1 /**************************************************************************
2 * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
4 * Author: The ALICE Off-line Project. *
5 * Contributors are mentioned in the code where appropriate. *
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 **************************************************************************/
18 ////////////////////////////////////////////////////////////////////////////
20 // Transition Radiation Detector version 1 -- slow simulator //
22 ////////////////////////////////////////////////////////////////////////////
27 #include <TLorentzVector.h>
31 #include <TVirtualMC.h>
32 #include <TGeoManager.h>
39 #include "AliTRDgeometry.h"
40 #include "AliTRDhit.h"
41 #include "AliTRDsim.h"
46 //_____________________________________________________________________________
51 ,fTypeOfStepManager(0)
59 // Default constructor
64 //_____________________________________________________________________________
65 AliTRDv1::AliTRDv1(const char *name, const char *title)
69 ,fTypeOfStepManager(2)
77 // Standard constructor for Transition Radiation Detector version 1
80 SetBufferSize(128000);
84 //_____________________________________________________________________________
88 // AliTRDv1 destructor
108 //_____________________________________________________________________________
109 void AliTRDv1::AddAlignableVolumes() const
112 // Create entries for alignable volumes associating the symbolic volume
113 // name with the corresponding volume path. Needs to be syncronized with
114 // eventual changes in the geometry.
120 TString vpStr = "ALIC_1/B077_1/BSEGMO";
121 TString vpApp1 = "_1/BTRD";
122 TString vpApp2 = "_1";
123 TString vpApp3 = "/UTR1_1/UTS1_1/UTI1_1/UT";
125 TString snStr = "TRD/sm";
126 TString snApp1 = "/st";
127 TString snApp2 = "/pl";
131 // The symbolic names are: TRD/sm00
135 for (Int_t isect = 0; isect < AliTRDgeometry::Nsect(); isect++) {
144 symName += Form("%02d",isect);
146 gGeoManager->SetAlignableEntry(symName.Data(),volPath.Data());
151 // The readout chambers
152 // The symbolic names are: TRD/sm00/st0/pl0
156 for (Int_t isect = 0; isect < AliTRDgeometry::Nsect(); isect++) {
157 for (Int_t icham = 0; icham < AliTRDgeometry::Ncham(); icham++) {
158 for (Int_t iplan = 0; iplan < AliTRDgeometry::Nplan(); iplan++) {
160 Int_t idet = AliTRDgeometry::GetDetectorSec(iplan,icham);
168 volPath += Form("%02d",idet);
172 symName += Form("%02d",isect);
178 gGeoManager->SetAlignableEntry(symName.Data(),volPath.Data());
186 //_____________________________________________________________________________
187 void AliTRDv1::CreateGeometry()
190 // Create the GEANT geometry for the Transition Radiation Detector - Version 1
191 // This version covers the full azimuth.
194 // Check that FRAME is there otherwise we have no place where to put the TRD
195 AliModule* frame = gAlice->GetModule("FRAME");
197 AliError("TRD needs FRAME to be present\n");
201 // Define the chambers
202 AliTRD::CreateGeometry();
206 //_____________________________________________________________________________
207 void AliTRDv1::CreateMaterials()
210 // Create materials for the Transition Radiation Detector version 1
213 AliTRD::CreateMaterials();
217 //_____________________________________________________________________________
218 void AliTRDv1::CreateTRhit(Int_t det)
221 // Creates an electron cluster from a TR photon.
222 // The photon is assumed to be created a the end of the radiator. The
223 // distance after which it deposits its energy takes into account the
224 // absorbtion of the entrance window and of the gas mixture in drift
229 const Int_t kPdgElectron = 11;
232 const Float_t kWion = 23.53;
234 // Maximum number of TR photons per track
235 const Int_t kNTR = 50;
240 // Create TR at the entrance of the chamber
241 if (gMC->IsTrackEntering()) {
243 // Create TR only for electrons
244 Int_t iPdg = gMC->TrackPid();
245 if (TMath::Abs(iPdg) != kPdgElectron) {
253 gMC->TrackMomentum(mom);
254 Float_t pTot = mom.Rho();
255 fTR->CreatePhotons(iPdg,pTot,nTR,eTR);
257 AliFatal(Form("Boundary error: nTR = %d, kNTR = %d",nTR,kNTR));
260 // Loop through the TR photons
261 for (Int_t iTR = 0; iTR < nTR; iTR++) {
263 Float_t energyMeV = eTR[iTR] * 0.001;
264 Float_t energyeV = eTR[iTR] * 1000.0;
265 Float_t absLength = 0.0;
268 // Take the absorbtion in the entrance window into account
269 Double_t muMy = fTR->GetMuMy(energyMeV);
270 sigma = muMy * fFoilDensity;
272 absLength = gRandom->Exp(1.0/sigma);
273 if (absLength < AliTRDgeometry::MyThick()) {
281 // The absorbtion cross sections in the drift gas
282 // Gas-mixture (Xe/CO2)
283 Double_t muXe = fTR->GetMuXe(energyMeV);
284 Double_t muCO = fTR->GetMuCO(energyMeV);
285 sigma = (0.85 * muXe + 0.15 * muCO) * fGasDensity * fTR->GetTemp();
287 // The distance after which the energy of the TR photon
290 absLength = gRandom->Exp(1.0/sigma);
291 if (absLength > (AliTRDgeometry::DrThick()
292 + AliTRDgeometry::AmThick())) {
300 // The position of the absorbtion
302 gMC->TrackPosition(pos);
303 posHit[0] = pos[0] + mom[0] / pTot * absLength;
304 posHit[1] = pos[1] + mom[1] / pTot * absLength;
305 posHit[2] = pos[2] + mom[2] / pTot * absLength;
308 Int_t q = ((Int_t) (energyeV / kWion));
310 // Add the hit to the array. TR photon hits are marked
311 // by negative charge
312 AddHit(gAlice->GetMCApp()->GetCurrentTrackNumber()
324 //_____________________________________________________________________________
325 void AliTRDv1::Init()
328 // Initialise Transition Radiation Detector after geometry has been built.
