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>
38 #include <TVirtualMC.h>
39 #include <TVirtualMCStack.h>
41 #include "AliModule.h"
45 #include "AliTRDsim.h"
49 //_____________________________________________________________________________
50 AliTRDsim::AliTRDsim()
75 // AliTRDsim default constructor
82 //_____________________________________________________________________________
83 AliTRDsim::AliTRDsim(AliModule *mod, Int_t foil, Int_t gap)
108 // AliTRDsim constructor. Takes the material properties of the radiator
109 // foils and the gas in the gaps from AliModule <mod>.
110 // The default number of foils is 100 with a thickness of 20 mu. The
111 // thickness of the gaps is 500 mu.
129 mod->AliGetMaterial(foil,name,aFoil,zFoil,rhoFoil,rad,abs);
130 mod->AliGetMaterial(gap ,name,aGap ,zGap ,rhoGap ,rad,abs);
135 fFoilOmega = Omega(fFoilDens,fFoilZ,fFoilA);
140 fGapOmega = Omega(fGapDens ,fGapZ ,fGapA );
144 //_____________________________________________________________________________
145 AliTRDsim::AliTRDsim(const AliTRDsim &s)
147 ,fNFoilsDim(s.fNFoilsDim)
150 ,fFoilThick(s.fFoilThick)
151 ,fGapThick(s.fGapThick)
152 ,fFoilDens(s.fFoilDens)
153 ,fGapDens(s.fGapDens)
154 ,fFoilOmega(s.fFoilOmega)
155 ,fGapOmega(s.fGapOmega)
161 ,fSpNBins(s.fSpNBins)
162 ,fSpRange(s.fSpRange)
163 ,fSpBinWidth(s.fSpBinWidth)
164 ,fSpLower(s.fSpLower)
165 ,fSpUpper(s.fSpUpper)
170 // AliTRDsim copy constructor
173 if (((AliTRDsim &) s).fNFoils) {
174 delete [] ((AliTRDsim &) s).fNFoils;
176 ((AliTRDsim &) s).fNFoils = new Int_t[fNFoilsDim];
177 for (Int_t iFoil = 0; iFoil < fNFoilsDim; iFoil++) {
178 ((AliTRDsim &) s).fNFoils[iFoil] = fNFoils[iFoil];
181 if (((AliTRDsim &) s).fNFoilsUp) {
182 delete [] ((AliTRDsim &) s).fNFoilsUp;
184 ((AliTRDsim &) s).fNFoilsUp = new Double_t[fNFoilsDim];
185 for (Int_t iFoil = 0; iFoil < fNFoilsDim; iFoil++) {
186 ((AliTRDsim &) s).fNFoilsUp[iFoil] = fNFoilsUp[iFoil];
189 if (((AliTRDsim &) s).fSigma) {
190 delete [] ((AliTRDsim &) s).fSigma;
192 ((AliTRDsim &) s).fSigma = new Double_t[fSpNBins];
193 for (Int_t iBin = 0; iBin < fSpNBins; iBin++) {
194 ((AliTRDsim &) s).fSigma[iBin] = fSigma[iBin];
197 fSpectrum->Copy(*((AliTRDsim &) s).fSpectrum);
201 //_____________________________________________________________________________
202 AliTRDsim::~AliTRDsim()
205 // AliTRDsim destructor
225 //_____________________________________________________________________________
226 AliTRDsim &AliTRDsim::operator=(const AliTRDsim &s)
229 // Assignment operator
232 if (this != &s) ((AliTRDsim &) s).Copy(*this);
238 //_____________________________________________________________________________
239 void AliTRDsim::Copy(TObject &s) const
245 ((AliTRDsim &) s).fFoilThick = fFoilThick;
246 ((AliTRDsim &) s).fFoilDens = fFoilDens;
247 ((AliTRDsim &) s).fFoilOmega = fFoilOmega;
248 ((AliTRDsim &) s).fFoilZ = fFoilZ;
249 ((AliTRDsim &) s).fFoilA = fFoilA;
250 ((AliTRDsim &) s).fGapThick = fGapThick;
251 ((AliTRDsim &) s).fGapDens = fGapDens;
