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46d29e70 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
88cb7938 16/* $Id$ */
46d29e70 17
18///////////////////////////////////////////////////////////////////////////////
19// //
20// TRD simulation - multimodule (regular rad.) //
21// after: M. CASTELLANO et al., COMP. PHYS. COMM. 51 (1988) 431 //
22// + COMP. PHYS. COMM. 61 (1990) 395 //
23// //
24// 17.07.1998 - A.Andronic //
25// 08.12.1998 - simplified version //
26// 11.07.2000 - Adapted code to aliroot environment (C.Blume) //
27// //
28///////////////////////////////////////////////////////////////////////////////
29
30#include <stdlib.h>
31
0e9c2ad5 32#include <TH1.h>
33#include <TRandom.h>
34#include <TMath.h>
35#include <TParticle.h>
46d29e70 36
46d29e70 37#include "AliModule.h"
38
0e9c2ad5 39#include "AliTRDsim.h"
40
46d29e70 41ClassImp(AliTRDsim)
42
43//_____________________________________________________________________________
44AliTRDsim::AliTRDsim():TObject()
45{
46 //
47 // AliTRDsim default constructor
48 //
49
fa5e892a 50 fSpectrum = 0;
d1b06c24 51 fSigma = 0;
fa5e892a 52
46d29e70 53 Init();
54
55}
56
57//_____________________________________________________________________________
58AliTRDsim::AliTRDsim(AliModule *mod, Int_t foil, Int_t gap)
59{
60 //
61 // AliTRDsim constructor. Takes the material properties of the radiator
62 // foils and the gas in the gaps from AliModule <mod>.
63 // The default number of foils is 100 with a thickness of 20 mu. The
64 // thickness of the gaps is 500 mu.
65 //
66
67 Float_t aFoil, zFoil, rhoFoil;
68 Float_t aGap, zGap, rhoGap;
69 Float_t rad, abs;
70 Char_t name[21];
71
fa5e892a 72 fSpectrum = 0;
d1b06c24 73 fSigma = 0;
fa5e892a 74
46d29e70 75 Init();
76
77 mod->AliGetMaterial(foil,name,aFoil,zFoil,rhoFoil,rad,abs);
78 mod->AliGetMaterial(gap ,name,aGap ,zGap ,rhoGap ,rad,abs);
79
80 fFoilDens = rhoFoil;
81 fFoilA = aFoil;
82 fFoilZ = zFoil;
83 fFoilOmega = Omega(fFoilDens,fFoilZ,fFoilA);
84
85 fGapDens = rhoGap;
86 fGapA = aGap;
87 fGapZ = zGap;
88 fGapOmega = Omega(fGapDens ,fGapZ ,fGapA );
89
90}
91
92//_____________________________________________________________________________
73ae7b59 93AliTRDsim::AliTRDsim(const AliTRDsim &s):TObject(s)
46d29e70 94{
95 //
96 // AliTRDsim copy constructor
97 //
98
99 ((AliTRDsim &) s).Copy(*this);
100
101}
102
103//_____________________________________________________________________________
104AliTRDsim::~AliTRDsim()
105{
106 //
107 // AliTRDsim destructor
108 //
109
5567246e 110 // if (fSpectrum) delete fSpectrum;
111 if (fSigma) delete [] fSigma;
46d29e70 112
113}
114
115//_____________________________________________________________________________
116AliTRDsim &AliTRDsim::operator=(const AliTRDsim &s)
117{
118 //
119 // Assignment operator
120 //
121
122 if (this != &s) ((AliTRDsim &) s).Copy(*this);
123 return *this;
124
125}
126
127//_____________________________________________________________________________
128void AliTRDsim::Copy(TObject &s)
129{
130 //
131 // Copy function
132 //
133
134 ((AliTRDsim &) s).fNFoils = fNFoils;
135 ((AliTRDsim &) s).fFoilThick = fFoilThick;
136 ((AliTRDsim &) s).fFoilDens = fFoilDens;
