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"
42 #include "AliTRDsim.h"
46 //_____________________________________________________________________________
47 AliTRDsim::AliTRDsim()
72 // AliTRDsim default constructor
79 //_____________________________________________________________________________
80 AliTRDsim::AliTRDsim(AliModule *mod, Int_t foil, Int_t gap)
105 // AliTRDsim constructor. Takes the material properties of the radiator
106 // foils and the gas in the gaps from AliModule <mod>.
107 // The default number of foils is 100 with a thickness of 20 mu. The
108 // thickness of the gaps is 500 mu.
126 mod->AliGetMaterial(foil,name,aFoil,zFoil,rhoFoil,rad,abs);
127 mod->AliGetMaterial(gap ,name,aGap ,zGap ,rhoGap ,rad,abs);
132 fFoilOmega = Omega(fFoilDens,fFoilZ,fFoilA);
137 fGapOmega = Omega(fGapDens ,fGapZ ,fGapA );
141 //_____________________________________________________________________________
142 AliTRDsim::AliTRDsim(const AliTRDsim &s)
144 ,fNFoilsDim(s.fNFoilsDim)
147 ,fFoilThick(s.fFoilThick)
148 ,fGapThick(s.fGapThick)
149 ,fFoilDens(s.fFoilDens)
150 ,fGapDens(s.fGapDens)
151 ,fFoilOmega(s.fFoilOmega)
152 ,fGapOmega(s.fGapOmega)
158 ,fSpNBins(s.fSpNBins)
159 ,fSpRange(s.fSpRange)
160 ,fSpBinWidth(s.fSpBinWidth)
161 ,fSpLower(s.fSpLower)
162 ,fSpUpper(s.fSpUpper)
167 // AliTRDsim copy constructor
170 if (((AliTRDsim &) s).fNFoils) {
171 delete [] ((AliTRDsim &) s).fNFoils;
173 ((AliTRDsim &) s).fNFoils = new Int_t[fNFoilsDim];
174 for (Int_t iFoil = 0; iFoil < fNFoilsDim; iFoil++) {
175 ((AliTRDsim &) s).fNFoils[iFoil] = fNFoils[iFoil];
178 if (((AliTRDsim &) s).fNFoilsUp) {
179 delete [] ((AliTRDsim &) s).fNFoilsUp;
181 ((AliTRDsim &) s).fNFoilsUp = new Double_t[fNFoilsDim];
182 for (Int_t iFoil = 0; iFoil < fNFoilsDim; iFoil++) {
183 ((AliTRDsim &) s).fNFoilsUp[iFoil] = fNFoilsUp[iFoil];
186 if (((AliTRDsim &) s).fSigma) {
187 delete [] ((AliTRDsim &) s).fSigma;
189 ((AliTRDsim &) s).fSigma = new Double_t[fSpNBins];
190 for (Int_t iBin = 0; iBin < fSpNBins; iBin++) {
191 ((AliTRDsim &) s).fSigma[iBin] = fSigma[iBin];
194 fSpectrum->Copy(*((AliTRDsim &) s).fSpectrum);
198 //_____________________________________________________________________________
199 AliTRDsim::~AliTRDsim()
202 // AliTRDsim destructor
222 //_____________________________________________________________________________
223 AliTRDsim &AliTRDsim::operator=(const AliTRDsim &s)
226 // Assignment operator
229 if (this != &s) ((AliTRDsim &) s).Copy(*this);
235 //_____________________________________________________________________________
236 void AliTRDsim::Copy(TObject &s) const
242 ((AliTRDsim &) s).fFoilThick = fFoilThick;
243 ((AliTRDsim &) s).fFoilDens = fFoilDens;
244 ((AliTRDsim &) s).fFoilOmega = fFoilOmega;
245 ((AliTRDsim &) s).fFoilZ = fFoilZ;
