2 /**************************************************************************
3 * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
5 * Author: The ALICE Off-line Project. *
6 * Contributors are mentioned in the code where appropriate. *
8 * Permission to use, copy, modify and distribute this software and its *
9 * documentation strictly for non-commercial purposes is hereby granted *
10 * without fee, provided that the above copyright notice appears in all *
11 * copies and that both the copyright notice and this permission notice *
12 * appear in the supporting documentation. The authors make no claims *
13 * about the suitability of this software for any purpose. It is *
14 * provided "as is" without express or implied warranty. *
15 **************************************************************************/
19 ///////////////////////////////////////////////////////////////////////////////
21 // TRD simulation - multimodule (regular rad.) //
22 // after: M. CASTELLANO et al., COMP. PHYS. COMM. 51 (1988) 431 //
23 // + COMP. PHYS. COMM. 61 (1990) 395 //
25 // 17.07.1998 - A.Andronic //
26 // 08.12.1998 - simplified version //
27 // 11.07.2000 - Adapted code to aliroot environment (C.Blume) //
28 // 04.06.2004 - Momentum dependent parameters implemented (CBL) //
30 ///////////////////////////////////////////////////////////////////////////////
37 #include <TParticle.h>
39 #include "AliModule.h"
41 #include "AliTRDsim.h"
45 //_____________________________________________________________________________
46 AliTRDsim::AliTRDsim():TObject()
49 // AliTRDsim default constructor
61 //_____________________________________________________________________________
62 AliTRDsim::AliTRDsim(AliModule *mod, Int_t foil, Int_t gap)
65 // AliTRDsim constructor. Takes the material properties of the radiator
66 // foils and the gas in the gaps from AliModule <mod>.
67 // The default number of foils is 100 with a thickness of 20 mu. The
68 // thickness of the gaps is 500 mu.
71 Float_t aFoil, zFoil, rhoFoil;
72 Float_t aGap, zGap, rhoGap;
83 mod->AliGetMaterial(foil,name,aFoil,zFoil,rhoFoil,rad,abs);
84 mod->AliGetMaterial(gap ,name,aGap ,zGap ,rhoGap ,rad,abs);
89 fFoilOmega = Omega(fFoilDens,fFoilZ,fFoilA);
94 fGapOmega = Omega(fGapDens ,fGapZ ,fGapA );
98 //_____________________________________________________________________________
99 AliTRDsim::AliTRDsim(const AliTRDsim &s):TObject(s)
102 // AliTRDsim copy constructor
105 ((AliTRDsim &) s).Copy(*this);
109 //_____________________________________________________________________________
110 AliTRDsim::~AliTRDsim()
113 // AliTRDsim destructor
116 // if (fSpectrum) delete fSpectrum;
117 if (fSigma) delete [] fSigma;
118 if (fNFoils) delete [] fNFoils;
119 if (fNFoilsUp) delete [] fNFoilsUp;
123 //_____________________________________________________________________________
124 AliTRDsim &AliTRDsim::operator=(const AliTRDsim &s)
127 // Assignment operator
130 if (this != &s) ((AliTRDsim &) s).Copy(*this);
135 //_____________________________________________________________________________
136 void AliTRDsim::Copy(TObject &s) const
142 ((AliTRDsim &) s).fFoilThick = fFoilThick;