137 ((AliTRDsim &) s).fFoilOmega = fFoilOmega;
138 ((AliTRDsim &) s).fFoilZ = fFoilZ;
139 ((AliTRDsim &) s).fFoilA = fFoilA;
140 ((AliTRDsim &) s).fGapThick = fGapThick;
141 ((AliTRDsim &) s).fGapDens = fGapDens;
142 ((AliTRDsim &) s).fGapOmega = fGapOmega;
143 ((AliTRDsim &) s).fGapZ = fGapZ;
144 ((AliTRDsim &) s).fGapA = fGapA;
145 ((AliTRDsim &) s).fTemp = fTemp;
146 ((AliTRDsim &) s).fSpNBins = fSpNBins;
147 ((AliTRDsim &) s).fSpRange = fSpRange;
148 ((AliTRDsim &) s).fSpBinWidth = fSpBinWidth;
149 ((AliTRDsim &) s).fSpLower = fSpLower;
150 ((AliTRDsim &) s).fSpUpper = fSpUpper;
151
5567246e 152 if (((AliTRDsim &) s).fSigma) delete [] ((AliTRDsim &) s).fSigma;
46d29e70 153 ((AliTRDsim &) s).fSigma = new Double_t[fSpNBins];
154 for (Int_t iBin = 0; iBin < fSpNBins; iBin++) {
155 ((AliTRDsim &) s).fSigma[iBin] = fSigma[iBin];
156 }
157
158 fSpectrum->Copy(*((AliTRDsim &) s).fSpectrum);
159
160}
161
162//_____________________________________________________________________________
163void AliTRDsim::Init()
164{
165 //
166 // Initialization
db30bf0f 167 // The default radiator are 100 prolypropilene foils of 13 mu thickness
168 // with gaps of 60 mu filled with CO2.
46d29e70 169 //
170
171 fNFoils = 100;
172
db30bf0f 173 fFoilThick = 0.0013;
46d29e70 174 fFoilDens = 0.92;
175 fFoilZ = 5.28571;
176 fFoilA = 10.4286;
177 fFoilOmega = Omega(fFoilDens,fFoilZ,fFoilA);
178
db30bf0f 179 fGapThick = 0.0060;
46d29e70 180 fGapDens = 0.001977;
181 fGapZ = 7.45455;
182 fGapA = 14.9091;
183 fGapOmega = Omega(fGapDens ,fGapZ ,fGapA );
184
185 fTemp = 293.16;
186
187 fSpNBins = 200;
188 fSpRange = 100;
189 fSpBinWidth = fSpRange / fSpNBins;
190 fSpLower = 1.0 - 0.5 * fSpBinWidth;
191 fSpUpper = fSpLower + fSpRange;
192
193 if (fSpectrum) delete fSpectrum;
194 fSpectrum = new TH1D("TRspectrum","TR spectrum",fSpNBins,fSpLower,fSpUpper);
abaf1f1d 195 fSpectrum->SetDirectory(0);
46d29e70 196
197 // Set the sigma values
198 SetSigma();
199
200}
201
202//_____________________________________________________________________________
203Int_t AliTRDsim::CreatePhotons(Int_t pdg, Float_t p
204 , Int_t &nPhoton, Float_t *ePhoton)
205{
206 //
207 // Create TRD photons for a charged particle of type <pdg> with the total
208 // momentum <p>.
209 // Number of produced TR photons: <nPhoton>
210 // Energies of the produced TR photons: <ePhoton>
211 //
212
213 // PDG codes
214 const Int_t kPdgEle = 11;
215 const Int_t kPdgMuon = 13;
216 const Int_t kPdgPion = 211;
217 const Int_t kPdgKaon = 321;
218
219 Float_t mass = 0;
220 switch (TMath::Abs(pdg)) {
221 case kPdgEle:
222 mass = 5.11e-4;
223 break;
224 case kPdgMuon:
225 mass = 0.10566;
226 break;
227 case kPdgPion:
228 mass = 0.13957;
229 break;
230 case kPdgKaon:
231 mass = 0.4937;
232 break;
233 default:
234 return 0;
235 break;
236 };
237
238 // Calculate gamma
239 Double_t gamma = TMath::Sqrt(p*p + mass*mass) / mass;
240
241 // Calculate the TR photons
242 return TrPhotons(gamma, nPhoton, ePhoton);
243
244}
245
246//_____________________________________________________________________________
247Int_t AliTRDsim::TrPhotons(Double_t gamma, Int_t &nPhoton, Float_t *ePhoton)
248{
249 //
250 // Produces TR photons.