246 ((AliTRDsim &) s).fFoilA = fFoilA;
247 ((AliTRDsim &) s).fGapThick = fGapThick;
248 ((AliTRDsim &) s).fGapDens = fGapDens;
249 ((AliTRDsim &) s).fGapOmega = fGapOmega;
250 ((AliTRDsim &) s).fGapZ = fGapZ;
251 ((AliTRDsim &) s).fGapA = fGapA;
252 ((AliTRDsim &) s).fTemp = fTemp;
253 ((AliTRDsim &) s).fSpNBins = fSpNBins;
254 ((AliTRDsim &) s).fSpRange = fSpRange;
255 ((AliTRDsim &) s).fSpBinWidth = fSpBinWidth;
256 ((AliTRDsim &) s).fSpLower = fSpLower;
257 ((AliTRDsim &) s).fSpUpper = fSpUpper;
259 if (((AliTRDsim &) s).fNFoils) {
260 delete [] ((AliTRDsim &) s).fNFoils;
262 ((AliTRDsim &) s).fNFoils = new Int_t[fNFoilsDim];
263 for (Int_t iFoil = 0; iFoil < fNFoilsDim; iFoil++) {
264 ((AliTRDsim &) s).fNFoils[iFoil] = fNFoils[iFoil];
267 if (((AliTRDsim &) s).fNFoilsUp) {
268 delete [] ((AliTRDsim &) s).fNFoilsUp;
270 ((AliTRDsim &) s).fNFoilsUp = new Double_t[fNFoilsDim];
271 for (Int_t iFoil = 0; iFoil < fNFoilsDim; iFoil++) {
272 ((AliTRDsim &) s).fNFoilsUp[iFoil] = fNFoilsUp[iFoil];
275 if (((AliTRDsim &) s).fSigma) {
276 delete [] ((AliTRDsim &) s).fSigma;
278 ((AliTRDsim &) s).fSigma = new Double_t[fSpNBins];
279 for (Int_t iBin = 0; iBin < fSpNBins; iBin++) {
280 ((AliTRDsim &) s).fSigma[iBin] = fSigma[iBin];
283 fSpectrum->Copy(*((AliTRDsim &) s).fSpectrum);
287 //_____________________________________________________________________________
288 void AliTRDsim::Init()
292 // The default radiator are prolypropilene foils of 10 mu thickness
293 // with gaps of 80 mu filled with N2.
301 fNFoils = new Int_t[fNFoilsDim];
313 fNFoilsUp = new Double_t[fNFoilsDim];
320 fNFoilsUp[6] = 10000.0;
326 fFoilOmega = Omega(fFoilDens,fFoilZ,fFoilA);
332 fGapOmega = Omega(fGapDens ,fGapZ ,fGapA );
338 fSpBinWidth = fSpRange / fSpNBins;
339 fSpLower = 1.0 - 0.5 * fSpBinWidth;
340 fSpUpper = fSpLower + fSpRange;
342 if (fSpectrum) delete fSpectrum;
343 fSpectrum = new TH1D("TRspectrum","TR spectrum",fSpNBins,fSpLower,fSpUpper);
344 fSpectrum->SetDirectory(0);
346 // Set the sigma values
351 //_____________________________________________________________________________
352 Int_t AliTRDsim::CreatePhotons(Int_t pdg, Float_t p
353 , Int_t &nPhoton, Float_t *ePhoton)
356 // Create TRD photons for a charged particle of type <pdg> with the total
358 // Number of produced TR photons: <nPhoton>
359 // Energies of the produced TR photons: <ePhoton>
363 const Int_t kPdgEle = 11;
364 const Int_t kPdgMuon = 13;
365 const Int_t kPdgPion = 211;
366 const Int_t kPdgKaon = 321;
369 switch (TMath::Abs(pdg)) {
387 // Calculate the TR photons
388 return TrPhotons(p, mass, nPhoton, ePhoton);
392 //_____________________________________________________________________________
393 Int_t AliTRDsim::TrPhotons(Float_t p, Float_t mass
394 , Int_t &nPhoton, Float_t *ePhoton)
397 // Produces TR photons.
