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25 //
26
27 #include "G4GammaXTRadiator.hh"
28
29 #include "G4Gamma.hh"
30
31 ////////////////////////////////////////////////////////////////////////////
32 // Constructor, destructor
33 G4GammaXTRadiator::G4GammaXTRadiator(G4LogicalVolume* anEnvelope,
34 G4double alphaPlate, G4double alphaGas,
35 G4Material* foilMat, G4Material* gasMat,
36 G4double a, G4double b, G4int n,
37 const G4String& processName)
38 : G4VXTRenergyLoss(anEnvelope, foilMat, gasMat, a, b, n, processName)
39 {
40 G4cout << "Gamma distributed X-ray TR radiator model is called" << G4endl;
41
42 // Build energy and angular integral spectra of X-ray TR photons from
43 // a radiator
44
45 fAlphaPlate = alphaPlate;
46 fAlphaGas = alphaGas;
47 G4cout << "fAlphaPlate = " << fAlphaPlate << " ; fAlphaGas = " << fAlphaGas
48 << G4endl;
49 }
50
51 ///////////////////////////////////////////////////////////////////////////
52 G4GammaXTRadiator::~G4GammaXTRadiator() = default;
53
54 void G4GammaXTRadiator::ProcessDescription(std::ostream& out) const
55 {
56 out
57 << "Rough approximation describing a radiator of X-ray transition "
58 "radiation.\n"
59 "Thicknesses of plates and gas gaps are distributed according to gamma\n"
60 "description.\n";
61 }
62
63 ///////////////////////////////////////////////////////////////////////////
64 // Rough approximation for radiator interference factor for the case of
65 // fully GamDistr radiator. The plate and gas gap thicknesses are distributed
66 // according to exponent. The mean values of the plate and gas gap thicknesses
67 // are supposed to be about XTR formation zones but much less than
68 // mean absorption length of XTR photons in corresponding material.
69 G4double G4GammaXTRadiator::GetStackFactor(G4double energy, G4double gamma,
70 G4double varAngle)
71 {
72 G4double result, Za, Zb, Ma, Mb;
73
74 Za = GetPlateFormationZone(energy, gamma, varAngle);
75 Zb = GetGasFormationZone(energy, gamma, varAngle);
76
77 Ma = GetPlateLinearPhotoAbs(energy);
78 Mb = GetGasLinearPhotoAbs(energy);
79
80 G4complex Ca(1.0 + 0.5 * fPlateThick * Ma / fAlphaPlate,
81 fPlateThick / Za / fAlphaPlate);
82 G4complex Cb(1.0 + 0.5 * fGasThick * Mb / fAlphaGas,
83 fGasThick / Zb / fAlphaGas);
84
85 G4complex Ha = std::pow(Ca, -fAlphaPlate);
86 G4complex Hb = std::pow(Cb, -fAlphaGas);
87 G4complex H = Ha * Hb;
88
89 G4complex F1 = (1.0 - Ha) * (1.0 - Hb) / (1.0 - H) * G4double(fPlateNumber);
90
91 G4complex F2 = (1.0 - Ha) * (1.0 - Ha) * Hb / (1.0 - H) / (1.0 - H) *
92 (1.0 - std::pow(H, fPlateNumber));
93
94 G4complex R = (F1 + F2) * OneInterfaceXTRdEdx(energy, gamma, varAngle);
95
96 result = 2.0 * std::real(R);
97
98 return result;
99 }
100