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237c933d | 1 | /************************************************************************** |
2 | * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. * | |
3 | * * | |
4 | * Author: The ALICE Off-line Project. * | |
5 | * Contributors are mentioned in the code where appropriate. * | |
6 | * * | |
7 | * Permission to use, copy, modify and distribute this software and its * | |
8 | * documentation strictly for non-commercial purposes is hereby granted * | |
9 | * without fee, provided that the above copyright notice appears in all * | |
10 | * copies and that both the copyright notice and this permission notice * | |
11 | * appear in the supporting documentation. The authors make no claims * | |
12 | * about the suitability of this software for any purpose. It is * | |
13 | * provided "as is" without express or implied warranty. * | |
14 | **************************************************************************/ | |
15 | ||
16 | /* | |
17 | $Log$ | |
ababa188 | 18 | Revision 1.8 2001/09/05 09:09:38 hristov |
19 | The energy of feedback photons calculated correctly | |
20 | ||
d9042b8a | 21 | Revision 1.7 2001/05/10 12:32:27 jbarbosa |
22 | Changed call to SetTrack. | |
23 | ||
3c5ffeb4 | 24 | Revision 1.6 2001/02/23 17:39:02 jbarbosa |
25 | Removed verbose output. | |
26 | ||
d65c4a20 | 27 | Revision 1.5 2001/02/23 17:25:08 jbarbosa |
28 | Re-definition of IntPH() to accomodate for wire sag effect. | |
29 | ||
733b4fa4 | 30 | Revision 1.4 2000/12/01 17:37:44 morsch |
31 | Replace in argument of SetTrack(..) string constant by kPFeedBackPhoton. | |
32 | ||
9e4670f0 | 33 | Revision 1.3 2000/10/03 21:44:09 morsch |
34 | Use AliSegmentation and AliHit abstract base classes. | |
35 | ||
a2f7eaf6 | 36 | Revision 1.2 2000/10/02 21:28:12 fca |
37 | Removal of useless dependecies via forward declarations | |
38 | ||
94de3818 | 39 | Revision 1.1 2000/06/12 15:29:37 jbarbosa |
40 | Cleaned up version. | |
41 | ||
237c933d | 42 | */ |
43 | ||
44 | #include "AliRICHResponseV0.h" | |
a2f7eaf6 | 45 | #include "AliSegmentation.h" |
237c933d | 46 | #include "AliRun.h" |
94de3818 | 47 | #include "AliMC.h" |
237c933d | 48 | |
49 | #include <TMath.h> | |
50 | #include <TRandom.h> | |
51 | #include <TParticle.h> | |
52 | //___________________________________________ | |
53 | ClassImp(AliRICHResponseV0) | |
54 | ||
ababa188 | 55 | AliRICHResponseV0::AliRICHResponseV0() |
56 | { | |
57 | SetSigmaIntegration(5.); | |
58 | SetChargeSlope(27.); | |
59 | SetChargeSpread(0.18, 0.18); | |
60 | SetMaxAdc(4096); | |
61 | SetAlphaFeedback(0.036); | |
62 | SetEIonisation(26.e-9); | |
63 | SetSqrtKx3(0.77459667); | |
64 | SetKx2(0.962); | |
65 | SetKx4(0.379); | |
66 | SetSqrtKy3(0.77459667); | |
67 | SetKy2(0.962); | |
68 | SetKy4(0.379); | |
69 | SetPitch(0.25); | |
70 | SetWireSag(1); // 1->On, 0->Off | |
71 | SetVoltage(2150); // Should only be 2000, 2050, 2100 or 2150 | |
72 | }//AliRICHResponseV0::ctor() | |