400 const Double_t kAlpha = 0.0072973;
401 const Int_t kSumMax = 30;
403 Double_t tau = fGapThick / fFoilThick;
406 Double_t gamma = TMath::Sqrt(p*p + mass*mass) / mass;
408 // Select the number of foils corresponding to momentum
409 Int_t foils = SelectNFoils(p);
429 for (Int_t iBin = 1; iBin <= fSpNBins; iBin++) {
431 energykeV = fSpectrum->GetBinCenter(iBin);
432 energyeV = energykeV * 1.e3;
433 sSigma = Sigma(energykeV);
435 csi1 = fFoilOmega / energyeV;
436 csi2 = fGapOmega / energyeV;
438 rho1 = 2.5 * energyeV * fFoilThick * 1.0e4
439 * (1. / (gamma*gamma) + csi1*csi1);
440 rho2 = 2.5 * energyeV * fFoilThick * 1.0e4
441 * (1.0 / (gamma*gamma) + csi2 *csi2);
445 for (Int_t n = 1; n <= kSumMax; n++) {
446 thetaN = (TMath::Pi() * 2.0 * n - (rho1 + tau * rho2)) / (1.0 + tau);
450 aux = 1.0 / (rho1 + thetaN) - 1.0 / (rho2 + thetaN);
451 sum += thetaN * (aux*aux) * (1.0 - TMath::Cos(rho1 + thetaN));
454 // Equivalent number of foils
455 nEqu = (1.0 - TMath::Exp(-foils * sSigma)) / (1.0 - TMath::Exp(-sSigma));
458 fSpectrum->SetBinContent(iBin,4.0 * kAlpha * nEqu * sum / (energykeV * (1.0 + tau)));
462 // <nTR> (binsize corr.)
463 Float_t ntr = fSpBinWidth*fSpectrum->Integral();
464 // Number of TR photons from Poisson distribution with mean <ntr>
465 nPhoton = gRandom->Poisson(ntr);
466 // Energy of the TR photons
467 for (Int_t iPhoton = 0; iPhoton < nPhoton; iPhoton++) {
468 ePhoton[iPhoton] = fSpectrum->GetRandom();
475 //_____________________________________________________________________________
476 void AliTRDsim::SetSigma()
479 // Sets the absorbtion crosssection for the energies of the TR spectrum
485 fSigma = new Double_t[fSpNBins];
487 for (Int_t iBin = 0; iBin < fSpNBins; iBin++) {
488 Double_t energykeV = iBin * fSpBinWidth + 1.0;
489 fSigma[iBin] = Sigma(energykeV);
494 //_____________________________________________________________________________
495 Double_t AliTRDsim::Sigma(Double_t energykeV)
498 // Calculates the absorbtion crosssection for a one-foil-one-gap-radiator
502 Double_t energyMeV = energykeV * 0.001;
503 if (energyMeV >= 0.001) {
504 return(GetMuPo(energyMeV) * fFoilDens * fFoilThick +
505 GetMuAi(energyMeV) * fGapDens * fGapThick * GetTemp());
513 //_____________________________________________________________________________
514 Double_t AliTRDsim::GetMuPo(Double_t energyMeV)
517 // Returns the photon absorbtion cross section for polypropylene
522 Double_t mu[kN] = { 1.894E+03, 5.999E+02, 2.593E+02
523 , 7.743E+01, 3.242E+01, 1.643E+01
524 , 9.432E+00, 3.975E+00, 2.088E+00