143 ((AliTRDsim &) s).fFoilDens = fFoilDens;
144 ((AliTRDsim &) s).fFoilOmega = fFoilOmega;
145 ((AliTRDsim &) s).fFoilZ = fFoilZ;
146 ((AliTRDsim &) s).fFoilA = fFoilA;
147 ((AliTRDsim &) s).fGapThick = fGapThick;
148 ((AliTRDsim &) s).fGapDens = fGapDens;
149 ((AliTRDsim &) s).fGapOmega = fGapOmega;
150 ((AliTRDsim &) s).fGapZ = fGapZ;
151 ((AliTRDsim &) s).fGapA = fGapA;
152 ((AliTRDsim &) s).fTemp = fTemp;
153 ((AliTRDsim &) s).fSpNBins = fSpNBins;
154 ((AliTRDsim &) s).fSpRange = fSpRange;
155 ((AliTRDsim &) s).fSpBinWidth = fSpBinWidth;
156 ((AliTRDsim &) s).fSpLower = fSpLower;
157 ((AliTRDsim &) s).fSpUpper = fSpUpper;
159 if (((AliTRDsim &) s).fNFoils) delete [] ((AliTRDsim &) s).fNFoils;
160 ((AliTRDsim &) s).fNFoils = new Int_t[fNFoilsDim];
161 for (Int_t iFoil = 0; iFoil < fNFoilsDim; iFoil++) {
162 ((AliTRDsim &) s).fNFoils[iFoil] = fNFoils[iFoil];
165 if (((AliTRDsim &) s).fNFoilsUp) delete [] ((AliTRDsim &) s).fNFoilsUp;
166 ((AliTRDsim &) s).fNFoilsUp = new Double_t[fNFoilsDim];
167 for (Int_t iFoil = 0; iFoil < fNFoilsDim; iFoil++) {
168 ((AliTRDsim &) s).fNFoilsUp[iFoil] = fNFoilsUp[iFoil];
171 if (((AliTRDsim &) s).fSigma) delete [] ((AliTRDsim &) s).fSigma;
172 ((AliTRDsim &) s).fSigma = new Double_t[fSpNBins];
173 for (Int_t iBin = 0; iBin < fSpNBins; iBin++) {
174 ((AliTRDsim &) s).fSigma[iBin] = fSigma[iBin];
177 fSpectrum->Copy(*((AliTRDsim &) s).fSpectrum);
181 //_____________________________________________________________________________
182 void AliTRDsim::Init()
186 // The default radiator are prolypropilene foils of 10 mu thickness
187 // with gaps of 80 mu filled with N2.
192 if (fNFoils) delete [] fNFoils;
193 fNFoils = new Int_t[fNFoilsDim];
195 fNFoils[1] = 225; //250;
196 fNFoils[2] = 275; //310;
197 fNFoils[3] = 305; //380;
198 fNFoils[4] = 325; //430;
199 fNFoils[5] = 340; //490;
200 fNFoils[6] = 350; //550;
202 if (fNFoilsUp) delete [] fNFoilsUp;
203 fNFoilsUp = new Double_t[fNFoilsDim];
210 fNFoilsUp[6] = 10000.0;
216 fFoilOmega = Omega(fFoilDens,fFoilZ,fFoilA);
222 fGapOmega = Omega(fGapDens ,fGapZ ,fGapA );
228 fSpBinWidth = fSpRange / fSpNBins;
229 fSpLower = 1.0 - 0.5 * fSpBinWidth;
230 fSpUpper = fSpLower + fSpRange;
232 if (fSpectrum) delete fSpectrum;
233 fSpectrum = new TH1D("TRspectrum","TR spectrum",fSpNBins,fSpLower,fSpUpper);
234 fSpectrum->SetDirectory(0);
236 // Set the sigma values
241 //_____________________________________________________________________________
242 Int_t AliTRDsim::CreatePhotons(Int_t pdg, Float_t p
243 , Int_t &nPhoton, Float_t *ePhoton)
246 // Create TRD photons for a charged particle of type <pdg> with the total
248 // Number of produced TR photons: <nPhoton>
249 // Energies of the produced TR photons: <ePhoton>
253 const Int_t kPdgEle = 11;
254 const Int_t kPdgMuon = 13;
255 const Int_t kPdgPion = 211;
256 const Int_t kPdgKaon = 321;
259 switch (TMath::Abs(pdg)) {
277 // Calculate the TR photons
278 return TrPhotons(p, mass, nPhoton, ePhoton);
282 //_____________________________________________________________________________
283 Int_t AliTRDsim::TrPhotons(Float_t p, Float_t mass
284 , Int_t &nPhoton, Float_t *ePhoton)
287 // Produces TR photons.
