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26 //
27 //////////////////////////////////////////////
28 //
29 // File G4OpMieHG.hh
30 // Description: Discrete Process -- Mie Scatte
31 // Created: 2010-07-03
32 // Author: Xin Qian
33 // Based on work from Vlasios Vasileiou
34 //
35 // This subroutine will mimic the Mie scatteri
36 // Henyey-Greenstein phase function
37 // Forward and backward angles are treated sep
38 //
39 //////////////////////////////////////////////
40
41 #include "G4OpMieHG.hh"
42 #include "G4PhysicalConstants.hh"
43 #include "G4OpticalParameters.hh"
44 #include "G4OpProcessSubType.hh"
45
46 //....oooOO0OOooo........oooOO0OOooo........oo
47 G4OpMieHG::G4OpMieHG(const G4String& processNa
48 : G4VDiscreteProcess(processName, type)
49 {
50 Initialise();
51 if(verboseLevel > 0)
52 {
53 G4cout << GetProcessName() << " is created
54 }
55 SetProcessSubType(fOpMieHG);
56 }
57
58 //....oooOO0OOooo........oooOO0OOooo........oo
59 G4OpMieHG::~G4OpMieHG() = default;
60
61 //....oooOO0OOooo........oooOO0OOooo........oo
62 void G4OpMieHG::PreparePhysicsTable(const G4Pa
63 {
64 Initialise();
65 }
66
67 //....oooOO0OOooo........oooOO0OOooo........oo
68 void G4OpMieHG::Initialise()
69 {
70 SetVerboseLevel(G4OpticalParameters::Instanc
71 }
72
73 //....oooOO0OOooo........oooOO0OOooo........oo
74 G4VParticleChange* G4OpMieHG::PostStepDoIt(con
75 con
76 {
77 aParticleChange.Initialize(aTrack);
78
79 const G4DynamicParticle* aParticle = aTrack.
80 const G4MaterialPropertiesTable* MPT =
81 aTrack.GetMaterial()->GetMaterialPropertie
82
83 G4double forwardRatio = MPT->GetConstPropert
84
85 if(verboseLevel > 1)
86 {
87 G4cout << "OpMie Scattering Photon!" << G4
88 << " Old Momentum Direction: " << a
89 << G4endl
90 << " MIE Old Polarization: " << aPa
91 << G4endl;
92 }
93
94 G4double gg;
95 G4int direction;
96 if(G4UniformRand() <= forwardRatio)
97 {
98 gg = MPT->GetConstProperty(kMIEHG_F
99 direction = 1;
100 }
101 else
102 {
103 gg = MPT->GetConstProperty(kMIEHG_B
104 direction = -1;
105 }
106
107 G4double r = G4UniformRand();
108
109 // sample the direction
110 G4double theta;
111 if(gg != 0.)
112 {
113 theta = std::acos(2. * r * (1. + gg) * (1.
114 ((1. - gg + 2. * gg *
115 1.);
116 }
117 else
118 {
119 theta = std::acos(2. * r - 1.);
120 }
121 G4double phi = G4UniformRand() * twopi;
122
123 if(direction == -1)
124 theta = pi - theta; // backward scatterin
125
126 G4ThreeVector newMomDir, oldMomDir;
127 G4ThreeVector newPol, oldPol;
128
129 G4double sinth = std::sin(theta);
130 newMomDir.set(sinth * std::cos(phi), sinth *
131 oldMomDir = aParticle->GetMomentumDirection(
132 newMomDir.rotateUz(oldMomDir);
133 newMomDir = newMomDir.unit();
134
135 oldPol = aParticle->GetPolarization();
136 newPol = newMomDir - oldPol / newMomDir.dot(
137 newPol = newPol.unit();
138
139 if(newPol.mag() == 0.)
140 {
141 r = G4UniformRand() * twopi;
142 newPol.set(std::cos(r), std::sin(r), 0.);
143 newPol.rotateUz(newMomDir);
144 }
145 else
146 {
147 // There are two directions perpendicular
148 if(G4UniformRand() < 0.5)
149 newPol = -newPol;
150 }
151
152 aParticleChange.ProposePolarization(newPol);
153 aParticleChange.ProposeMomentumDirection(new
154
155 if(verboseLevel > 1)
156 {
157 G4cout << "OpMie New Polarization: " << ne
158 << " Polarization Change: " << *(aP
159 << G4endl << " New Momentum Directi
160 << " Momentum Change: " << *(aParti
161 << G4endl;
162 }
163
164 return G4VDiscreteProcess::PostStepDoIt(aTra
165 }
166
167 //....oooOO0OOooo........oooOO0OOooo........oo
168 G4double G4OpMieHG::GetMeanFreePath(const G4Tr
169 G4ForceCon
170 {
171 G4double attLength = DBL_MAX;
172 G4MaterialPropertiesTable* MPT =
173 aTrack.GetMaterial()->GetMaterialPropertie
174 if(MPT)
175 {
176 G4MaterialPropertyVector* attVector = MPT-
177 if(attVector)
178 {
179 attLength = attVector->Value(
180 aTrack.GetDynamicParticle()->GetTotalE
181 }
182 }
183 return attLength;
184 }
185
186 //....oooOO0OOooo........oooOO0OOooo........oo
187 void G4OpMieHG::SetVerboseLevel(G4int verbose)
188 {
189 verboseLevel = verbose;
190 G4OpticalParameters::Instance()->SetMieVerbo
191 }
192