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25 //
26 // 19.04.24 V. Grichine, first version
27 //
28
29 #include "G4XTRGaussRadModel.hh"
30 #include "G4PhysicalConstants.hh"
31
32 #include "G4Material.hh"
33 #include "G4Element.hh"
34 #include "G4NistManager.hh"
35
36 using namespace std;
37 using namespace CLHEP;
38
39 //////////////////////////////////////////////
40 // Constructor, destructor
41
42 G4XTRGaussRadModel::G4XTRGaussRadModel(
43 G4LogicalVolume* anEnvelope, G4double alph
44 G4double aa, G4double b, G4int n, const G4St
45 : G4VXTRenergyLoss(anEnvelope, foilMat, gasM
46 {
47 if( verboseLevel > 0 )
48 G4cout << "G4XTRGaussRadModel EM process i
49 << G4endl;
50
51 fAlphaPlate = alphaPlate; // ~40
52 fAlphaGas = alphaGas; // ~10
53 fExitFlux = true; // XTR photons are
54 }
55
56 //////////////////////////////////////////////
57
58 G4XTRGaussRadModel::~G4XTRGaussRadModel() = de
59
60 //////////////////////////////////////////////
61
62 void G4XTRGaussRadModel::ProcessDescription(st
63 {
64 out << "Simulation of forward X-ray transiti
65 "relativistic charged particles cross
66 "two materials.\n";
67 }
68
69 //////////////////////////////////////////////
70
71 G4double G4XTRGaussRadModel::SpectralXTRdEdx(G
72 {
73 static constexpr G4double cofPHC = 4. * pi *
74 G4double result, sum = 0., tmp, cof1, cof2,
75 G4double aMa, bMb, sigma, dump;
76 G4int k, kMax, kMin;
77
78 aMa = fPlateThick * GetPlateLinearPhotoAbs
79 bMb = fGasThick * GetGasLinearPhotoAbs(ene
80 sigma = 0.5 * (aMa + bMb);
81 dump = std::exp(-fPlateNumber * sigma);
82 if(verboseLevel > 2)
83 G4cout << " dump = " << dump << G4endl;
84 tmp = (fSigma1 - fSigma2) / cofPHC / energy
85 cof1 = fPlateThick * tmp;
86 cof2 = fGasThick * tmp;
87
88 cofMin = energy * (fPlateThick + fGasThick)
89 cofMin += (fPlateThick * fSigma1 + fGasThick
90 cofMin /= cofPHC;
91
92 theta2 = cofPHC / (energy * (fPlateThick + f
93
94 kMin = G4int(cofMin);
95 if(cofMin > kMin)
96 kMin++;
97
98 kMax = kMin + 200; // 99; // 49; //
99
100 if(verboseLevel > 2)
101 {
102 G4cout << cof1 << " " << cof2 << "
103 G4cout << "kMin = " << kMin << "; kMax
104 }
105 for(k = kMin; k <= kMax; ++k)
106 {
107 tmp = pi * fPlateThick * (k + cof2) / (
108 result = (k - cof1) * (k - cof1) * (k + co
109 if(k == kMin && kMin == G4int(cofMin))
110 {
111 sum +=
112 0.5 * std::sin(tmp) * std::sin(tmp) *
113 }
114 else
115 {
116 sum += std::sin(tmp) * std::sin(tmp) * s
117 }
118 theta2k = std::sqrt(theta2 * std::abs(k -
119
120 if(verboseLevel > 2)
121 {
122 G4cout << k << " " << theta2k << "
123 << std::sin(tmp) * std::sin(tmp)
124 << " " << sum << G4endl;
125 }
126 }
127 result = 2 * (cof1 + cof2) * (cof1 + cof2) *
128 result *= dump * (-1 + dump + 2 * fPlateNumb
129 return result;
130 }
131
132 //////////////////////////////////////////////
133 //
134 // Approximation for radiator interference fac
135 // Gauss-distributed regular radiator. The pla
136 // are Gauss distributed with RMS
137 // sa and sb for plate and gas, respectively.
138 // The mean values of the plate and gas gap th
139 // are supposed to be about XTR formation zone
140 // The XTR photons are moved to the end of rad
141
142
143 G4double G4XTRGaussRadModel::GetStackFactor(G4
144
145
146 {
147 G4double result(0.);
148
149 G4double Ma, Mb, aMa, bMb, sigma;
150
151 G4double sa = fPlateThick/fAlphaPlate;
152 G4double sb = fGasThick/fAlphaGas;
153
154 Ma = GetPlateLinearPhotoAbs(energy);
155 aMa = fPlateThick * Ma;
156 Mb = GetGasLinearPhotoAbs(energy);
157 bMb = fGasThick * Mb;
158 sigma = aMa + bMb; // m1*t1+m2*t2 dimensionl
159 G4double nn = G4double( fPlateNumber );
160
161 // Gauss fluctuation of foil and gas gaps ac
162 // RMS = sa = a/fAlphaPlate and RMS = sb = b
163
164 G4complex med(0.,1.);
165 G4complex Z1 = GetPlateComplexFZ( energy,
166 G4complex por1 = -0.5*med*fPlateThick/Z1 - 0
167
168 G4complex Z2 = GetGasComplexFZ( energy, ga
169 G4complex por2 = -0.5*med*fGasThick/Z2 - 0.1
170
171 G4complex npor = (por1+por2)*nn;
172
173 G4complex Ha = exp(por1);
174 G4complex Hb = exp(por2);
175
176 G4complex H = Ha*Hb;
177 G4complex Hn = exp(npor);
178
179 G4complex A = ( 1.0 - Ha ) * ( 1.0 - Hb ) /
180 G4complex B1 = ( 1.0 - Ha ) * ( 1.0 - Ha ) *
181
182 G4complex R = B1*( exp(-sigma*nn) - Hn )/(
183
184 R += A * ( 1 - exp(-sigma*nn) ) / ( 1. - exp
185
186 R *= OneInterfaceXTRdEdx(energy, gamma, varA
187
188 result = 2.0 * std::real(R);
189
190 return result;
191 }
192