733b4fa4 | 73 | Float_t AliRICHResponseV0::IntPH(Float_t eloss, Float_t yhit) |
237c933d | 74 | { |
75 | // Get number of electrons and return charge | |
76 | ||
77 | Int_t nel; | |
78 | nel= Int_t(eloss/fEIonisation); | |
79 | ||
80 | Float_t charge=0; | |
733b4fa4 | 81 | Double_t gain_var=1; |
82 | ||
237c933d | 83 | if (nel == 0) nel=1; |
733b4fa4 | 84 | |
85 | if (fWireSag) | |
86 | { | |
87 | //printf("Voltage:%d, Yhit:%f\n",fVoltage, yhit); | |
88 | ||
89 | if (fVoltage==2150) | |
90 | { | |
91 | gain_var = 9e-6*TMath::Power(yhit,4) + 2e-7*TMath::Power(yhit,3) - 0.0316*TMath::Power(yhit,2) - 3e-4*yhit + 25.367; | |
92 | //gain_var = 9e-5*TMath::Power(yhit,4) + 2e-6*TMath::Power(yhit,3) - 0.316*TMath::Power(yhit,2) - 3e-3*yhit + 253.67; | |
93 | } | |
94 | if (fVoltage==2100) | |
95 | gain_var = 8e-6*TMath::Power(yhit,4) + 2e-7*TMath::Power(yhit,3) - 0.0283*TMath::Power(yhit,2) - 2e-4*yhit + 23.015; | |
96 | if (fVoltage==2050) | |
97 | gain_var = 7e-6*TMath::Power(yhit,4) + 1e-7*TMath::Power(yhit,3) - 0.0254*TMath::Power(yhit,2) - 2e-4*yhit + 20.888; | |
98 | if (fVoltage==2000) | |
99 | gain_var = 6e-6*TMath::Power(yhit,4) + 8e-8*TMath::Power(yhit,3) - 0.0227*TMath::Power(yhit,2) - 1e-4*yhit + 18.961; | |
100 | ||
101 | gain_var = gain_var/100; | |
102 | //printf("Yhit:%f, Gain variation:%f\n",yhit,gain_var); | |
103 | ||
104 | Float_t gain = (fChargeSlope + fChargeSlope*gain_var)*.9; | |
d65c4a20 | 105 | //printf(" Yhit:%f, Gain variation:%f\n",yhit, gain); |
733b4fa4 | 106 | |
107 | for (Int_t i=1;i<=nel;i++) { | |
108 | charge -= gain*TMath::Log(gRandom->Rndm()); | |
109 | } | |
110 | } | |
111 | else | |
112 | { | |
113 | for (Int_t i=1;i<=nel;i++) { | |
114 | charge -= fChargeSlope*TMath::Log(gRandom->Rndm()); | |
115 | } | |
116 | } | |
117 | ||
237c933d | 118 | return charge; |
119 | } | |
120 | ||
733b4fa4 | 121 | Float_t AliRICHResponseV0::IntPH(Float_t yhit) |
237c933d | 122 | { |
123 | ||
124 | // Get number of electrons and return charge, for a single photon | |
125 | ||
733b4fa4 | 126 | Float_t charge=0; |
127 | Double_t gain_var=1; | |
128 | ||
129 | if (fWireSag) | |
130 | { | |
131 | if (fVoltage==2150) | |
132 | { | |
133 | gain_var = 9e-6*TMath::Power(yhit,4) + 2e-7*TMath::Power(yhit,3) - 0.0316*TMath::Power(yhit,2) - 3e-4*yhit + 25.367; | |
134 | //gain_var = 9e-5*TMath::Power(yhit,4) + 2e-6*TMath::Power(yhit,3) - 0.316*TMath::Power(yhit,2) - 3e-3*yhit + 253.67; | |
135 | } | |
136 | if (fVoltage==2100) | |
137 | gain_var = 8e-6*TMath::Power(yhit,4) + 2e-7*TMath::Power(yhit,3) - 0.0283*TMath::Power(yhit,2) - 2e-4*yhit + 23.015; | |
138 | if (fVoltage==2050) | |
139 | gain_var = 7e-6*TMath::Power(yhit,4) + 1e-7*TMath::Power(yhit,3) - 0.0254*TMath::Power(yhit,2) - 2e-4*yhit + 20.888; | |
140 | if (fVoltage==2000) | |
141 | gain_var = 6e-6*TMath::Power(yhit,4) + 8e-8*TMath::Power(yhit,3) - 0.0227*TMath::Power(yhit,2) - 1e-4*yhit + 18.961; | |
142 | ||
143 | gain_var = gain_var/100; | |