525 , 7.452E-01, 4.315E-01, 2.706E-01
526 , 2.275E-01, 2.084E-01, 1.970E-01
527 , 1.823E-01, 1.719E-01, 1.534E-01
528 , 1.402E-01, 1.217E-01, 1.089E-01
529 , 9.947E-02, 9.198E-02, 8.078E-02
530 , 7.262E-02, 6.495E-02, 5.910E-02
531 , 5.064E-02, 4.045E-02, 3.444E-02
532 , 3.045E-02, 2.760E-02, 2.383E-02
533 , 2.145E-02, 1.819E-02, 1.658E-02 };
535 Double_t en[kN] = { 1.000E-03, 1.500E-03, 2.000E-03
536 , 3.000E-03, 4.000E-03, 5.000E-03
537 , 6.000E-03, 8.000E-03, 1.000E-02
538 , 1.500E-02, 2.000E-02, 3.000E-02
539 , 4.000E-02, 5.000E-02, 6.000E-02
540 , 8.000E-02, 1.000E-01, 1.500E-01
541 , 2.000E-01, 3.000E-01, 4.000E-01
542 , 5.000E-01, 6.000E-01, 8.000E-01
543 , 1.000E+00, 1.250E+00, 1.500E+00
544 , 2.000E+00, 3.000E+00, 4.000E+00
545 , 5.000E+00, 6.000E+00, 8.000E+00
546 , 1.000E+01, 1.500E+01, 2.000E+01 };
548 return Interpolate(energyMeV,en,mu,kN);
552 //_____________________________________________________________________________
553 Double_t AliTRDsim::GetMuCO(Double_t energyMeV)
556 // Returns the photon absorbtion cross section for CO2
561 Double_t mu[kN] = { 0.39383E+04, 0.13166E+04, 0.58750E+03
562 , 0.18240E+03, 0.77996E+02, 0.40024E+02
563 , 0.23116E+02, 0.96997E+01, 0.49726E+01
564 , 0.15543E+01, 0.74915E+00, 0.34442E+00
565 , 0.24440E+00, 0.20589E+00, 0.18632E+00
566 , 0.16578E+00, 0.15394E+00, 0.13558E+00
567 , 0.12336E+00, 0.10678E+00, 0.95510E-01
568 , 0.87165E-01, 0.80587E-01, 0.70769E-01
569 , 0.63626E-01, 0.56894E-01, 0.51782E-01
570 , 0.44499E-01, 0.35839E-01, 0.30825E-01
571 , 0.27555E-01, 0.25269E-01, 0.22311E-01
572 , 0.20516E-01, 0.18184E-01, 0.17152E-01 };
574 Double_t en[kN] = { 0.10000E-02, 0.15000E-02, 0.20000E-02
575 , 0.30000E-02, 0.40000E-02, 0.50000E-02
576 , 0.60000E-02, 0.80000E-02, 0.10000E-01
577 , 0.15000E-01, 0.20000E-01, 0.30000E-01
578 , 0.40000E-01, 0.50000E-01, 0.60000E-01
579 , 0.80000E-01, 0.10000E+00, 0.15000E+00
580 , 0.20000E+00, 0.30000E+00, 0.40000E+00
581 , 0.50000E+00, 0.60000E+00, 0.80000E+00
582 , 0.10000E+01, 0.12500E+01, 0.15000E+01
583 , 0.20000E+01, 0.30000E+01, 0.40000E+01
584 , 0.50000E+01, 0.60000E+01, 0.80000E+01
585 , 0.10000E+02, 0.15000E+02, 0.20000E+02 };
587 return Interpolate(energyMeV,en,mu,kN);
591 //_____________________________________________________________________________
592 Double_t AliTRDsim::GetMuXe(Double_t energyMeV)
595 // Returns the photon absorbtion cross section for xenon
600 Double_t mu[kN] = { 9.413E+03, 8.151E+03, 7.035E+03
601 , 7.338E+03, 4.085E+03, 2.088E+03
602 , 7.780E+02, 3.787E+02, 2.408E+02
603 , 6.941E+02, 6.392E+02, 6.044E+02