290 const Double_t kAlpha = 0.0072973;
291 const Int_t kSumMax = 30;
293 Double_t tau = fGapThick / fFoilThick;
296 Double_t gamma = TMath::Sqrt(p*p + mass*mass) / mass;
298 // Select the number of foils corresponding to momentum
299 Int_t foils = SelectNFoils(p);
304 Double_t csi1,csi2,rho1,rho2;
305 Double_t fSigma,Sum,Nequ,theta_n,aux;
306 Double_t energyeV, energykeV;
307 for (Int_t iBin = 1; iBin <= fSpNBins; iBin++) {
308 energykeV = fSpectrum->GetBinCenter(iBin);
309 energyeV = energykeV * 1.e3;
311 fSigma = Sigma(energykeV);
313 csi1 = fFoilOmega / energyeV;
314 csi2 = fGapOmega / energyeV;
316 rho1 = 2.5 * energyeV * fFoilThick * 1.E4
317 * (1. / (gamma*gamma) + csi1*csi1);
318 rho2 = 2.5 * energyeV * fFoilThick * 1.E4
319 * (1.0 / (gamma*gamma) + csi2 *csi2);
323 for (Int_t n = 1; n <= kSumMax; n++) {
324 theta_n = (TMath::Pi() * 2.0 * n - (rho1 + tau * rho2)) / (1.+ tau);
325 if (theta_n < 0.) theta_n = 0.0;
326 aux = 1. / (rho1 + theta_n) - 1. / (rho2 + theta_n);
327 Sum += theta_n * (aux*aux) * (1.0 - TMath::Cos(rho1 + theta_n));
330 // Equivalent number of foils
331 Nequ = (1. - TMath::Exp(-foils * fSigma)) / (1.- TMath::Exp(-fSigma));
335 fSpectrum->SetBinContent(iBin,4. * kAlpha * Nequ * Sum / (energykeV * (1. + tau)));
338 // <nTR> (binsize corr.)
339 Float_t ntr = fSpBinWidth*fSpectrum->Integral();
340 // Number of TR photons from Poisson distribution with mean <ntr>
341 nPhoton = gRandom->Poisson(ntr);
342 // Energy of the TR photons
343 for (Int_t iPhoton = 0; iPhoton < nPhoton; iPhoton++) {
344 ePhoton[iPhoton] = fSpectrum->GetRandom();
351 //_____________________________________________________________________________
352 void AliTRDsim::SetSigma()
355 // Sets the absorbtion crosssection for the energies of the TR spectrum
358 if (fSigma) delete [] fSigma;
359 fSigma = new Double_t[fSpNBins];
360 for (Int_t iBin = 0; iBin < fSpNBins; iBin++) {
361 Double_t energykeV = iBin * fSpBinWidth + 1.0;
362 fSigma[iBin] = Sigma(energykeV);
363 //printf("SetSigma(): iBin = %d fSigma %g\n",iBin,fSigma[iBin]);
368 //_____________________________________________________________________________
369 Double_t AliTRDsim::Sigma(Double_t energykeV)
372 // Calculates the absorbtion crosssection for a one-foil-one-gap-radiator
376 Double_t energyMeV = energykeV * 0.001;
377 if (energyMeV >= 0.001) {
378 return(GetMuPo(energyMeV) * fFoilDens * fFoilThick +
379 GetMuAi(energyMeV) * fGapDens * fGapThick * GetTemp());
387 //_____________________________________________________________________________
388 Double_t AliTRDsim::GetMuPo(Double_t energyMeV)