252 ((AliTRDsim &) s).fGapOmega = fGapOmega;
253 ((AliTRDsim &) s).fGapZ = fGapZ;
254 ((AliTRDsim &) s).fGapA = fGapA;
255 ((AliTRDsim &) s).fTemp = fTemp;
256 ((AliTRDsim &) s).fSpNBins = fSpNBins;
257 ((AliTRDsim &) s).fSpRange = fSpRange;
258 ((AliTRDsim &) s).fSpBinWidth = fSpBinWidth;
259 ((AliTRDsim &) s).fSpLower = fSpLower;
260 ((AliTRDsim &) s).fSpUpper = fSpUpper;
262 if (((AliTRDsim &) s).fNFoils) {
263 delete [] ((AliTRDsim &) s).fNFoils;
265 ((AliTRDsim &) s).fNFoils = new Int_t[fNFoilsDim];
266 for (Int_t iFoil = 0; iFoil < fNFoilsDim; iFoil++) {
267 ((AliTRDsim &) s).fNFoils[iFoil] = fNFoils[iFoil];
270 if (((AliTRDsim &) s).fNFoilsUp) {
271 delete [] ((AliTRDsim &) s).fNFoilsUp;
273 ((AliTRDsim &) s).fNFoilsUp = new Double_t[fNFoilsDim];
274 for (Int_t iFoil = 0; iFoil < fNFoilsDim; iFoil++) {
275 ((AliTRDsim &) s).fNFoilsUp[iFoil] = fNFoilsUp[iFoil];
278 if (((AliTRDsim &) s).fSigma) {
279 delete [] ((AliTRDsim &) s).fSigma;
281 ((AliTRDsim &) s).fSigma = new Double_t[fSpNBins];
282 for (Int_t iBin = 0; iBin < fSpNBins; iBin++) {
283 ((AliTRDsim &) s).fSigma[iBin] = fSigma[iBin];
286 fSpectrum->Copy(*((AliTRDsim &) s).fSpectrum);
290 //_____________________________________________________________________________
291 void AliTRDsim::Init()
295 // The default radiator are prolypropilene foils of 10 mu thickness
296 // with gaps of 80 mu filled with N2.
304 fNFoils = new Int_t[fNFoilsDim];
316 fNFoilsUp = new Double_t[fNFoilsDim];
323 fNFoilsUp[6] = 10000.0;
329 fFoilOmega = Omega(fFoilDens,fFoilZ,fFoilA);
335 fGapOmega = Omega(fGapDens ,fGapZ ,fGapA );
341 fSpBinWidth = fSpRange / fSpNBins;
342 fSpLower = 1.0 - 0.5 * fSpBinWidth;
343 fSpUpper = fSpLower + fSpRange;
345 if (fSpectrum) delete fSpectrum;
346 fSpectrum = new TH1D("TRspectrum","TR spectrum",fSpNBins,fSpLower,fSpUpper);
347 fSpectrum->SetDirectory(0);
349 // Set the sigma values
354 //_____________________________________________________________________________
355 Int_t AliTRDsim::CreatePhotons(Int_t pdg, Float_t p
356 , Int_t &nPhoton, Float_t *ePhoton)
359 // Create TRD photons for a charged particle of type <pdg> with the total
361 // Number of produced TR photons: <nPhoton>
362 // Energies of the produced TR photons: <ePhoton>
366 const Int_t kPdgEle = 11;
367 const Int_t kPdgMuon = 13;
368 const Int_t kPdgPion = 211;
369 const Int_t kPdgKaon = 321;
372 switch (TMath::Abs(pdg)) {
390 // Calculate the TR photons
391 return TrPhotons(p, mass, nPhoton, ePhoton);
395 //_____________________________________________________________________________
396 Int_t AliTRDsim::TrPhotons(Float_t p, Float_t mass
397 , Int_t &nPhoton, Float_t *ePhoton)
400 // Produces TR photons using a parametric model for regular radiator. Photons
401 // with energy larger than 15 keV are included in the MC stack and tracked by VMC
405 // p - parent momentum [GeV/c]
406 // mass - parent mass
409 // nPhoton - number of photons which have to be processed by custom code
410 // ePhoton - energy of this photons in keV.