251 //
252
253 const Double_t kAlpha = 0.0072973;
254 const Int_t kSumMax = 10;
255
256 Double_t kappa = fGapThick / fFoilThick;
257
258 fSpectrum->Reset();
259
260 // The TR spectrum
261 Double_t stemp = 0;
262 for (Int_t iBin = 0; iBin < fSpNBins; iBin++) {
263
264 // keV -> eV
265 Double_t energyeV = (fSpBinWidth * iBin + 1.0) * 1e3;
266
267 Double_t csFoil = fFoilOmega / energyeV;
268 Double_t csGap = fGapOmega / energyeV;
269
270 Double_t rho1 = energyeV * fFoilThick * 1e4 * 2.5
271 * (1.0 / (gamma*gamma) + csFoil*csFoil);
272 Double_t rho2 = energyeV * fFoilThick * 1e4 * 2.5
273 * (1.0 / (gamma*gamma) + csGap *csGap);
274
275 // Calculate the sum
276 Double_t sum = 0;
277 for (Int_t iSum = 0; iSum < kSumMax; iSum++) {
278 Double_t tetan = (TMath::Pi() * 2.0 * (iSum+1) - (rho1 + kappa * rho2))
279 / (kappa + 1.0);
280 if (tetan < 0.0) tetan = 0.0;
281 Double_t aux = 1.0 / (rho1 + tetan) - 1.0 / (rho2 + tetan);
282 sum += tetan * (aux*aux) * (1.0 - TMath::Cos(rho1 + tetan));
283 }
284
285 // Absorbtion
286 Double_t conv = 1.0 - TMath::Exp(-fNFoils * fSigma[iBin]);
287
288 // eV -> keV
289 Float_t energykeV = energyeV * 0.001;
290
291 // dN / domega
292 Double_t wn = kAlpha * 4.0 / (fSigma[iBin] * (kappa + 1.0))
293 * conv * sum / energykeV;
294 fSpectrum->SetBinContent(iBin,wn);
295
296 stemp += wn;
297
298 }
299
300 // <nTR> (binsize corr.)
301 Float_t ntr = stemp * fSpBinWidth;
302 // Number of TR photons from Poisson distribution with mean <ntr>
303 nPhoton = gRandom->Poisson(ntr);
304 // Energy of the TR photons
305 for (Int_t iPhoton = 0; iPhoton < nPhoton; iPhoton++) {
306 ePhoton[iPhoton] = fSpectrum->GetRandom();
307 }
308
309 return 1;
310
311}
312
313//_____________________________________________________________________________
314void AliTRDsim::SetSigma()
315{
316 //
317 // Sets the absorbtion crosssection for the energies of the TR spectrum
318 //
319
5567246e 320 if (fSigma) delete [] fSigma;
46d29e70 321 fSigma = new Double_t[fSpNBins];
322 for (Int_t iBin = 0; iBin < fSpNBins; iBin++) {
323 Double_t energykeV = iBin * fSpBinWidth + 1.0;
324 fSigma[iBin] = Sigma(energykeV);
325 //printf("SetSigma(): iBin = %d fSigma %g\n",iBin,fSigma[iBin]);
326 }
327
328}
329
330//_____________________________________________________________________________
331Double_t AliTRDsim::Sigma(Double_t energykeV)
332{
333 //
334 // Calculates the absorbtion crosssection for a one-foil-one-gap-radiator
335 //
336
46d29e70 337 // keV -> MeV
338 Double_t energyMeV = energykeV * 0.001;
339 if (energyMeV >= 0.001) {
842287f2 340 return(GetMuPo(energyMeV) * fFoilDens * fFoilThick +
341 GetMuAi(energyMeV) * fGapDens * fGapThick * GetTemp());
46d29e70 342 }
343 else {
344 return 1e6;
345 }
346
347}
348