391 // Returns the photon absorbtion cross section for polypropylene
396 Double_t mu[kN] = { 1.894E+03, 5.999E+02, 2.593E+02
397 , 7.743E+01, 3.242E+01, 1.643E+01
398 , 9.432E+00, 3.975E+00, 2.088E+00
399 , 7.452E-01, 4.315E-01, 2.706E-01
400 , 2.275E-01, 2.084E-01, 1.970E-01
401 , 1.823E-01, 1.719E-01, 1.534E-01
402 , 1.402E-01, 1.217E-01, 1.089E-01
403 , 9.947E-02, 9.198E-02, 8.078E-02
404 , 7.262E-02, 6.495E-02, 5.910E-02
405 , 5.064E-02, 4.045E-02, 3.444E-02
406 , 3.045E-02, 2.760E-02, 2.383E-02
407 , 2.145E-02, 1.819E-02, 1.658E-02 };
409 Double_t en[kN] = { 1.000E-03, 1.500E-03, 2.000E-03
410 , 3.000E-03, 4.000E-03, 5.000E-03
411 , 6.000E-03, 8.000E-03, 1.000E-02
412 , 1.500E-02, 2.000E-02, 3.000E-02
413 , 4.000E-02, 5.000E-02, 6.000E-02
414 , 8.000E-02, 1.000E-01, 1.500E-01
415 , 2.000E-01, 3.000E-01, 4.000E-01
416 , 5.000E-01, 6.000E-01, 8.000E-01
417 , 1.000E+00, 1.250E+00, 1.500E+00
418 , 2.000E+00, 3.000E+00, 4.000E+00
419 , 5.000E+00, 6.000E+00, 8.000E+00
420 , 1.000E+01, 1.500E+01, 2.000E+01 };
422 return Interpolate(energyMeV,en,mu,kN);
426 //_____________________________________________________________________________
427 Double_t AliTRDsim::GetMuCO(Double_t energyMeV)
430 // Returns the photon absorbtion cross section for CO2
435 Double_t mu[kN] = { 0.39383E+04, 0.13166E+04, 0.58750E+03
436 , 0.18240E+03, 0.77996E+02, 0.40024E+02
437 , 0.23116E+02, 0.96997E+01, 0.49726E+01
438 , 0.15543E+01, 0.74915E+00, 0.34442E+00
439 , 0.24440E+00, 0.20589E+00, 0.18632E+00
440 , 0.16578E+00, 0.15394E+00, 0.13558E+00
441 , 0.12336E+00, 0.10678E+00, 0.95510E-01
442 , 0.87165E-01, 0.80587E-01, 0.70769E-01
443 , 0.63626E-01, 0.56894E-01, 0.51782E-01
444 , 0.44499E-01, 0.35839E-01, 0.30825E-01
445 , 0.27555E-01, 0.25269E-01, 0.22311E-01
446 , 0.20516E-01, 0.18184E-01, 0.17152E-01 };
448 Double_t en[kN] = { 0.10000E-02, 0.15000E-02, 0.20000E-02
449 , 0.30000E-02, 0.40000E-02, 0.50000E-02
450 , 0.60000E-02, 0.80000E-02, 0.10000E-01
451 , 0.15000E-01, 0.20000E-01, 0.30000E-01
452 , 0.40000E-01, 0.50000E-01, 0.60000E-01
453 , 0.80000E-01, 0.10000E+00, 0.15000E+00
454 , 0.20000E+00, 0.30000E+00, 0.40000E+00
455 , 0.50000E+00, 0.60000E+00, 0.80000E+00
456 , 0.10000E+01, 0.12500E+01, 0.15000E+01
457 , 0.20000E+01, 0.30000E+01, 0.40000E+01
458 , 0.50000E+01, 0.60000E+01, 0.80000E+01
459 , 0.10000E+02, 0.15000E+02, 0.20000E+02 };
461 return Interpolate(energyMeV,en,mu,kN);
465 //_____________________________________________________________________________
466 Double_t AliTRDsim::GetMuXe(Double_t energyMeV)
469 // Returns the photon absorbtion cross section for xenon
474 Double_t mu[kN] = { 9.413E+03, 8.151E+03, 7.035E+03