413 const Double_t kAlpha = 0.0072973;
414 const Int_t kSumMax = 30;
416 Double_t tau = fGapThick / fFoilThick;
419 Double_t gamma = TMath::Sqrt(p*p + mass*mass) / mass;
421 // Select the number of foils corresponding to momentum
422 Int_t foils = SelectNFoils(p);
438 for (Int_t iBin = 1; iBin <= fSpNBins; iBin++) {
440 energykeV = fSpectrum->GetBinCenter(iBin);
441 energyeV = energykeV * 1.0e3;
443 sigma = Sigma(energykeV);
445 csi1 = fFoilOmega / energyeV;
446 csi2 = fGapOmega / energyeV;
448 rho1 = 2.5 * energyeV * fFoilThick * 1.0e4
449 * (1.0 / (gamma*gamma) + csi1*csi1);
450 rho2 = 2.5 * energyeV * fFoilThick * 1.0e4
451 * (1.0 / (gamma*gamma) + csi2 *csi2);
455 for (Int_t n = 1; n <= kSumMax; n++) {
456 thetaN = (TMath::Pi() * 2.0 * n - (rho1 + tau * rho2)) / (1.0 + tau);
460 aux = 1.0 / (rho1 + thetaN) - 1.0 / (rho2 + thetaN);
461 sum += thetaN * (aux*aux) * (1.0 - TMath::Cos(rho1 + thetaN));
464 // Equivalent number of foils
465 nEqu = (1.0 - TMath::Exp(-foils * sigma)) / (1.0 - TMath::Exp(-sigma));
468 fSpectrum->SetBinContent(iBin,4.0 * kAlpha * nEqu * sum / (energykeV * (1.0 + tau)));
472 // <nTR> (binsize corr.)
473 Float_t nTr = fSpBinWidth * fSpectrum->Integral();
474 // Number of TR photons from Poisson distribution with mean <nTr>
475 Int_t nPhCand = gRandom->Poisson(nTr);
477 // Link the MC stack and get info about parent electron
478 TVirtualMCStack *stack = gMC->GetStack();
479 TParticle *trGenerator = stack->GetCurrentTrack();
480 Int_t track = stack->GetCurrentTrackNumber();
481 Double_t px = trGenerator->Px() / trGenerator->P();
482 Double_t py = trGenerator->Py() / trGenerator->P();
483 Double_t pz = trGenerator->Pz() / trGenerator->P();
485 // Current position of electron
489 gMC->TrackPosition(x,y,z);
491 // Counter for TR analysed in custom code (e < 15keV)
494 for (Int_t iPhoton = 0; iPhoton < nPhCand; iPhoton++) {
496 // Energy of the TR photon
497 Double_t e = fSpectrum->GetRandom();
499 // Put TR photon on particle stack
502 e *= 1.0e-6; // Convert it to GeV
505 stack-> PushTrack(1 // Must be 1
506 ,track // Identifier of the parent track, -1 for a primary
507 ,22 // Particle code.