604 , 8.181E+02, 7.579E+02, 6.991E+02
605 , 8.064E+02, 6.376E+02, 3.032E+02
606 , 1.690E+02, 5.743E+01, 2.652E+01
607 , 8.930E+00, 6.129E+00, 3.316E+01
608 , 2.270E+01, 1.272E+01, 7.825E+00
609 , 3.633E+00, 2.011E+00, 7.202E-01
610 , 3.760E-01, 1.797E-01, 1.223E-01
611 , 9.699E-02, 8.281E-02, 6.696E-02
612 , 5.785E-02, 5.054E-02, 4.594E-02
613 , 4.078E-02, 3.681E-02, 3.577E-02
614 , 3.583E-02, 3.634E-02, 3.797E-02
615 , 3.987E-02, 4.445E-02, 4.815E-02 };
617 Double_t en[kN] = { 1.00000E-03, 1.07191E-03, 1.14900E-03
618 , 1.14900E-03, 1.50000E-03, 2.00000E-03
619 , 3.00000E-03, 4.00000E-03, 4.78220E-03
620 , 4.78220E-03, 5.00000E-03, 5.10370E-03
621 , 5.10370E-03, 5.27536E-03, 5.45280E-03
622 , 5.45280E-03, 6.00000E-03, 8.00000E-03
623 , 1.00000E-02, 1.50000E-02, 2.00000E-02
624 , 3.00000E-02, 3.45614E-02, 3.45614E-02
625 , 4.00000E-02, 5.00000E-02, 6.00000E-02
626 , 8.00000E-02, 1.00000E-01, 1.50000E-01
627 , 2.00000E-01, 3.00000E-01, 4.00000E-01
628 , 5.00000E-01, 6.00000E-01, 8.00000E-01
629 , 1.00000E+00, 1.25000E+00, 1.50000E+00
630 , 2.00000E+00, 3.00000E+00, 4.00000E+00
631 , 5.00000E+00, 6.00000E+00, 8.00000E+00
632 , 1.00000E+01, 1.50000E+01, 2.00000E+01 };
634 return Interpolate(energyMeV,en,mu,kN);
638 //_____________________________________________________________________________
639 Double_t AliTRDsim::GetMuBu(Double_t energyMeV)
642 // Returns the photon absorbtion cross section for isobutane
647 Double_t mu[kN] = { 0.38846E+03, 0.12291E+03, 0.53225E+02
648 , 0.16091E+02, 0.69114E+01, 0.36541E+01
649 , 0.22282E+01, 0.11149E+01, 0.72887E+00
650 , 0.45053E+00, 0.38167E+00, 0.33920E+00
651 , 0.32155E+00, 0.30949E+00, 0.29960E+00
652 , 0.28317E+00, 0.26937E+00, 0.24228E+00
653 , 0.22190E+00, 0.19289E+00, 0.17288E+00
654 , 0.15789E+00, 0.14602E+00, 0.12829E+00
655 , 0.11533E+00, 0.10310E+00, 0.93790E-01
656 , 0.80117E-01, 0.63330E-01, 0.53229E-01
657 , 0.46390E-01, 0.41425E-01, 0.34668E-01
658 , 0.30267E-01, 0.23910E-01, 0.20509E-01 };
660 Double_t en[kN] = { 0.10000E-02, 0.15000E-02, 0.20000E-02
661 , 0.30000E-02, 0.40000E-02, 0.50000E-02
662 , 0.60000E-02, 0.80000E-02, 0.10000E-01
663 , 0.15000E-01, 0.20000E-01, 0.30000E-01
664 , 0.40000E-01, 0.50000E-01, 0.60000E-01
665 , 0.80000E-01, 0.10000E+00, 0.15000E+00
666 , 0.20000E+00, 0.30000E+00, 0.40000E+00
667 , 0.50000E+00, 0.60000E+00, 0.80000E+00
668 , 0.10000E+01, 0.12500E+01, 0.15000E+01
669 , 0.20000E+01, 0.30000E+01, 0.40000E+01
670 , 0.50000E+01, 0.60000E+01, 0.80000E+01
671 , 0.10000E+02, 0.15000E+02, 0.20000E+02 };
673 return Interpolate(energyMeV,en,mu,kN);