475 , 7.338E+03, 4.085E+03, 2.088E+03
476 , 7.780E+02, 3.787E+02, 2.408E+02
477 , 6.941E+02, 6.392E+02, 6.044E+02
478 , 8.181E+02, 7.579E+02, 6.991E+02
479 , 8.064E+02, 6.376E+02, 3.032E+02
480 , 1.690E+02, 5.743E+01, 2.652E+01
481 , 8.930E+00, 6.129E+00, 3.316E+01
482 , 2.270E+01, 1.272E+01, 7.825E+00
483 , 3.633E+00, 2.011E+00, 7.202E-01
484 , 3.760E-01, 1.797E-01, 1.223E-01
485 , 9.699E-02, 8.281E-02, 6.696E-02
486 , 5.785E-02, 5.054E-02, 4.594E-02
487 , 4.078E-02, 3.681E-02, 3.577E-02
488 , 3.583E-02, 3.634E-02, 3.797E-02
489 , 3.987E-02, 4.445E-02, 4.815E-02 };
491 Double_t en[kN] = { 1.00000E-03, 1.07191E-03, 1.14900E-03
492 , 1.14900E-03, 1.50000E-03, 2.00000E-03
493 , 3.00000E-03, 4.00000E-03, 4.78220E-03
494 , 4.78220E-03, 5.00000E-03, 5.10370E-03
495 , 5.10370E-03, 5.27536E-03, 5.45280E-03
496 , 5.45280E-03, 6.00000E-03, 8.00000E-03
497 , 1.00000E-02, 1.50000E-02, 2.00000E-02
498 , 3.00000E-02, 3.45614E-02, 3.45614E-02
499 , 4.00000E-02, 5.00000E-02, 6.00000E-02
500 , 8.00000E-02, 1.00000E-01, 1.50000E-01
501 , 2.00000E-01, 3.00000E-01, 4.00000E-01
502 , 5.00000E-01, 6.00000E-01, 8.00000E-01
503 , 1.00000E+00, 1.25000E+00, 1.50000E+00
504 , 2.00000E+00, 3.00000E+00, 4.00000E+00
505 , 5.00000E+00, 6.00000E+00, 8.00000E+00
506 , 1.00000E+01, 1.50000E+01, 2.00000E+01 };
508 return Interpolate(energyMeV,en,mu,kN);
512 //_____________________________________________________________________________
513 Double_t AliTRDsim::GetMuBu(Double_t energyMeV)
516 // Returns the photon absorbtion cross section for isobutane
521 Double_t mu[kN] = { 0.38846E+03, 0.12291E+03, 0.53225E+02
522 , 0.16091E+02, 0.69114E+01, 0.36541E+01
523 , 0.22282E+01, 0.11149E+01, 0.72887E+00
524 , 0.45053E+00, 0.38167E+00, 0.33920E+00
525 , 0.32155E+00, 0.30949E+00, 0.29960E+00
526 , 0.28317E+00, 0.26937E+00, 0.24228E+00
527 , 0.22190E+00, 0.19289E+00, 0.17288E+00
528 , 0.15789E+00, 0.14602E+00, 0.12829E+00
529 , 0.11533E+00, 0.10310E+00, 0.93790E-01
530 , 0.80117E-01, 0.63330E-01, 0.53229E-01
531 , 0.46390E-01, 0.41425E-01, 0.34668E-01
532 , 0.30267E-01, 0.23910E-01, 0.20509E-01 };
534 Double_t en[kN] = { 0.10000E-02, 0.15000E-02, 0.20000E-02
535 , 0.30000E-02, 0.40000E-02, 0.50000E-02
536 , 0.60000E-02, 0.80000E-02, 0.10000E-01
537 , 0.15000E-01, 0.20000E-01, 0.30000E-01
538 , 0.40000E-01, 0.50000E-01, 0.60000E-01
539 , 0.80000E-01, 0.10000E+00, 0.15000E+00
540 , 0.20000E+00, 0.30000E+00, 0.40000E+00
541 , 0.50000E+00, 0.60000E+00, 0.80000E+00
542 , 0.10000E+01, 0.12500E+01, 0.15000E+01
543 , 0.20000E+01, 0.30000E+01, 0.40000E+01
544 , 0.50000E+01, 0.60000E+01, 0.80000E+01