508 ,px*e // 4 momentum (The photon is generated on the same
509 ,py*e // direction as the parent. For irregular radiator one
510 ,pz*e // can calculate also the angle but this is a secondary
512 ,x,y,z,0.0 // 4 vertex
513 ,0.0,0.0,0.0 // Polarisation
514 ,kPFeedBackPhoton // Production mechanism (there is no TR in G3 so one
515 // has to make some convention)
516 ,phtrack // On output the number of the track stored
521 // Custom treatment of TR photons
524 ePhoton[nPhoton++] = e;
534 //_____________________________________________________________________________
535 void AliTRDsim::SetSigma()
538 // Sets the absorbtion crosssection for the energies of the TR spectrum
544 fSigma = new Double_t[fSpNBins];
546 for (Int_t iBin = 0; iBin < fSpNBins; iBin++) {
547 Double_t energykeV = iBin * fSpBinWidth + 1.0;
548 fSigma[iBin] = Sigma(energykeV);
553 //_____________________________________________________________________________
554 Double_t AliTRDsim::Sigma(Double_t energykeV)
557 // Calculates the absorbtion crosssection for a one-foil-one-gap-radiator
561 Double_t energyMeV = energykeV * 0.001;
562 if (energyMeV >= 0.001) {
563 return(GetMuPo(energyMeV) * fFoilDens * fFoilThick +
564 GetMuAi(energyMeV) * fGapDens * fGapThick * GetTemp());
572 //_____________________________________________________________________________
573 Double_t AliTRDsim::GetMuPo(Double_t energyMeV)
576 // Returns the photon absorbtion cross section for polypropylene
581 Double_t mu[kN] = { 1.894E+03, 5.999E+02, 2.593E+02
582 , 7.743E+01, 3.242E+01, 1.643E+01
583 , 9.432E+00, 3.975E+00, 2.088E+00
584 , 7.452E-01, 4.315E-01, 2.706E-01
585 , 2.275E-01, 2.084E-01, 1.970E-01
586 , 1.823E-01, 1.719E-01, 1.534E-01
587 , 1.402E-01, 1.217E-01, 1.089E-01
588 , 9.947E-02, 9.198E-02, 8.078E-02
589 , 7.262E-02, 6.495E-02, 5.910E-02
590 , 5.064E-02, 4.045E-02, 3.444E-02
591 , 3.045E-02, 2.760E-02, 2.383E-02
592 , 2.145E-02, 1.819E-02, 1.658E-02 };
594 Double_t en[kN] = { 1.000E-03, 1.500E-03, 2.000E-03
595 , 3.000E-03, 4.000E-03, 5.000E-03
596 , 6.000E-03, 8.000E-03, 1.000E-02
597 , 1.500E-02, 2.000E-02, 3.000E-02
598 , 4.000E-02, 5.000E-02, 6.000E-02
599 , 8.000E-02, 1.000E-01, 1.500E-01
600 , 2.000E-01, 3.000E-01, 4.000E-01
601 , 5.000E-01, 6.000E-01, 8.000E-01
602 , 1.000E+00, 1.250E+00, 1.500E+00
603 , 2.000E+00, 3.000E+00, 4.000E+00
604 , 5.000E+00, 6.000E+00, 8.000E+00
605 , 1.000E+01, 1.500E+01, 2.000E+01 };
607 return Interpolate(energyMeV,en,mu,kN);
611 //_____________________________________________________________________________
612 Double_t AliTRDsim::GetMuCO(Double_t energyMeV)
615 // Returns the photon absorbtion cross section for CO2
620 Double_t mu[kN] = { 0.39383E+04, 0.13166E+04, 0.58750E+03
621 , 0.18240E+03, 0.77996E+02, 0.40024E+02
622 , 0.23116E+02, 0.96997E+01, 0.49726E+01
623 , 0.15543E+01, 0.74915E+00, 0.34442E+00
624 , 0.24440E+00, 0.20589E+00, 0.18632E+00