677 //_____________________________________________________________________________
678 Double_t AliTRDsim::GetMuMy(Double_t energyMeV)
681 // Returns the photon absorbtion cross section for mylar
686 Double_t mu[kN] = { 2.911E+03, 9.536E+02, 4.206E+02
687 , 1.288E+02, 5.466E+01, 2.792E+01
688 , 1.608E+01, 6.750E+00, 3.481E+00
689 , 1.132E+00, 5.798E-01, 3.009E-01
690 , 2.304E-01, 2.020E-01, 1.868E-01
691 , 1.695E-01, 1.586E-01, 1.406E-01
692 , 1.282E-01, 1.111E-01, 9.947E-02
693 , 9.079E-02, 8.395E-02, 7.372E-02
694 , 6.628E-02, 5.927E-02, 5.395E-02
695 , 4.630E-02, 3.715E-02, 3.181E-02
696 , 2.829E-02, 2.582E-02, 2.257E-02
697 , 2.057E-02, 1.789E-02, 1.664E-02 };
699 Double_t en[kN] = { 1.00000E-03, 1.50000E-03, 2.00000E-03
700 , 3.00000E-03, 4.00000E-03, 5.00000E-03
701 , 6.00000E-03, 8.00000E-03, 1.00000E-02
702 , 1.50000E-02, 2.00000E-02, 3.00000E-02
703 , 4.00000E-02, 5.00000E-02, 6.00000E-02
704 , 8.00000E-02, 1.00000E-01, 1.50000E-01
705 , 2.00000E-01, 3.00000E-01, 4.00000E-01
706 , 5.00000E-01, 6.00000E-01, 8.00000E-01
707 , 1.00000E+00, 1.25000E+00, 1.50000E+00
708 , 2.00000E+00, 3.00000E+00, 4.00000E+00
709 , 5.00000E+00, 6.00000E+00, 8.00000E+00
710 , 1.00000E+01, 1.50000E+01, 2.00000E+01 };
712 return Interpolate(energyMeV,en,mu,kN);
716 //_____________________________________________________________________________
717 Double_t AliTRDsim::GetMuN2(Double_t energyMeV)
720 // Returns the photon absorbtion cross section for nitrogen
725 Double_t mu[kN] = { 3.311E+03, 1.083E+03, 4.769E+02
726 , 1.456E+02, 6.166E+01, 3.144E+01
727 , 1.809E+01, 7.562E+00, 3.879E+00
728 , 1.236E+00, 6.178E-01, 3.066E-01
729 , 2.288E-01, 1.980E-01, 1.817E-01
730 , 1.639E-01, 1.529E-01, 1.353E-01
731 , 1.233E-01, 1.068E-01, 9.557E-02
732 , 8.719E-02, 8.063E-02, 7.081E-02
733 , 6.364E-02, 5.693E-02, 5.180E-02
734 , 4.450E-02, 3.579E-02, 3.073E-02
735 , 2.742E-02, 2.511E-02, 2.209E-02
736 , 2.024E-02, 1.782E-02, 1.673E-02 };
738 Double_t en[kN] = { 1.00000E-03, 1.50000E-03, 2.00000E-03
739 , 3.00000E-03, 4.00000E-03, 5.00000E-03
740 , 6.00000E-03, 8.00000E-03, 1.00000E-02
741 , 1.50000E-02, 2.00000E-02, 3.00000E-02
742 , 4.00000E-02, 5.00000E-02, 6.00000E-02
743 , 8.00000E-02, 1.00000E-01, 1.50000E-01
744 , 2.00000E-01, 3.00000E-01, 4.00000E-01
745 , 5.00000E-01, 6.00000E-01, 8.00000E-01
746 , 1.00000E+00, 1.25000E+00, 1.50000E+00
747 , 2.00000E+00, 3.00000E+00, 4.00000E+00
748 , 5.00000E+00, 6.00000E+00, 8.00000E+00
749 , 1.00000E+01, 1.50000E+01, 2.00000E+01 };
751 return Interpolate(energyMeV,en,mu,kN);