545 , 0.10000E+02, 0.15000E+02, 0.20000E+02 };
547 return Interpolate(energyMeV,en,mu,kN);
551 //_____________________________________________________________________________
552 Double_t AliTRDsim::GetMuMy(Double_t energyMeV)
555 // Returns the photon absorbtion cross section for mylar
560 Double_t mu[kN] = { 2.911E+03, 9.536E+02, 4.206E+02
561 , 1.288E+02, 5.466E+01, 2.792E+01
562 , 1.608E+01, 6.750E+00, 3.481E+00
563 , 1.132E+00, 5.798E-01, 3.009E-01
564 , 2.304E-01, 2.020E-01, 1.868E-01
565 , 1.695E-01, 1.586E-01, 1.406E-01
566 , 1.282E-01, 1.111E-01, 9.947E-02
567 , 9.079E-02, 8.395E-02, 7.372E-02
568 , 6.628E-02, 5.927E-02, 5.395E-02
569 , 4.630E-02, 3.715E-02, 3.181E-02
570 , 2.829E-02, 2.582E-02, 2.257E-02
571 , 2.057E-02, 1.789E-02, 1.664E-02 };
573 Double_t en[kN] = { 1.00000E-03, 1.50000E-03, 2.00000E-03
574 , 3.00000E-03, 4.00000E-03, 5.00000E-03
575 , 6.00000E-03, 8.00000E-03, 1.00000E-02
576 , 1.50000E-02, 2.00000E-02, 3.00000E-02
577 , 4.00000E-02, 5.00000E-02, 6.00000E-02
578 , 8.00000E-02, 1.00000E-01, 1.50000E-01
579 , 2.00000E-01, 3.00000E-01, 4.00000E-01
580 , 5.00000E-01, 6.00000E-01, 8.00000E-01
581 , 1.00000E+00, 1.25000E+00, 1.50000E+00
582 , 2.00000E+00, 3.00000E+00, 4.00000E+00
583 , 5.00000E+00, 6.00000E+00, 8.00000E+00
584 , 1.00000E+01, 1.50000E+01, 2.00000E+01 };
586 return Interpolate(energyMeV,en,mu,kN);
590 //_____________________________________________________________________________
591 Double_t AliTRDsim::GetMuN2(Double_t energyMeV)
594 // Returns the photon absorbtion cross section for nitrogen
599 Double_t mu[kN] = { 3.311E+03, 1.083E+03, 4.769E+02
600 , 1.456E+02, 6.166E+01, 3.144E+01
601 , 1.809E+01, 7.562E+00, 3.879E+00
602 , 1.236E+00, 6.178E-01, 3.066E-01
603 , 2.288E-01, 1.980E-01, 1.817E-01
604 , 1.639E-01, 1.529E-01, 1.353E-01
605 , 1.233E-01, 1.068E-01, 9.557E-02
606 , 8.719E-02, 8.063E-02, 7.081E-02
607 , 6.364E-02, 5.693E-02, 5.180E-02
608 , 4.450E-02, 3.579E-02, 3.073E-02
609 , 2.742E-02, 2.511E-02, 2.209E-02
610 , 2.024E-02, 1.782E-02, 1.673E-02 };
612 Double_t en[kN] = { 1.00000E-03, 1.50000E-03, 2.00000E-03
613 , 3.00000E-03, 4.00000E-03, 5.00000E-03
614 , 6.00000E-03, 8.00000E-03, 1.00000E-02
615 , 1.50000E-02, 2.00000E-02, 3.00000E-02
616 , 4.00000E-02, 5.00000E-02, 6.00000E-02
617 , 8.00000E-02, 1.00000E-01, 1.50000E-01
618 , 2.00000E-01, 3.00000E-01, 4.00000E-01
619 , 5.00000E-01, 6.00000E-01, 8.00000E-01
620 , 1.00000E+00, 1.25000E+00, 1.50000E+00
621 , 2.00000E+00, 3.00000E+00, 4.00000E+00
622 , 5.00000E+00, 6.00000E+00, 8.00000E+00
623 , 1.00000E+01, 1.50000E+01, 2.00000E+01 };
625 return Interpolate(energyMeV,en,mu,kN);