625 , 0.16578E+00, 0.15394E+00, 0.13558E+00
626 , 0.12336E+00, 0.10678E+00, 0.95510E-01
627 , 0.87165E-01, 0.80587E-01, 0.70769E-01
628 , 0.63626E-01, 0.56894E-01, 0.51782E-01
629 , 0.44499E-01, 0.35839E-01, 0.30825E-01
630 , 0.27555E-01, 0.25269E-01, 0.22311E-01
631 , 0.20516E-01, 0.18184E-01, 0.17152E-01 };
633 Double_t en[kN] = { 0.10000E-02, 0.15000E-02, 0.20000E-02
634 , 0.30000E-02, 0.40000E-02, 0.50000E-02
635 , 0.60000E-02, 0.80000E-02, 0.10000E-01
636 , 0.15000E-01, 0.20000E-01, 0.30000E-01
637 , 0.40000E-01, 0.50000E-01, 0.60000E-01
638 , 0.80000E-01, 0.10000E+00, 0.15000E+00
639 , 0.20000E+00, 0.30000E+00, 0.40000E+00
640 , 0.50000E+00, 0.60000E+00, 0.80000E+00
641 , 0.10000E+01, 0.12500E+01, 0.15000E+01
642 , 0.20000E+01, 0.30000E+01, 0.40000E+01
643 , 0.50000E+01, 0.60000E+01, 0.80000E+01
644 , 0.10000E+02, 0.15000E+02, 0.20000E+02 };
646 return Interpolate(energyMeV,en,mu,kN);
650 //_____________________________________________________________________________
651 Double_t AliTRDsim::GetMuXe(Double_t energyMeV)
654 // Returns the photon absorbtion cross section for xenon
659 Double_t mu[kN] = { 9.413E+03, 8.151E+03, 7.035E+03
660 , 7.338E+03, 4.085E+03, 2.088E+03
661 , 7.780E+02, 3.787E+02, 2.408E+02
662 , 6.941E+02, 6.392E+02, 6.044E+02
663 , 8.181E+02, 7.579E+02, 6.991E+02
664 , 8.064E+02, 6.376E+02, 3.032E+02
665 , 1.690E+02, 5.743E+01, 2.652E+01
666 , 8.930E+00, 6.129E+00, 3.316E+01
667 , 2.270E+01, 1.272E+01, 7.825E+00
668 , 3.633E+00, 2.011E+00, 7.202E-01
669 , 3.760E-01, 1.797E-01, 1.223E-01
670 , 9.699E-02, 8.281E-02, 6.696E-02
671 , 5.785E-02, 5.054E-02, 4.594E-02
672 , 4.078E-02, 3.681E-02, 3.577E-02
673 , 3.583E-02, 3.634E-02, 3.797E-02
674 , 3.987E-02, 4.445E-02, 4.815E-02 };
676 Double_t en[kN] = { 1.00000E-03, 1.07191E-03, 1.14900E-03
677 , 1.14900E-03, 1.50000E-03, 2.00000E-03
678 , 3.00000E-03, 4.00000E-03, 4.78220E-03
679 , 4.78220E-03, 5.00000E-03, 5.10370E-03
680 , 5.10370E-03, 5.27536E-03, 5.45280E-03
681 , 5.45280E-03, 6.00000E-03, 8.00000E-03
682 , 1.00000E-02, 1.50000E-02, 2.00000E-02
683 , 3.00000E-02, 3.45614E-02, 3.45614E-02
684 , 4.00000E-02, 5.00000E-02, 6.00000E-02
685 , 8.00000E-02, 1.00000E-01, 1.50000E-01
686 , 2.00000E-01, 3.00000E-01, 4.00000E-01
687 , 5.00000E-01, 6.00000E-01, 8.00000E-01
688 , 1.00000E+00, 1.25000E+00, 1.50000E+00
689 , 2.00000E+00, 3.00000E+00, 4.00000E+00
690 , 5.00000E+00, 6.00000E+00, 8.00000E+00
691 , 1.00000E+01, 1.50000E+01, 2.00000E+01 };
693 return Interpolate(energyMeV,en,mu,kN);
697 //_____________________________________________________________________________
698 Double_t AliTRDsim::GetMuBu(Double_t energyMeV)
701 // Returns the photon absorbtion cross section for isobutane
706 Double_t mu[kN] = { 0.38846E+03, 0.12291E+03, 0.53225E+02
707 , 0.16091E+02, 0.69114E+01, 0.36541E+01
708 , 0.22282E+01, 0.11149E+01, 0.72887E+00
709 , 0.45053E+00, 0.38167E+00, 0.33920E+00