349//_____________________________________________________________________________
350Double_t AliTRDsim::GetMuPo(Double_t energyMeV)
351{
352 //
353 // Returns the photon absorbtion cross section for polypropylene
354 //
355
356 const Int_t kN = 36;
357
358 Double_t mu[kN] = { 1.894E+03, 5.999E+02, 2.593E+02
359 , 7.743E+01, 3.242E+01, 1.643E+01
360 , 9.432E+00, 3.975E+00, 2.088E+00
361 , 7.452E-01, 4.315E-01, 2.706E-01
362 , 2.275E-01, 2.084E-01, 1.970E-01
363 , 1.823E-01, 1.719E-01, 1.534E-01
364 , 1.402E-01, 1.217E-01, 1.089E-01
365 , 9.947E-02, 9.198E-02, 8.078E-02
366 , 7.262E-02, 6.495E-02, 5.910E-02
367 , 5.064E-02, 4.045E-02, 3.444E-02
368 , 3.045E-02, 2.760E-02, 2.383E-02
369 , 2.145E-02, 1.819E-02, 1.658E-02 };
370
371 Double_t en[kN] = { 1.000E-03, 1.500E-03, 2.000E-03
372 , 3.000E-03, 4.000E-03, 5.000E-03
373 , 6.000E-03, 8.000E-03, 1.000E-02
374 , 1.500E-02, 2.000E-02, 3.000E-02
375 , 4.000E-02, 5.000E-02, 6.000E-02
376 , 8.000E-02, 1.000E-01, 1.500E-01
377 , 2.000E-01, 3.000E-01, 4.000E-01
378 , 5.000E-01, 6.000E-01, 8.000E-01
379 , 1.000E+00, 1.250E+00, 1.500E+00
380 , 2.000E+00, 3.000E+00, 4.000E+00
381 , 5.000E+00, 6.000E+00, 8.000E+00
382 , 1.000E+01, 1.500E+01, 2.000E+01 };
383
384 return Interpolate(energyMeV,en,mu,kN);
385
386}
387
388//_____________________________________________________________________________
389Double_t AliTRDsim::GetMuCO(Double_t energyMeV)
390{
391 //
392 // Returns the photon absorbtion cross section for CO2
393 //
394
395 const Int_t kN = 36;
396
397 Double_t mu[kN] = { 0.39383E+04, 0.13166E+04, 0.58750E+03
398 , 0.18240E+03, 0.77996E+02, 0.40024E+02
399 , 0.23116E+02, 0.96997E+01, 0.49726E+01
400 , 0.15543E+01, 0.74915E+00, 0.34442E+00
401 , 0.24440E+00, 0.20589E+00, 0.18632E+00
402 , 0.16578E+00, 0.15394E+00, 0.13558E+00
403 , 0.12336E+00, 0.10678E+00, 0.95510E-01
404 , 0.87165E-01, 0.80587E-01, 0.70769E-01
405 , 0.63626E-01, 0.56894E-01, 0.51782E-01
406 , 0.44499E-01, 0.35839E-01, 0.30825E-01
407 , 0.27555E-01, 0.25269E-01, 0.22311E-01
408 , 0.20516E-01, 0.18184E-01, 0.17152E-01 };
409
410 Double_t en[kN] = { 0.10000E-02, 0.15000E-02, 0.20000E-02
411 , 0.30000E-02, 0.40000E-02, 0.50000E-02
412 , 0.60000E-02, 0.80000E-02, 0.10000E-01
413 , 0.15000E-01, 0.20000E-01, 0.30000E-01
414 , 0.40000E-01, 0.50000E-01, 0.60000E-01
415 , 0.80000E-01, 0.10000E+00, 0.15000E+00
416 , 0.20000E+00, 0.30000E+00, 0.40000E+00
417 , 0.50000E+00, 0.60000E+00, 0.80000E+00
418 , 0.10000E+01, 0.12500E+01, 0.15000E+01
419 , 0.20000E+01, 0.30000E+01, 0.40000E+01
420 , 0.50000E+01, 0.60000E+01, 0.80000E+01
421 , 0.10000E+02, 0.15000E+02, 0.20000E+02 };
422
423 return Interpolate(energyMeV,en,mu,kN);
424
425}
426
427//_____________________________________________________________________________
428Double_t AliTRDsim::GetMuXe(Double_t energyMeV)