755 //_____________________________________________________________________________
756 Double_t AliTRDsim::GetMuO2(Double_t energyMeV)
759 // Returns the photon absorbtion cross section for oxygen
764 Double_t mu[kN] = { 4.590E+03, 1.549E+03, 6.949E+02
765 , 2.171E+02, 9.315E+01, 4.790E+01
766 , 2.770E+01, 1.163E+01, 5.952E+00
767 , 1.836E+00, 8.651E-01, 3.779E-01
768 , 2.585E-01, 2.132E-01, 1.907E-01
769 , 1.678E-01, 1.551E-01, 1.361E-01
770 , 1.237E-01, 1.070E-01, 9.566E-02
771 , 8.729E-02, 8.070E-02, 7.087E-02
772 , 6.372E-02, 5.697E-02, 5.185E-02
773 , 4.459E-02, 3.597E-02, 3.100E-02
774 , 2.777E-02, 2.552E-02, 2.263E-02
775 , 2.089E-02, 1.866E-02, 1.770E-02 };
777 Double_t en[kN] = { 1.00000E-03, 1.50000E-03, 2.00000E-03
778 , 3.00000E-03, 4.00000E-03, 5.00000E-03
779 , 6.00000E-03, 8.00000E-03, 1.00000E-02
780 , 1.50000E-02, 2.00000E-02, 3.00000E-02
781 , 4.00000E-02, 5.00000E-02, 6.00000E-02
782 , 8.00000E-02, 1.00000E-01, 1.50000E-01
783 , 2.00000E-01, 3.00000E-01, 4.00000E-01
784 , 5.00000E-01, 6.00000E-01, 8.00000E-01
785 , 1.00000E+00, 1.25000E+00, 1.50000E+00
786 , 2.00000E+00, 3.00000E+00, 4.00000E+00
787 , 5.00000E+00, 6.00000E+00, 8.00000E+00
788 , 1.00000E+01, 1.50000E+01, 2.00000E+01 };
790 return Interpolate(energyMeV,en,mu,kN);
794 //_____________________________________________________________________________
795 Double_t AliTRDsim::GetMuHe(Double_t energyMeV)
798 // Returns the photon absorbtion cross section for helium
803 Double_t mu[kN] = { 6.084E+01, 1.676E+01, 6.863E+00
804 , 2.007E+00, 9.329E-01, 5.766E-01
805 , 4.195E-01, 2.933E-01, 2.476E-01
806 , 2.092E-01, 1.960E-01, 1.838E-01
807 , 1.763E-01, 1.703E-01, 1.651E-01
808 , 1.562E-01, 1.486E-01, 1.336E-01
809 , 1.224E-01, 1.064E-01, 9.535E-02
810 , 8.707E-02, 8.054E-02, 7.076E-02
811 , 6.362E-02, 5.688E-02, 5.173E-02
812 , 4.422E-02, 3.503E-02, 2.949E-02
813 , 2.577E-02, 2.307E-02, 1.940E-02
814 , 1.703E-02, 1.363E-02, 1.183E-02 };
816 Double_t en[kN] = { 1.00000E-03, 1.50000E-03, 2.00000E-03
817 , 3.00000E-03, 4.00000E-03, 5.00000E-03
818 , 6.00000E-03, 8.00000E-03, 1.00000E-02
819 , 1.50000E-02, 2.00000E-02, 3.00000E-02
820 , 4.00000E-02, 5.00000E-02, 6.00000E-02
821 , 8.00000E-02, 1.00000E-01, 1.50000E-01
822 , 2.00000E-01, 3.00000E-01, 4.00000E-01
823 , 5.00000E-01, 6.00000E-01, 8.00000E-01
824 , 1.00000E+00, 1.25000E+00, 1.50000E+00
825 , 2.00000E+00, 3.00000E+00, 4.00000E+00
826 , 5.00000E+00, 6.00000E+00, 8.00000E+00
827 , 1.00000E+01, 1.50000E+01, 2.00000E+01 };
829 return Interpolate(energyMeV,en,mu,kN);
833 //_____________________________________________________________________________