710 , 0.32155E+00, 0.30949E+00, 0.29960E+00
711 , 0.28317E+00, 0.26937E+00, 0.24228E+00
712 , 0.22190E+00, 0.19289E+00, 0.17288E+00
713 , 0.15789E+00, 0.14602E+00, 0.12829E+00
714 , 0.11533E+00, 0.10310E+00, 0.93790E-01
715 , 0.80117E-01, 0.63330E-01, 0.53229E-01
716 , 0.46390E-01, 0.41425E-01, 0.34668E-01
717 , 0.30267E-01, 0.23910E-01, 0.20509E-01 };
719 Double_t en[kN] = { 0.10000E-02, 0.15000E-02, 0.20000E-02
720 , 0.30000E-02, 0.40000E-02, 0.50000E-02
721 , 0.60000E-02, 0.80000E-02, 0.10000E-01
722 , 0.15000E-01, 0.20000E-01, 0.30000E-01
723 , 0.40000E-01, 0.50000E-01, 0.60000E-01
724 , 0.80000E-01, 0.10000E+00, 0.15000E+00
725 , 0.20000E+00, 0.30000E+00, 0.40000E+00
726 , 0.50000E+00, 0.60000E+00, 0.80000E+00
727 , 0.10000E+01, 0.12500E+01, 0.15000E+01
728 , 0.20000E+01, 0.30000E+01, 0.40000E+01
729 , 0.50000E+01, 0.60000E+01, 0.80000E+01
730 , 0.10000E+02, 0.15000E+02, 0.20000E+02 };
732 return Interpolate(energyMeV,en,mu,kN);
736 //_____________________________________________________________________________
737 Double_t AliTRDsim::GetMuMy(Double_t energyMeV)
740 // Returns the photon absorbtion cross section for mylar
745 Double_t mu[kN] = { 2.911E+03, 9.536E+02, 4.206E+02
746 , 1.288E+02, 5.466E+01, 2.792E+01
747 , 1.608E+01, 6.750E+00, 3.481E+00
748 , 1.132E+00, 5.798E-01, 3.009E-01
749 , 2.304E-01, 2.020E-01, 1.868E-01
750 , 1.695E-01, 1.586E-01, 1.406E-01
751 , 1.282E-01, 1.111E-01, 9.947E-02
752 , 9.079E-02, 8.395E-02, 7.372E-02
753 , 6.628E-02, 5.927E-02, 5.395E-02
754 , 4.630E-02, 3.715E-02, 3.181E-02
755 , 2.829E-02, 2.582E-02, 2.257E-02
756 , 2.057E-02, 1.789E-02, 1.664E-02 };
758 Double_t en[kN] = { 1.00000E-03, 1.50000E-03, 2.00000E-03
759 , 3.00000E-03, 4.00000E-03, 5.00000E-03
760 , 6.00000E-03, 8.00000E-03, 1.00000E-02
761 , 1.50000E-02, 2.00000E-02, 3.00000E-02
762 , 4.00000E-02, 5.00000E-02, 6.00000E-02
763 , 8.00000E-02, 1.00000E-01, 1.50000E-01
764 , 2.00000E-01, 3.00000E-01, 4.00000E-01
765 , 5.00000E-01, 6.00000E-01, 8.00000E-01
766 , 1.00000E+00, 1.25000E+00, 1.50000E+00
767 , 2.00000E+00, 3.00000E+00, 4.00000E+00
768 , 5.00000E+00, 6.00000E+00, 8.00000E+00
769 , 1.00000E+01, 1.50000E+01, 2.00000E+01 };
771 return Interpolate(energyMeV,en,mu,kN);
775 //_____________________________________________________________________________
776 Double_t AliTRDsim::GetMuN2(Double_t energyMeV)
779 // Returns the photon absorbtion cross section for nitrogen
784 Double_t mu[kN] = { 3.311E+03, 1.083E+03, 4.769E+02
785 , 1.456E+02, 6.166E+01, 3.144E+01
786 , 1.809E+01, 7.562E+00, 3.879E+00
787 , 1.236E+00, 6.178E-01, 3.066E-01
788 , 2.288E-01, 1.980E-01, 1.817E-01
789 , 1.639E-01, 1.529E-01, 1.353E-01
790 , 1.233E-01, 1.068E-01, 9.557E-02
791 , 8.719E-02, 8.063E-02, 7.081E-02
792 , 6.364E-02, 5.693E-02, 5.180E-02
793 , 4.450E-02, 3.579E-02, 3.073E-02
794 , 2.742E-02, 2.511E-02, 2.209E-02
795 , 2.024E-02, 1.782E-02, 1.673E-02 };
