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28 //
29 // GEANT4 Class file
30 //
31 //
32 // File name: G4UrbanFluctuation
33 //
34 // Author: V. Ivanchenko for Laszlo Urban
35 //
36 // Creation date: 14.02.2022
37 //
38 // Modifications:
39 //
40 //
41
42 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
43 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
44
45 #include "G4UrbanFluctuation.hh"
46 #include "G4PhysicalConstants.hh"
47 #include "G4SystemOfUnits.hh"
48 #include "Randomize.hh"
49 #include "G4Poisson.hh"
50 #include "G4Material.hh"
51 #include "G4Log.hh"
52
53 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
54
55 G4UrbanFluctuation::G4UrbanFluctuation(const G4String& nam)
56 : G4UniversalFluctuation(nam)
57 {}
58
59 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
60
61 G4UrbanFluctuation::~G4UrbanFluctuation() = default;
62
63 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
64
65 G4double G4UrbanFluctuation::SampleGlandz(CLHEP::HepRandomEngine* rndmEngineF,
66 const G4Material* material,
67 const G4double tcut)
68 {
69 if (material != lastMaterial) {
70 auto ioni = material->GetIonisation();
71 f1Fluct = ioni->GetF1fluct();
72 f2Fluct = ioni->GetF2fluct();
73 e1Fluct = ioni->GetEnergy1fluct();
74 e2Fluct = ioni->GetEnergy2fluct();
75 e1LogFluct = ioni->GetLogEnergy1fluct();
76 e2LogFluct = ioni->GetLogEnergy2fluct();
77 esmall = 0.5*std::sqrt(e0*ipotFluct);
78 lastMaterial = material;
79 }
80
81 G4double a1(0.0), a2(0.0), a3(0.0);
82 G4double loss = 0.0;
83 G4double e1 = e1Fluct;
84 G4double e2 = e2Fluct;
85
86 if(tcut > ipotFluct) {
87 if(w2 > ipotLogFluct) {
88 if(w2 > e2LogFluct) {
89 const G4double C = meanLoss*(1.-rate)/(w2-ipotLogFluct);
90 a1 = C*f1Fluct*(w2-e1LogFluct)/e1Fluct;
91 a2 = C*f2Fluct*(w2-e2LogFluct)/e2Fluct;
92 } else {
93 a1 = meanLoss*(1.-rate)/e1;
94 }
95 if(a1 < a0) {
96 const G4double fwnow = 0.5+(fw-0.5)*std::sqrt(a1/a0);
97 a1 /= fwnow;
98 e1 *= fwnow;
99 } else {
100 a1 /= fw;
101 e1 *= fw;
102 }
103 }
104 }
105
106 const G4double w1 = tcut/e0;
107 a3 = rate*meanLoss*(tcut-e0)/(e0*tcut*G4Log(w1));
108 if(a1+a2 <= 0.) { a3 /= rate; }
109
110 //'nearly' Gaussian fluctuation if a1>nmaxCont&&a2>nmaxCont&&a3>nmaxCont
111 G4double emean = 0.;
112 G4double sig2e = 0.;
113
114 // excitation of type 1
115 if(a1 > 0.0) { AddExcitation(rndmEngineF, a1, e1, emean, loss, sig2e); }
116
117 // excitation of type 2
118 if(a2 > 0.0) { AddExcitation(rndmEngineF, a2, e2, emean, loss, sig2e); }
119
120 if(sig2e > 0.0) { SampleGauss(rndmEngineF, emean, sig2e, loss); }
121
122 // ionisation
123 if(a3 > 0.) {
124 emean = 0.;
125 sig2e = 0.;
126 G4double p3 = a3;
127 G4double alfa = 1.;
128 if(a3 > nmaxCont) {
129 alfa = w1*(nmaxCont+a3)/(w1*nmaxCont+a3);
130 const G4double alfa1 = alfa*G4Log(alfa)/(alfa-1.);
131 const G4double namean = a3*w1*(alfa-1.)/((w1-1.)*alfa);
132 emean += namean*e0*alfa1;
133 sig2e += e0*e0*namean*(alfa-alfa1*alfa1);
134 p3 -= namean;
135 }
136
137 const G4double w3 = alfa*e0;
138 if(tcut > w3) {
139 const G4double w = (tcut-w3)/tcut;
140 const G4int nnb = (G4int)G4Poisson(p3);
141 if(nnb > 0) {
142 if(nnb > sizearray) {
143 sizearray = nnb;
144 delete [] rndmarray;
145 rndmarray = new G4double[nnb];
146 }
147 rndmEngineF->flatArray(nnb, rndmarray);
148 for (G4int k=0; k<nnb; ++k) { loss += w3/(1.-w*rndmarray[k]); }
149 }
150 }
151 if(sig2e > 0.0) { SampleGauss(rndmEngineF, emean, sig2e, loss); }
152 }
153 //G4cout << "### loss=" << loss << G4endl;
154 return loss;
155 }
156
157 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
158