629 //_____________________________________________________________________________
630 Double_t AliTRDsim::GetMuO2(Double_t energyMeV)
633 // Returns the photon absorbtion cross section for oxygen
638 Double_t mu[kN] = { 4.590E+03, 1.549E+03, 6.949E+02
639 , 2.171E+02, 9.315E+01, 4.790E+01
640 , 2.770E+01, 1.163E+01, 5.952E+00
641 , 1.836E+00, 8.651E-01, 3.779E-01
642 , 2.585E-01, 2.132E-01, 1.907E-01
643 , 1.678E-01, 1.551E-01, 1.361E-01
644 , 1.237E-01, 1.070E-01, 9.566E-02
645 , 8.729E-02, 8.070E-02, 7.087E-02
646 , 6.372E-02, 5.697E-02, 5.185E-02
647 , 4.459E-02, 3.597E-02, 3.100E-02
648 , 2.777E-02, 2.552E-02, 2.263E-02
649 , 2.089E-02, 1.866E-02, 1.770E-02 };
651 Double_t en[kN] = { 1.00000E-03, 1.50000E-03, 2.00000E-03
652 , 3.00000E-03, 4.00000E-03, 5.00000E-03
653 , 6.00000E-03, 8.00000E-03, 1.00000E-02
654 , 1.50000E-02, 2.00000E-02, 3.00000E-02
655 , 4.00000E-02, 5.00000E-02, 6.00000E-02
656 , 8.00000E-02, 1.00000E-01, 1.50000E-01
657 , 2.00000E-01, 3.00000E-01, 4.00000E-01
658 , 5.00000E-01, 6.00000E-01, 8.00000E-01
659 , 1.00000E+00, 1.25000E+00, 1.50000E+00
660 , 2.00000E+00, 3.00000E+00, 4.00000E+00
661 , 5.00000E+00, 6.00000E+00, 8.00000E+00
662 , 1.00000E+01, 1.50000E+01, 2.00000E+01 };
664 return Interpolate(energyMeV,en,mu,kN);
668 //_____________________________________________________________________________
669 Double_t AliTRDsim::GetMuHe(Double_t energyMeV)
672 // Returns the photon absorbtion cross section for helium
677 Double_t mu[kN] = { 6.084E+01, 1.676E+01, 6.863E+00
678 , 2.007E+00, 9.329E-01, 5.766E-01
679 , 4.195E-01, 2.933E-01, 2.476E-01
680 , 2.092E-01, 1.960E-01, 1.838E-01
681 , 1.763E-01, 1.703E-01, 1.651E-01
682 , 1.562E-01, 1.486E-01, 1.336E-01
683 , 1.224E-01, 1.064E-01, 9.535E-02
684 , 8.707E-02, 8.054E-02, 7.076E-02
685 , 6.362E-02, 5.688E-02, 5.173E-02
686 , 4.422E-02, 3.503E-02, 2.949E-02
687 , 2.577E-02, 2.307E-02, 1.940E-02
688 , 1.703E-02, 1.363E-02, 1.183E-02 };
690 Double_t en[kN] = { 1.00000E-03, 1.50000E-03, 2.00000E-03
691 , 3.00000E-03, 4.00000E-03, 5.00000E-03
692 , 6.00000E-03, 8.00000E-03, 1.00000E-02
693 , 1.50000E-02, 2.00000E-02, 3.00000E-02
694 , 4.00000E-02, 5.00000E-02, 6.00000E-02
695 , 8.00000E-02, 1.00000E-01, 1.50000E-01
696 , 2.00000E-01, 3.00000E-01, 4.00000E-01
697 , 5.00000E-01, 6.00000E-01, 8.00000E-01
698 , 1.00000E+00, 1.25000E+00, 1.50000E+00
699 , 2.00000E+00, 3.00000E+00, 4.00000E+00
700 , 5.00000E+00, 6.00000E+00, 8.00000E+00
701 , 1.00000E+01, 1.50000E+01, 2.00000E+01 };
703 return Interpolate(energyMeV,en,mu,kN);
707 //_____________________________________________________________________________