429{
430 //
431 // Returns the photon absorbtion cross section for xenon
432 //
433
434 const Int_t kN = 48;
435
436 Double_t mu[kN] = { 9.413E+03, 8.151E+03, 7.035E+03
437 , 7.338E+03, 4.085E+03, 2.088E+03
438 , 7.780E+02, 3.787E+02, 2.408E+02
439 , 6.941E+02, 6.392E+02, 6.044E+02
440 , 8.181E+02, 7.579E+02, 6.991E+02
441 , 8.064E+02, 6.376E+02, 3.032E+02
442 , 1.690E+02, 5.743E+01, 2.652E+01
443 , 8.930E+00, 6.129E+00, 3.316E+01
444 , 2.270E+01, 1.272E+01, 7.825E+00
445 , 3.633E+00, 2.011E+00, 7.202E-01
446 , 3.760E-01, 1.797E-01, 1.223E-01
447 , 9.699E-02, 8.281E-02, 6.696E-02
448 , 5.785E-02, 5.054E-02, 4.594E-02
449 , 4.078E-02, 3.681E-02, 3.577E-02
450 , 3.583E-02, 3.634E-02, 3.797E-02
451 , 3.987E-02, 4.445E-02, 4.815E-02 };
452
453 Double_t en[kN] = { 1.00000E-03, 1.07191E-03, 1.14900E-03
454 , 1.14900E-03, 1.50000E-03, 2.00000E-03
455 , 3.00000E-03, 4.00000E-03, 4.78220E-03
456 , 4.78220E-03, 5.00000E-03, 5.10370E-03
457 , 5.10370E-03, 5.27536E-03, 5.45280E-03
458 , 5.45280E-03, 6.00000E-03, 8.00000E-03
459 , 1.00000E-02, 1.50000E-02, 2.00000E-02
460 , 3.00000E-02, 3.45614E-02, 3.45614E-02
461 , 4.00000E-02, 5.00000E-02, 6.00000E-02
462 , 8.00000E-02, 1.00000E-01, 1.50000E-01
463 , 2.00000E-01, 3.00000E-01, 4.00000E-01
464 , 5.00000E-01, 6.00000E-01, 8.00000E-01
465 , 1.00000E+00, 1.25000E+00, 1.50000E+00
466 , 2.00000E+00, 3.00000E+00, 4.00000E+00
467 , 5.00000E+00, 6.00000E+00, 8.00000E+00
468 , 1.00000E+01, 1.50000E+01, 2.00000E+01 };
469
470 return Interpolate(energyMeV,en,mu,kN);
471
472}
473
474//_____________________________________________________________________________
475Double_t AliTRDsim::GetMuBu(Double_t energyMeV)
476{
477 //
478 // Returns the photon absorbtion cross section for isobutane
479 //
480
481 const Int_t kN = 36;
482
483 Double_t mu[kN] = { 0.38846E+03, 0.12291E+03, 0.53225E+02
484 , 0.16091E+02, 0.69114E+01, 0.36541E+01
485 , 0.22282E+01, 0.11149E+01, 0.72887E+00
486 , 0.45053E+00, 0.38167E+00, 0.33920E+00
487 , 0.32155E+00, 0.30949E+00, 0.29960E+00
488 , 0.28317E+00, 0.26937E+00, 0.24228E+00
489 , 0.22190E+00, 0.19289E+00, 0.17288E+00
490 , 0.15789E+00, 0.14602E+00, 0.12829E+00
491 , 0.11533E+00, 0.10310E+00, 0.93790E-01
492 , 0.80117E-01, 0.63330E-01, 0.53229E-01
493 , 0.46390E-01, 0.41425E-01, 0.34668E-01
494 , 0.30267E-01, 0.23910E-01, 0.20509E-01 };
495
496 Double_t en[kN] = { 0.10000E-02, 0.15000E-02, 0.20000E-02
497 , 0.30000E-02, 0.40000E-02, 0.50000E-02
498 , 0.60000E-02, 0.80000E-02, 0.10000E-01
499 , 0.15000E-01, 0.20000E-01, 0.30000E-01
500 , 0.40000E-01, 0.50000E-01, 0.60000E-01
501 , 0.80000E-01, 0.10000E+00, 0.15000E+00
502 , 0.20000E+00, 0.30000E+00, 0.40000E+00
503 , 0.50000E+00, 0.60000E+00, 0.80000E+00
504 , 0.10000E+01, 0.12500E+01, 0.15000E+01