834 Double_t AliTRDsim::GetMuAi(Double_t energyMeV)
837 // Returns the photon absorbtion cross section for air
838 // Implemented by Oliver Busch
843 Double_t mu[kN] = { 0.35854E+04, 0.11841E+04, 0.52458E+03,
844 0.16143E+03, 0.14250E+03, 0.15722E+03,
845 0.77538E+02, 0.40099E+02, 0.23313E+02,
846 0.98816E+01, 0.51000E+01, 0.16079E+01,
847 0.77536E+00, 0.35282E+00, 0.24790E+00,
848 0.20750E+00, 0.18703E+00, 0.16589E+00,
849 0.15375E+00, 0.13530E+00, 0.12311E+00,
850 0.10654E+00, 0.95297E-01, 0.86939E-01,
851 0.80390E-01, 0.70596E-01, 0.63452E-01,
852 0.56754E-01, 0.51644E-01, 0.44382E-01,
853 0.35733E-01, 0.30721E-01, 0.27450E-01,
854 0.25171E-01, 0.22205E-01, 0.20399E-01,
855 0.18053E-01, 0.18057E-01 };
859 Double_t en[kN] = { 0.10000E-02, 0.15000E-02, 0.20000E-02,
860 0.30000E-02, 0.32029E-02, 0.32029E-02,
861 0.40000E-02, 0.50000E-02, 0.60000E-02,
862 0.80000E-02, 0.10000E-01, 0.15000E-01,
863 0.20000E-01, 0.30000E-01, 0.40000E-01,
864 0.50000E-01, 0.60000E-01, 0.80000E-01,
865 0.10000E+00, 0.15000E+00, 0.20000E+00,
866 0.30000E+00, 0.40000E+00, 0.50000E+00,
867 0.60000E+00, 0.80000E+00, 0.10000E+01,
868 0.12500E+01, 0.15000E+01, 0.20000E+01,
869 0.30000E+01, 0.40000E+01, 0.50000E+01,
870 0.60000E+01, 0.80000E+01, 0.10000E+02,
871 0.15000E+02, 0.20000E+02 };
873 return Interpolate(energyMeV,en,mu,kN);
877 //_____________________________________________________________________________
878 Double_t AliTRDsim::Interpolate(Double_t energyMeV
879 , Double_t *en, Double_t *mu, Int_t n)
882 // Interpolates the photon absorbtion cross section
883 // for a given energy <energyMeV>.
888 Int_t istat = Locate(en,n,energyMeV,index,de);
890 return (mu[index] - de * (mu[index] - mu[index+1])
891 / (en[index+1] - en[index] ));
899 //_____________________________________________________________________________
900 Int_t AliTRDsim::Locate(Double_t *xv, Int_t n, Double_t xval
901 , Int_t &kl, Double_t &dx)
904 // Locates a point (xval) in a 1-dim grid (xv(n))
907 if (xval >= xv[n-1]) {
918 while (kh - kl > 1) {
919 if (xval < xv[km = (kl+kh)/2]) {
926 if ((xval < xv[kl]) ||
929 AliError(Form("Locate failed xv[%d] %f xval %f xv[%d] %f!!!\n"
930 ,kl,xv[kl],xval,kl+1,xv[kl+1]));
940 //_____________________________________________________________________________
941 Int_t AliTRDsim::SelectNFoils(Float_t p)
944 // Selects the number of foils corresponding to the momentum
947 Int_t foils = fNFoils[fNFoilsDim-1];
949 for (Int_t iFoil = 0; iFoil < fNFoilsDim; iFoil++) {
950 if (p < fNFoilsUp[iFoil]) {
951 foils = fNFoils[iFoil];