797 Double_t en[kN] = { 1.00000E-03, 1.50000E-03, 2.00000E-03
798 , 3.00000E-03, 4.00000E-03, 5.00000E-03
799 , 6.00000E-03, 8.00000E-03, 1.00000E-02
800 , 1.50000E-02, 2.00000E-02, 3.00000E-02
801 , 4.00000E-02, 5.00000E-02, 6.00000E-02
802 , 8.00000E-02, 1.00000E-01, 1.50000E-01
803 , 2.00000E-01, 3.00000E-01, 4.00000E-01
804 , 5.00000E-01, 6.00000E-01, 8.00000E-01
805 , 1.00000E+00, 1.25000E+00, 1.50000E+00
806 , 2.00000E+00, 3.00000E+00, 4.00000E+00
807 , 5.00000E+00, 6.00000E+00, 8.00000E+00
808 , 1.00000E+01, 1.50000E+01, 2.00000E+01 };
810 return Interpolate(energyMeV,en,mu,kN);
814 //_____________________________________________________________________________
815 Double_t AliTRDsim::GetMuO2(Double_t energyMeV)
818 // Returns the photon absorbtion cross section for oxygen
823 Double_t mu[kN] = { 4.590E+03, 1.549E+03, 6.949E+02
824 , 2.171E+02, 9.315E+01, 4.790E+01
825 , 2.770E+01, 1.163E+01, 5.952E+00
826 , 1.836E+00, 8.651E-01, 3.779E-01
827 , 2.585E-01, 2.132E-01, 1.907E-01
828 , 1.678E-01, 1.551E-01, 1.361E-01
829 , 1.237E-01, 1.070E-01, 9.566E-02
830 , 8.729E-02, 8.070E-02, 7.087E-02
831 , 6.372E-02, 5.697E-02, 5.185E-02
832 , 4.459E-02, 3.597E-02, 3.100E-02
833 , 2.777E-02, 2.552E-02, 2.263E-02
834 , 2.089E-02, 1.866E-02, 1.770E-02 };
836 Double_t en[kN] = { 1.00000E-03, 1.50000E-03, 2.00000E-03
837 , 3.00000E-03, 4.00000E-03, 5.00000E-03
838 , 6.00000E-03, 8.00000E-03, 1.00000E-02
839 , 1.50000E-02, 2.00000E-02, 3.00000E-02
840 , 4.00000E-02, 5.00000E-02, 6.00000E-02
841 , 8.00000E-02, 1.00000E-01, 1.50000E-01
842 , 2.00000E-01, 3.00000E-01, 4.00000E-01
843 , 5.00000E-01, 6.00000E-01, 8.00000E-01
844 , 1.00000E+00, 1.25000E+00, 1.50000E+00
845 , 2.00000E+00, 3.00000E+00, 4.00000E+00
846 , 5.00000E+00, 6.00000E+00, 8.00000E+00
847 , 1.00000E+01, 1.50000E+01, 2.00000E+01 };
849 return Interpolate(energyMeV,en,mu,kN);
853 //_____________________________________________________________________________
854 Double_t AliTRDsim::GetMuHe(Double_t energyMeV)
857 // Returns the photon absorbtion cross section for helium
862 Double_t mu[kN] = { 6.084E+01, 1.676E+01, 6.863E+00
863 , 2.007E+00, 9.329E-01, 5.766E-01
864 , 4.195E-01, 2.933E-01, 2.476E-01
865 , 2.092E-01, 1.960E-01, 1.838E-01
866 , 1.763E-01, 1.703E-01, 1.651E-01
867 , 1.562E-01, 1.486E-01, 1.336E-01
868 , 1.224E-01, 1.064E-01, 9.535E-02
869 , 8.707E-02, 8.054E-02, 7.076E-02
870 , 6.362E-02, 5.688E-02, 5.173E-02
871 , 4.422E-02, 3.503E-02, 2.949E-02
872 , 2.577E-02, 2.307E-02, 1.940E-02
873 , 1.703E-02, 1.363E-02, 1.183E-02 };
875 Double_t en[kN] = { 1.00000E-03, 1.50000E-03, 2.00000E-03
876 , 3.00000E-03, 4.00000E-03, 5.00000E-03
877 , 6.00000E-03, 8.00000E-03, 1.00000E-02
878 , 1.50000E-02, 2.00000E-02, 3.00000E-02
879 , 4.00000E-02, 5.00000E-02, 6.00000E-02
880 , 8.00000E-02, 1.00000E-01, 1.50000E-01
881 , 2.00000E-01, 3.00000E-01, 4.00000E-01