505 , 0.20000E+01, 0.30000E+01, 0.40000E+01
506 , 0.50000E+01, 0.60000E+01, 0.80000E+01
507 , 0.10000E+02, 0.15000E+02, 0.20000E+02 };
508
509 return Interpolate(energyMeV,en,mu,kN);
510
511}
512
513//_____________________________________________________________________________
514Double_t AliTRDsim::GetMuMy(Double_t energyMeV)
515{
516 //
517 // Returns the photon absorbtion cross section for mylar
518 //
519
520 const Int_t kN = 36;
521
522 Double_t mu[kN] = { 2.911E+03, 9.536E+02, 4.206E+02
523 , 1.288E+02, 5.466E+01, 2.792E+01
524 , 1.608E+01, 6.750E+00, 3.481E+00
525 , 1.132E+00, 5.798E-01, 3.009E-01
526 , 2.304E-01, 2.020E-01, 1.868E-01
527 , 1.695E-01, 1.586E-01, 1.406E-01
528 , 1.282E-01, 1.111E-01, 9.947E-02
529 , 9.079E-02, 8.395E-02, 7.372E-02
530 , 6.628E-02, 5.927E-02, 5.395E-02
531 , 4.630E-02, 3.715E-02, 3.181E-02
532 , 2.829E-02, 2.582E-02, 2.257E-02
533 , 2.057E-02, 1.789E-02, 1.664E-02 };
534
535 Double_t en[kN] = { 1.00000E-03, 1.50000E-03, 2.00000E-03
536 , 3.00000E-03, 4.00000E-03, 5.00000E-03
537 , 6.00000E-03, 8.00000E-03, 1.00000E-02
538 , 1.50000E-02, 2.00000E-02, 3.00000E-02
539 , 4.00000E-02, 5.00000E-02, 6.00000E-02
540 , 8.00000E-02, 1.00000E-01, 1.50000E-01
541 , 2.00000E-01, 3.00000E-01, 4.00000E-01
542 , 5.00000E-01, 6.00000E-01, 8.00000E-01
543 , 1.00000E+00, 1.25000E+00, 1.50000E+00
544 , 2.00000E+00, 3.00000E+00, 4.00000E+00
545 , 5.00000E+00, 6.00000E+00, 8.00000E+00
546 , 1.00000E+01, 1.50000E+01, 2.00000E+01 };
547
548 return Interpolate(energyMeV,en,mu,kN);
549
550}
551
552//_____________________________________________________________________________
553Double_t AliTRDsim::GetMuN2(Double_t energyMeV)
554{
555 //
556 // Returns the photon absorbtion cross section for nitrogen
557 //
558
559 const Int_t kN = 36;
560
561 Double_t mu[kN] = { 3.311E+03, 1.083E+03, 4.769E+02
562 , 1.456E+02, 6.166E+01, 3.144E+01
563 , 1.809E+01, 7.562E+00, 3.879E+00
564 , 1.236E+00, 6.178E-01, 3.066E-01
565 , 2.288E-01, 1.980E-01, 1.817E-01
566 , 1.639E-01, 1.529E-01, 1.353E-01
567 , 1.233E-01, 1.068E-01, 9.557E-02
568 , 8.719E-02, 8.063E-02, 7.081E-02
569 , 6.364E-02, 5.693E-02, 5.180E-02
570 , 4.450E-02, 3.579E-02, 3.073E-02
571 , 2.742E-02, 2.511E-02, 2.209E-02
572 , 2.024E-02, 1.782E-02, 1.673E-02 };
573
574 Double_t en[kN] = { 1.00000E-03, 1.50000E-03, 2.00000E-03
575 , 3.00000E-03, 4.00000E-03, 5.00000E-03
576 , 6.00000E-03, 8.00000E-03, 1.00000E-02
577 , 1.50000E-02, 2.00000E-02, 3.00000E-02
578 , 4.00000E-02, 5.00000E-02, 6.00000E-02
579 , 8.00000E-02, 1.00000E-01, 1.50000E-01
580 , 2.00000E-01, 3.00000E-01, 4.00000E-01
581 , 5.00000E-01, 6.00000E-01, 8.00000E-01
582 , 1.00000E+00, 1.25000E+00, 1.50000E+00
583 , 2.00000E+00, 3.00000E+00, 4.00000E+00
584 , 5.00000E+00, 6.00000E+00, 8.00000E+00
