| Geant4 Cross Reference |
1 // 1
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17 // *
18 // * This code implementation is the result
19 // * technical work of the GEANT4 collaboratio
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24 // *******************************************
25 //
26
27 #include "G4StrawTubeXTRadiator.hh"
28
29 #include "G4Gamma.hh"
30 #include "G4PhysicalConstants.hh"
31 #include "G4SystemOfUnits.hh"
32
33 //////////////////////////////////////////////
34 // Constructor, destructor
35 G4StrawTubeXTRadiator::G4StrawTubeXTRadiator(G
36 G
37 G
38 G
39 G
40 c
41 : G4VXTRenergyLoss(anEnvelope, foilMat, gasM
42 {
43 if(verboseLevel > 0)
44 G4cout << "Straw tube X-ray TR radiator E
45
46 if(unishut)
47 {
48 fAlphaPlate = 1. / 3.;
49 fAlphaGas = 12.4;
50 if(verboseLevel > 0)
51 G4cout << "straw uniform shooting: "
52 << "fAlphaPlate = " << fAlphaPlat
53 << " ; fAlphaGas = " << fAlphaGas
54 }
55 else
56 {
57 fAlphaPlate = 0.5;
58 fAlphaGas = 5.;
59 if(verboseLevel > 0)
60 G4cout << "straw isotropical shooting: "
61 << "fAlphaPlate = " << fAlphaPlat
62 << " ; fAlphaGas = " << fAlphaGas
63 }
64
65 // index of medium material
66 fMatIndex3 = (G4int)mediumMat->GetIndex();
67 if(verboseLevel > 0)
68 G4cout << "medium material = " << mediumMa
69
70 // plasma energy squared for plate material
71 fSigma3 = fPlasmaCof * mediumMat->GetElectro
72 if(verboseLevel > 0)
73 G4cout << "medium plasma energy = " << std
74 << G4endl;
75
76 // Compute cofs for preparation of linear ph
77 ComputeMediumPhotoAbsCof();
78 }
79
80 //////////////////////////////////////////////
81 G4StrawTubeXTRadiator::~G4StrawTubeXTRadiator(
82
83 void G4StrawTubeXTRadiator::ProcessDescription
84 {
85 out << "Simulation of forward X-ray transiti
86 "a straw tube radiator.\n";
87 }
88
89 //////////////////////////////////////////////
90 // Approximation for radiator interference fac
91 // straw tube radiator. The plate (window, str
92 // gap thicknesses are gamma distributed.
93 // The mean values of the plate and gas gap th
94 // are supposed to be about XTR formation zone
95 G4double G4StrawTubeXTRadiator::GetStackFactor
96
97 {
98 G4double result, L2, L3, M2, M3;
99
100 L2 = GetPlateFormationZone(energy, gamma, va
101 L3 = GetGasFormationZone(energy, gamma, varA
102
103 M2 = GetPlateLinearPhotoAbs(energy);
104 M3 = GetGasLinearPhotoAbs(energy);
105
106 G4complex C2(1.0 + 0.5 * fPlateThick * M2 /
107 fPlateThick / L2 / fAlphaPlate)
108 G4complex C3(1.0 + 0.5 * fGasThick * M3 / fA
109 fGasThick / L3 / fAlphaGas);
110
111 G4complex H2 = std::pow(C2, -fAlphaPlate);
112 G4complex H3 = std::pow(C3, -fAlphaGas);
113 G4complex H = H2 * H3;
114
115 G4complex Z1 = GetMediumComplexFZ(energy, ga
116 G4complex Z2 = GetPlateComplexFZ(energy, gam
117 G4complex Z3 = GetGasComplexFZ(energy, gamma
118
119 G4complex R = (Z1 - Z2) * (Z1 - Z2) * (1. -
120 (Z2 - Z3) * (Z2 - Z3) * (1. -
121 2. * (Z1 - Z2) * (Z2 - Z3) * H
122
123 result = 2.0 * std::real(R) * (varAngle * en
124
125 return result;
126 }
127
128 //////////////////////////////////////////////
129 // Calculates formation zone for external medi
130 G4double G4StrawTubeXTRadiator::GetMediumForma
131
132
133 {
134 G4double cof, lambda;
135 lambda = 1.0 / gamma / gamma + varAngle + fS
136 cof = 2.0 * hbarc / omega / lambda;
137 return cof;
138 }
139
140 //////////////////////////////////////////////
141 // Calculates complex formation zone for exter
142 G4complex G4StrawTubeXTRadiator::GetMediumComp
143
144
145 {
146 G4double cof, length, delta, real_v, image_v
147
148 length = 0.5 * GetMediumFormationZone(omega,
149 delta = length * GetMediumLinearPhotoAbs(om
150 cof = 1.0 / (1.0 + delta * delta);
151
152 real_v = length * cof;
153 image_v = real_v * delta;
154
155 G4complex zone(real_v, image_v);
156 return zone;
157 }
158
159 //////////////////////////////////////////////
160 // Computes matrix of Sandia photo absorption
161 // medium material
162 void G4StrawTubeXTRadiator::ComputeMediumPhoto
163 {
164 const G4MaterialTable* theMaterialTable = G4
165 const G4Material* mat = (*
166 fMediumPhotoAbsCof = ma
167 }
168
169 //////////////////////////////////////////////
170 // Returns the value of linear photo absorptio
171 // length) for medium for given energy of X-ra
172 G4double G4StrawTubeXTRadiator::GetMediumLinea
173 {
174 G4double omega2, omega3, omega4;
175
176 omega2 = omega * omega;
177 omega3 = omega2 * omega;
178 omega4 = omega2 * omega2;
179
180 const G4double* SandiaCof =
181 fMediumPhotoAbsCof->GetSandiaCofForMateria
182
183 G4double cross = SandiaCof[0] / omega + Sand
184 SandiaCof[2] / omega3 + San
185 return cross;
186 }
187