882 , 5.00000E-01, 6.00000E-01, 8.00000E-01
883 , 1.00000E+00, 1.25000E+00, 1.50000E+00
884 , 2.00000E+00, 3.00000E+00, 4.00000E+00
885 , 5.00000E+00, 6.00000E+00, 8.00000E+00
886 , 1.00000E+01, 1.50000E+01, 2.00000E+01 };
888 return Interpolate(energyMeV,en,mu,kN);
892 //_____________________________________________________________________________
893 Double_t AliTRDsim::GetMuAi(Double_t energyMeV)
896 // Returns the photon absorbtion cross section for air
897 // Implemented by Oliver Busch
902 Double_t mu[kN] = { 0.35854E+04, 0.11841E+04, 0.52458E+03,
903 0.16143E+03, 0.14250E+03, 0.15722E+03,
904 0.77538E+02, 0.40099E+02, 0.23313E+02,
905 0.98816E+01, 0.51000E+01, 0.16079E+01,
906 0.77536E+00, 0.35282E+00, 0.24790E+00,
907 0.20750E+00, 0.18703E+00, 0.16589E+00,
908 0.15375E+00, 0.13530E+00, 0.12311E+00,
909 0.10654E+00, 0.95297E-01, 0.86939E-01,
910 0.80390E-01, 0.70596E-01, 0.63452E-01,
911 0.56754E-01, 0.51644E-01, 0.44382E-01,
912 0.35733E-01, 0.30721E-01, 0.27450E-01,
913 0.25171E-01, 0.22205E-01, 0.20399E-01,
914 0.18053E-01, 0.18057E-01 };
918 Double_t en[kN] = { 0.10000E-02, 0.15000E-02, 0.20000E-02,
919 0.30000E-02, 0.32029E-02, 0.32029E-02,
920 0.40000E-02, 0.50000E-02, 0.60000E-02,
921 0.80000E-02, 0.10000E-01, 0.15000E-01,
922 0.20000E-01, 0.30000E-01, 0.40000E-01,
923 0.50000E-01, 0.60000E-01, 0.80000E-01,
924 0.10000E+00, 0.15000E+00, 0.20000E+00,
925 0.30000E+00, 0.40000E+00, 0.50000E+00,
926 0.60000E+00, 0.80000E+00, 0.10000E+01,
927 0.12500E+01, 0.15000E+01, 0.20000E+01,
928 0.30000E+01, 0.40000E+01, 0.50000E+01,
929 0.60000E+01, 0.80000E+01, 0.10000E+02,
930 0.15000E+02, 0.20000E+02 };
932 return Interpolate(energyMeV,en,mu,kN);
936 //_____________________________________________________________________________
937 Double_t AliTRDsim::Interpolate(Double_t energyMeV
938 , Double_t *en, Double_t *mu, Int_t n)
941 // Interpolates the photon absorbtion cross section
942 // for a given energy <energyMeV>.
947 Int_t istat = Locate(en,n,energyMeV,index,de);
949 return (mu[index] - de * (mu[index] - mu[index+1])
950 / (en[index+1] - en[index] ));
958 //_____________________________________________________________________________
959 Int_t AliTRDsim::Locate(Double_t *xv, Int_t n, Double_t xval
960 , Int_t &kl, Double_t &dx)
963 // Locates a point (xval) in a 1-dim grid (xv(n))
966 if (xval >= xv[n-1]) {
977 while (kh - kl > 1) {
978 if (xval < xv[km = (kl+kh)/2]) {
985 if ((xval < xv[kl]) ||
988 AliFatal(Form("Locate failed xv[%d] %f xval %f xv[%d] %f!!!\n"
989 ,kl,xv[kl],xval,kl+1,xv[kl+1]));
999 //_____________________________________________________________________________
1000 Int_t AliTRDsim::SelectNFoils(Float_t p)
1003 // Selects the number of foils corresponding to the momentum
1006 Int_t foils = fNFoils[fNFoilsDim-1];
1008 for (Int_t iFoil = 0; iFoil < fNFoilsDim; iFoil++) {
1009 if (p < fNFoilsUp[iFoil]) {
1010 foils = fNFoils[iFoil];