585 , 1.00000E+01, 1.50000E+01, 2.00000E+01 };
586
587 return Interpolate(energyMeV,en,mu,kN);
588
589}
590
591//_____________________________________________________________________________
592Double_t AliTRDsim::GetMuO2(Double_t energyMeV)
593{
594 //
595 // Returns the photon absorbtion cross section for oxygen
596 //
597
598 const Int_t kN = 36;
599
600 Double_t mu[kN] = { 4.590E+03, 1.549E+03, 6.949E+02
601 , 2.171E+02, 9.315E+01, 4.790E+01
602 , 2.770E+01, 1.163E+01, 5.952E+00
603 , 1.836E+00, 8.651E-01, 3.779E-01
604 , 2.585E-01, 2.132E-01, 1.907E-01
605 , 1.678E-01, 1.551E-01, 1.361E-01
606 , 1.237E-01, 1.070E-01, 9.566E-02
607 , 8.729E-02, 8.070E-02, 7.087E-02
608 , 6.372E-02, 5.697E-02, 5.185E-02
609 , 4.459E-02, 3.597E-02, 3.100E-02
610 , 2.777E-02, 2.552E-02, 2.263E-02
611 , 2.089E-02, 1.866E-02, 1.770E-02 };
612
613 Double_t en[kN] = { 1.00000E-03, 1.50000E-03, 2.00000E-03
614 , 3.00000E-03, 4.00000E-03, 5.00000E-03
615 , 6.00000E-03, 8.00000E-03, 1.00000E-02
616 , 1.50000E-02, 2.00000E-02, 3.00000E-02
617 , 4.00000E-02, 5.00000E-02, 6.00000E-02
618 , 8.00000E-02, 1.00000E-01, 1.50000E-01
619 , 2.00000E-01, 3.00000E-01, 4.00000E-01
620 , 5.00000E-01, 6.00000E-01, 8.00000E-01
621 , 1.00000E+00, 1.25000E+00, 1.50000E+00
622 , 2.00000E+00, 3.00000E+00, 4.00000E+00
623 , 5.00000E+00, 6.00000E+00, 8.00000E+00
624 , 1.00000E+01, 1.50000E+01, 2.00000E+01 };
625
626 return Interpolate(energyMeV,en,mu,kN);
627
628}
629
630//_____________________________________________________________________________
631Double_t AliTRDsim::GetMuHe(Double_t energyMeV)
632{
633 //
634 // Returns the photon absorbtion cross section for helium
635 //
636
637 const Int_t kN = 36;
638
639 Double_t mu[kN] = { 6.084E+01, 1.676E+01, 6.863E+00
640 , 2.007E+00, 9.329E-01, 5.766E-01
641 , 4.195E-01, 2.933E-01, 2.476E-01
642 , 2.092E-01, 1.960E-01, 1.838E-01
643 , 1.763E-01, 1.703E-01, 1.651E-01
644 , 1.562E-01, 1.486E-01, 1.336E-01
645 , 1.224E-01, 1.064E-01, 9.535E-02
646 , 8.707E-02, 8.054E-02, 7.076E-02
647 , 6.362E-02, 5.688E-02, 5.173E-02
648 , 4.422E-02, 3.503E-02, 2.949E-02
649 , 2.577E-02, 2.307E-02, 1.940E-02
650 , 1.703E-02, 1.363E-02, 1.183E-02 };
651
652 Double_t en[kN] = { 1.00000E-03, 1.50000E-03, 2.00000E-03
653 , 3.00000E-03, 4.00000E-03, 5.00000E-03
654 , 6.00000E-03, 8.00000E-03, 1.00000E-02
655 , 1.50000E-02, 2.00000E-02, 3.00000E-02
656 , 4.00000E-02, 5.00000E-02, 6.00000E-02
657 , 8.00000E-02, 1.00000E-01, 1.50000E-01
658 , 2.00000E-01, 3.00000E-01, 4.00000E-01
659 , 5.00000E-01, 6.00000E-01, 8.00000E-01
660 , 1.00000E+00, 1.25000E+00, 1.50000E+00
661 , 2.00000E+00, 3.00000E+00, 4.00000E+00
662 , 5.00000E+00, 6.00000E+00, 8.00000E+00
663 , 1.00000E+01, 1.50000E+01, 2.00000E+01 };
664
665 return Interpolate(energyMeV,en,mu,kN);
666