144 | //printf(" Yhit:%f, Gain variation:%f\n",yhit, gain_var); | |
145 | ||
146 | Float_t gain = (fChargeSlope + fChargeSlope*gain_var)*.9; | |
147 | ||
148 | charge -= gain*TMath::Log(gRandom->Rndm()); | |
d65c4a20 | 149 | //printf(" Yhit:%f, Gain variation:%f\n",yhit, gain); |
733b4fa4 | 150 | } |
151 | else | |
152 | { | |
153 | charge -= fChargeSlope*TMath::Log(gRandom->Rndm()); | |
154 | } | |
237c933d | 155 | return charge; |
156 | } | |
157 | ||
158 | ||
159 | ||
160 | // ------------------------------------------- | |
a2f7eaf6 | 161 | Float_t AliRICHResponseV0::IntXY(AliSegmentation * segmentation) |
237c933d | 162 | { |
163 | ||
164 | const Float_t kInversePitch = 1/fPitch; | |
165 | Float_t response; | |
166 | // | |
167 | // Integration limits defined by segmentation model | |
168 | // | |
169 | ||
170 | Float_t xi1, xi2, yi1, yi2; | |
171 | segmentation->IntegrationLimits(xi1,xi2,yi1,yi2); | |
172 | ||
173 | xi1=xi1*kInversePitch; | |
174 | xi2=xi2*kInversePitch; | |
175 | yi1=yi1*kInversePitch; | |
176 | yi2=yi2*kInversePitch; | |
177 | ||
178 | //printf("Integration Limits: %f-%f, %f-%f\n",xi1,xi2,yi1,yi2); | |
179 | ||
180 | //printf("KInversePitch:%f\n",kInversePitch); | |
181 | ||
182 | // | |
183 | // The Mathieson function | |
184 | Double_t ux1=fSqrtKx3*TMath::TanH(fKx2*xi1); | |
185 | Double_t ux2=fSqrtKx3*TMath::TanH(fKx2*xi2); | |
186 | ||
187 | Double_t uy1=fSqrtKy3*TMath::TanH(fKy2*yi1); | |
188 | Double_t uy2=fSqrtKy3*TMath::TanH(fKy2*yi2); | |
189 | ||
190 | //printf("Integration Data: %f-%f, %f-%f\n",ux1,ux2,uy1,uy2); | |
191 | ||
192 | //printf("%f %f %f %f\n",fSqrtKx3,fKx2,fKy4,fKx4); | |
193 | ||
194 | response=4.*fKx4*(TMath::ATan(ux2)-TMath::ATan(ux1))*fKy4*(TMath::ATan(uy2)-TMath::ATan(uy1)); | |
195 | ||
196 | //printf("Response:%f\n",response); | |
197 | ||
198 | return response; | |
199 | ||
200 | } | |
201 | ||
202 | Int_t AliRICHResponseV0::FeedBackPhotons(Float_t *source, Float_t qtot) | |
203 | { | |
204 | // | |
205 | // Generate FeedBack photons | |
206 | // | |
207 | Int_t j, ipart, nt; | |
208 | ||
209 | Int_t sNfeed=0; | |
210 | ||
211 | ||
212 | // Local variables | |
213 | Float_t cthf, ranf[2], phif, enfp = 0, sthf; | |
214 | Int_t i, ifeed; | |
215 | Float_t e1[3], e2[3], e3[3]; | |
216 | Float_t vmod, uswop; | |
217 | Float_t fp, random; | |
218 | Float_t dir[3], phi; | |
219 | Int_t nfp; | |
d9042b8a | 220 | Float_t pol[3], mom[4]; |
237c933d | 221 | TLorentzVector position; |
222 | // | |
223 | // Determine number of feedback photons | |
224 | ||
225 | // Get weight of current particle | |
226 | TParticle *current = (TParticle*) | |
227 | (*gAlice->Particles())[gAlice->CurrentTrack()]; | |
228 | ||
229 | ifeed = Int_t(current->GetWeight()/100+0.5); | |
230 | ipart = gMC->TrackPid(); | |
231 | fp = fAlphaFeedback * qtot; | |
232 | nfp = gRandom->Poisson(fp); | |
233 | ||
234 | // This call to fill the time of flight | |
235 | gMC->TrackPosition(position); | |
