {}
54 54
55 G4ThreeVector& G4SauterGavrilaAngularDistribu << 55 G4ThreeVector&
>> 56 G4SauterGavrilaAngularDistribution::SampleDirection(
56 const G4DynamicParticle* dp, G4double, 57 const G4DynamicParticle* dp, G4double, G4int, const G4Material*)
57 { 58 {
58 static const G4double emin = 1*CLHEP::eV; << 59 G4double tau = dp->GetKineticEnergy()/electron_mass_c2;
59 static const G4double emax = 100*CLHEP::MeV; << 60 static const G4double taulimit = 50.0;
60 61
61 G4double energy = std::max(dp->GetKineticEne << 62 if (tau > taulimit) {
62 if (energy > emax) { << 63 fLocalDirection = dp->GetMomentumDirection();
63 fLocalDirection = dp->GetMomentumDirection << 64 // Bugzilla 1120
>> 65 // SI on 05/09/2010 as suggested by JG 04/09/10
64 } else { 66 } else {
65 // Initial algorithm according Penelope 20 << 67 // algorithm according Penelope 2008 manual and
66 // F.Sauter Ann. Physik 9, 217(1931); 11, << 68 // F.Sauter Ann. Physik 9, 217(1931); 11, 454(1931).
67 // Modified according Penelope 2014 manual << 69
68 G4double costheta = 0.0; << 70 G4double gamma = tau + 1;
69 << 71 G4double beta = std::sqrt(tau*(tau + 2))/gamma;
70 // 1) initialize energy-dependent variable << 72 G4double A = (1 - beta)/beta;
71 // Variable naming according to Eq. (2.24) << 73 G4double Ap2 = A + 2;
72 // (pag. 44) << 74 G4double B = 0.5*beta*gamma*(gamma - 1)*(gamma - 2);
73 G4double tau = energy/electron_mass_c2; << 75 G4double grej = 2*(1 + A*B)/A;
74 G4double gamma = 1.0 + tau; << 76 G4double z, g;
75 G4double beta = std::sqrt(tau*(tau + 2.0)) << 77 do {
76 << 78 G4double q = G4UniformRand();
77 // ac corresponds to "A" of Eq. (2.31) << 79 z = 2*A*(2*q + Ap2*std::sqrt(q))/(Ap2*Ap2 - 4*q);
78 // << 80 g = (2 - z)*(1.0/(A + z) + B);
79 G4double ac = (1.0 - beta)/beta; << 81
80 G4double a1 = 0.5*beta*gamma*tau*(gamma-2. << 82 } while(g < G4UniformRand()*grej);
81 G4double a2 = ac + 2.0; << 83
82 // gtmax = maximum of the rejection functi << 84 G4double cost = 1 - z;
83 // obtained for tsam=0 << 85 G4double sint = std::sqrt(z*(2 - z));
84 G4double gtmax = 2.0*(a1 + 1.0/ac); << 86 G4double phi = CLHEP::twopi*G4UniformRand();
85 << 87
86 G4double tsam = 0.0; << 88 fLocalDirection.set(sint*std::cos(phi), sint*std::sin(phi), cost);
87 G4double gtr = 0.0; <<
88 <<
89 //2) sampling. Eq. (2.31) of Penelope Manu <<
90 // tsam = 1-std::cos(theta) <<
91 // gtr = rejection function according to E <<
92 do{ <<
93 G4double rand = G4UniformRand(); <<
94 tsam = 2.0*ac * (2.0*rand + a2*std::sqrt <<
95 gtr = (2.0 - tsam) * (a1 + 1.0/(ac+tsam) <<
96 // Loop checking, 03-Aug-2015, Vladimir <<
97 } while(G4UniformRand()*gtmax > gtr); <<
98 <<
99 costheta = 1.0 - tsam; <<
100 <<
101 G4double sint = std::sqrt(tsam*(2.0 - tsam <<
102 G4double phi = CLHEP::twopi*G4UniformRand <<
103 <<
104 fLocalDirection.set(sint*std::cos(phi), si <<
105 fLocalDirection.rotateUz(dp->GetMomentumDi 89 fLocalDirection.rotateUz(dp->GetMomentumDirection());
106 } 90 }
107 return fLocalDirection; 91 return fLocalDirection;
108 } 92 }
109 93
110 void G4SauterGavrilaAngularDistribution::Print 94 void G4SauterGavrilaAngularDistribution::PrintGeneratorInformation() const
111 { 95 {
112 G4cout << "\n" << G4endl; 96 G4cout << "\n" << G4endl;
113 G4cout << "Non-polarized photoelectric effec 97 G4cout << "Non-polarized photoelectric effect angular generator." << G4endl;
114 G4cout << "The Sauter-Gavrila distribution f 98 G4cout << "The Sauter-Gavrila distribution for the K-shell is used."<<G4endl;
115 G4cout << "Originally developed by M.Maire f 99 G4cout << "Originally developed by M.Maire for Geant3"
116 << G4endl; << 100 << G4endl;
117 } 101 }
118 <<
119 102