667}
668
842287f2 669//_____________________________________________________________________________
670Double_t AliTRDsim::GetMuAi(Double_t energyMeV)
671{
672 //
673 // Returns the photon absorbtion cross section for air
674 // Implemented by Oliver Busch
675 //
676
677 const Int_t kN = 38;
678
679 Double_t mu[kN] = { 0.35854E+04, 0.11841E+04, 0.52458E+03,
680 0.16143E+03, 0.14250E+03, 0.15722E+03,
681 0.77538E+02, 0.40099E+02, 0.23313E+02,
682 0.98816E+01, 0.51000E+01, 0.16079E+01,
683 0.77536E+00, 0.35282E+00, 0.24790E+00,
684 0.20750E+00, 0.18703E+00, 0.16589E+00,
685 0.15375E+00, 0.13530E+00, 0.12311E+00,
686 0.10654E+00, 0.95297E-01, 0.86939E-01,
687 0.80390E-01, 0.70596E-01, 0.63452E-01,
688 0.56754E-01, 0.51644E-01, 0.44382E-01,
689 0.35733E-01, 0.30721E-01, 0.27450E-01,
690 0.25171E-01, 0.22205E-01, 0.20399E-01,
691 0.18053E-01, 0.18057E-01 };
692
693
694
695 Double_t en[kN] = { 0.10000E-02, 0.15000E-02, 0.20000E-02,
696 0.30000E-02, 0.32029E-02, 0.32029E-02,
697 0.40000E-02, 0.50000E-02, 0.60000E-02,
698 0.80000E-02, 0.10000E-01, 0.15000E-01,
699 0.20000E-01, 0.30000E-01, 0.40000E-01,
700 0.50000E-01, 0.60000E-01, 0.80000E-01,
701 0.10000E+00, 0.15000E+00, 0.20000E+00,
702 0.30000E+00, 0.40000E+00, 0.50000E+00,
703 0.60000E+00, 0.80000E+00, 0.10000E+01,
704 0.12500E+01, 0.15000E+01, 0.20000E+01,
705 0.30000E+01, 0.40000E+01, 0.50000E+01,
706 0.60000E+01, 0.80000E+01, 0.10000E+02,
707 0.15000E+02, 0.20000E+02 };
708
709 return Interpolate(energyMeV,en,mu,kN);
710
711}
712
46d29e70 713//_____________________________________________________________________________
714Double_t AliTRDsim::Interpolate(Double_t energyMeV
715 , Double_t *en, Double_t *mu, Int_t n)
716{
717 //
718 // Interpolates the photon absorbtion cross section
719 // for a given energy <energyMeV>.
720 //
721
722 Double_t de = 0;
723 Int_t index = 0;
724 Int_t istat = Locate(en,n,energyMeV,index,de);
725 if (istat == 0) {
726 return (mu[index] - de * (mu[index] - mu[index+1])
727 / (en[index+1] - en[index] ));
728 }
729 else {
730 return 0.0;
731 }
732
733}
734
735//_____________________________________________________________________________
736Int_t AliTRDsim::Locate(Double_t *xv, Int_t n, Double_t xval
737 , Int_t &kl, Double_t &dx)
738{
739 //
740 // Locates a point (xval) in a 1-dim grid (xv(n))
741 //
742
743 if (xval >= xv[n-1]) return 1;
744 if (xval < xv[0]) return -1;
745
746 Int_t km;
747 Int_t kh = n - 1;
748
749 kl = 0;
750 while (kh - kl > 1) {
751 if (xval < xv[km = (kl+kh)/2]) kh = km;
752 else kl = km;
753 }
754 if (xval < xv[kl] || xval > xv[kl+1] || kl >= n-1) {
755 printf("Locate failed xv[%d] %f xval %f xv[%d] %f!!!\n"
756 ,kl,xv[kl],xval,kl+1,xv[kl+1]);
757 exit(1);
758 }
759
760 dx = xval - xv[kl];
761
762 return 0;
763
764}