3c5ffeb4 | 236 | //printf("Track position: %f %f %f %15.12f\n", position[0],position[1],position[2],position[3]); |
237c933d | 237 | // |
238 | // Generate photons | |
239 | for (i = 0; i <nfp; i++) { | |
240 | ||
241 | // Direction | |
242 | gMC->Rndm(ranf, 2); | |
243 | cthf = ranf[0] * 2 - 1.; | |
244 | if (cthf < 0) continue; | |
245 | sthf = TMath::Sqrt((1 - cthf) * (1 + cthf)); | |
246 | phif = ranf[1] * 2 * TMath::Pi(); | |
247 | // | |
248 | gMC->Rndm(&random, 1); | |
249 | if (random <= .57) { | |
250 | enfp = 7.5e-9; | |
251 | } else if (random <= .7) { | |
252 | enfp = 6.4e-9; | |
253 | } else { | |
254 | enfp = 7.9e-9; | |
255 | } | |
256 | ||
257 | dir[0] = sthf * TMath::Sin(phif); | |
258 | dir[1] = cthf; | |
259 | dir[2] = sthf * TMath::Cos(phif); | |
260 | gMC->Gdtom(dir, mom, 2); | |
261 | mom[0]*=enfp; | |
262 | mom[1]*=enfp; | |
263 | mom[2]*=enfp; | |
d9042b8a | 264 | mom[3] = TMath::Sqrt(mom[0]*mom[0]+mom[1]*mom[1]+mom[2]*mom[2]); |
3c5ffeb4 | 265 | //printf("Dir %f %f %f\n",dir[0],dir[1],dir[2]); |
266 | //printf("Momentum %15.12f %15.12f %15.12f\n",mom[0],mom[1],mom[2]); | |
d9042b8a | 267 | //printf("Energy %e\n", mom[3]); |
237c933d | 268 | |
269 | // Polarisation | |
270 | e1[0] = 0; | |
271 | e1[1] = -dir[2]; | |
272 | e1[2] = dir[1]; | |
273 | ||
274 | e2[0] = -dir[1]; | |
275 | e2[1] = dir[0]; | |
276 | e2[2] = 0; | |
277 | ||
278 | e3[0] = dir[1]; | |
279 | e3[1] = 0; | |
280 | e3[2] = -dir[0]; | |
281 | ||
282 | vmod=0; | |
283 | for(j=0;j<3;j++) vmod+=e1[j]*e1[j]; | |
284 | if (!vmod) for(j=0;j<3;j++) { | |
285 | uswop=e1[j]; | |
286 | e1[j]=e3[j]; | |
287 | e3[j]=uswop; | |
288 | } | |
289 | vmod=0; | |
290 | for(j=0;j<3;j++) vmod+=e2[j]*e2[j]; | |
291 | if (!vmod) for(j=0;j<3;j++) { | |
292 | uswop=e2[j]; | |
293 | e2[j]=e3[j]; | |
294 | e3[j]=uswop; | |
295 | } | |
296 | ||
297 | vmod=0; | |
298 | for(j=0;j<3;j++) vmod+=e1[j]*e1[j]; | |
299 | vmod=TMath::Sqrt(1/vmod); | |
300 | for(j=0;j<3;j++) e1[j]*=vmod; | |
301 | ||
302 | vmod=0; | |
303 | for(j=0;j<3;j++) vmod+=e2[j]*e2[j]; | |
304 | vmod=TMath::Sqrt(1/vmod); | |
305 | for(j=0;j<3;j++) e2[j]*=vmod; | |
306 | ||
307 | gMC->Rndm(ranf, 1); | |
308 | phi = ranf[0] * 2 * TMath::Pi(); | |
309 | for(j=0;j<3;j++) pol[j]=e1[j]*TMath::Sin(phi)+e2[j]*TMath::Cos(phi); | |
310 | gMC->Gdtom(pol, pol, 2); | |
311 | ||
312 | // Put photon on the stack and label it as feedback (51, 52) | |
313 | ++sNfeed; | |
314 | ||
315 | gAlice->SetTrack(Int_t(1), gAlice->CurrentTrack(), Int_t(50000051), | |
3c5ffeb4 | 316 | mom[0],mom[1],mom[2],mom[3],source[0],source[1],source[2],position[3],pol[0],pol[1],pol[2], |
9e4670f0 | 317 | kPFeedBackPhoton, nt, 1.); |
3c5ffeb4 | 318 | |
319 | //printf("Adding feedback with tof %f and going to %f %f %f\n",position[3],mom[0],mom[1],mom[2]); | |
237c933d | 320 | } |
3c5ffeb4 | 321 | //if(sNfeed) |
322 | //printf("feedbacks produced:%d\n",sNfeed); | |
237c933d | 323 | return(sNfeed); |
324 | } | |
325 | ||
326 | ||
327 | ||
328 |