708 Double_t AliTRDsim::GetMuAi(Double_t energyMeV)
711 // Returns the photon absorbtion cross section for air
712 // Implemented by Oliver Busch
717 Double_t mu[kN] = { 0.35854E+04, 0.11841E+04, 0.52458E+03,
718 0.16143E+03, 0.14250E+03, 0.15722E+03,
719 0.77538E+02, 0.40099E+02, 0.23313E+02,
720 0.98816E+01, 0.51000E+01, 0.16079E+01,
721 0.77536E+00, 0.35282E+00, 0.24790E+00,
722 0.20750E+00, 0.18703E+00, 0.16589E+00,
723 0.15375E+00, 0.13530E+00, 0.12311E+00,
724 0.10654E+00, 0.95297E-01, 0.86939E-01,
725 0.80390E-01, 0.70596E-01, 0.63452E-01,
726 0.56754E-01, 0.51644E-01, 0.44382E-01,
727 0.35733E-01, 0.30721E-01, 0.27450E-01,
728 0.25171E-01, 0.22205E-01, 0.20399E-01,
729 0.18053E-01, 0.18057E-01 };
733 Double_t en[kN] = { 0.10000E-02, 0.15000E-02, 0.20000E-02,
734 0.30000E-02, 0.32029E-02, 0.32029E-02,
735 0.40000E-02, 0.50000E-02, 0.60000E-02,
736 0.80000E-02, 0.10000E-01, 0.15000E-01,
737 0.20000E-01, 0.30000E-01, 0.40000E-01,
738 0.50000E-01, 0.60000E-01, 0.80000E-01,
739 0.10000E+00, 0.15000E+00, 0.20000E+00,
740 0.30000E+00, 0.40000E+00, 0.50000E+00,
741 0.60000E+00, 0.80000E+00, 0.10000E+01,
742 0.12500E+01, 0.15000E+01, 0.20000E+01,
743 0.30000E+01, 0.40000E+01, 0.50000E+01,
744 0.60000E+01, 0.80000E+01, 0.10000E+02,
745 0.15000E+02, 0.20000E+02 };
747 return Interpolate(energyMeV,en,mu,kN);
751 //_____________________________________________________________________________
752 Double_t AliTRDsim::Interpolate(Double_t energyMeV
753 , Double_t *en, Double_t *mu, Int_t n)
756 // Interpolates the photon absorbtion cross section
757 // for a given energy <energyMeV>.
762 Int_t istat = Locate(en,n,energyMeV,index,de);
764 return (mu[index] - de * (mu[index] - mu[index+1])
765 / (en[index+1] - en[index] ));
773 //_____________________________________________________________________________
774 Int_t AliTRDsim::Locate(Double_t *xv, Int_t n, Double_t xval
775 , Int_t &kl, Double_t &dx)
778 // Locates a point (xval) in a 1-dim grid (xv(n))
781 if (xval >= xv[n-1]) return 1;
782 if (xval < xv[0]) return -1;
788 while (kh - kl > 1) {
789 if (xval < xv[km = (kl+kh)/2]) kh = km;
792 if (xval < xv[kl] || xval > xv[kl+1] || kl >= n-1) {
793 printf("Locate failed xv[%d] %f xval %f xv[%d] %f!!!\n"
794 ,kl,xv[kl],xval,kl+1,xv[kl+1]);
804 //_____________________________________________________________________________
805 Int_t AliTRDsim::SelectNFoils(Float_t p)
808 // Selects the number of foils corresponding to the momentum
811 Int_t foils = fNFoils[fNFoilsDim-1];
813 for (Int_t iFoil = 0; iFoil < fNFoilsDim; iFoil++) {
814 if (p < fNFoilsUp[iFoil]) {
815 foils = fNFoils[iFoil];