333 AliDebug(1,"Slow simulator\n");
335 // Switch on TR simulation as default
337 AliInfo("TR simulation off");
340 fTR = new AliTRDsim();
343 // First ionization potential (eV) for the gas mixture (90% Xe + 10% CO2)
344 const Float_t kPoti = 12.1;
345 // Maximum energy (50 keV);
346 const Float_t kEend = 50000.0;
347 // Ermilova distribution for the delta-ray spectrum
348 Float_t poti = TMath::Log(kPoti);
349 Float_t eEnd = TMath::Log(kEend);
351 // Ermilova distribution for the delta-ray spectrum
352 fDeltaE = new TF1("deltae" ,Ermilova ,poti,eEnd,0);
354 // Geant3 distribution for the delta-ray spectrum
355 fDeltaG = new TF1("deltag",IntSpecGeant,2.421257,28.536469,0);
357 AliDebug(1,"+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++");
361 //_____________________________________________________________________________
362 void AliTRDv1::StepManager()
365 // Slow simulator. Every charged track produces electron cluster as hits
366 // along its path across the drift volume.
369 switch (fTypeOfStepManager) {
371 StepManagerErmilova();
377 StepManagerFixedStep();
380 AliWarning("Not a valid Step Manager.");
385 //_____________________________________________________________________________
386 void AliTRDv1::SelectStepManager(Int_t t)
389 // Selects a step manager type:
392 // 2 - Fixed step size
395 fTypeOfStepManager = t;
396 AliInfo(Form("Step Manager type %d was selected",fTypeOfStepManager));
400 //_____________________________________________________________________________
401 void AliTRDv1::StepManagerGeant()
404 // Slow simulator. Every charged track produces electron cluster as hits
405 // along its path across the drift volume. The step size is set acording
406 // to Bethe-Bloch. The energy distribution of the delta electrons follows
407 // a spectrum taken from Geant3.
409 // Version by A. Bercuci
427 Double_t stepSize = 0;
429 Bool_t drRegion = kFALSE;
430 Bool_t amRegion = kFALSE;
433 TString cIdSensDr = "J";
434 TString cIdSensAm = "K";
435 Char_t cIdChamber[3];
443 const Int_t kNplan = AliTRDgeometry::Nplan();
444 const Int_t kNcham = AliTRDgeometry::Ncham();
445 const Int_t kNdetsec = kNplan * kNcham;
447 const Double_t kBig = 1.0e+12; // Infinitely big
448 const Float_t kWion = 23.53; // Ionization energy
449 const Float_t kPTotMaxEl = 0.002; // Maximum momentum for e+ e- g
451 // Minimum energy for the step size adjustment
452 const Float_t kEkinMinStep = 1.0e-5;
453 // energy threshold for production of delta electrons
454 const Float_t kECut = 1.0e4;
455 // Parameters entering the parametrized range for delta electrons
456 const Float_t kRa = 5.37e-4;
457 const Float_t kRb = 0.9815;
458 const Float_t kRc = 3.123e-3;
459 // Gas density -> To be made user adjustable !
460 // [0.85*0.00549+0.15*0.00186 (Xe-CO2 85-15)]
461 const Float_t kRho = 0.004945 ;
463 // Plateau value of the energy-loss for electron in xenon
464 // The averaged value (26/3/99)
465 const Float_t kPlateau = 1.55;
466 // dN1/dx|min for the gas mixture (90% Xe + 10% CO2)
467 const Float_t kPrim = 19.34;
468 // First ionization potential (eV) for the gas mixture (90% Xe + 10% CO2)
469 const Float_t kPoti = 12.1;
471 const Int_t kPdgElectron = 11;
473 // Set the maximum step size to a very large number for all
474 // neutral particles and those outside the driftvolume
475 gMC->SetMaxStep(kBig);
477 // Use only charged tracks
478 if (( gMC->TrackCharge() ) &&
479 (!gMC->IsTrackDisappeared())) {
481 // Inside a sensitive volume?
484 cIdCurrent = gMC->CurrentVolName();
485 if (cIdSensDr == cIdCurrent[1]) {
488 if (cIdSensAm == cIdCurrent[1]) {
491 if (drRegion || amRegion) {
493 // The hit coordinates and charge
494 gMC->TrackPosition(pos);
499 // The sector number (0 - 17)
500 // The numbering goes clockwise and starts at y = 0
501 Float_t phi = kRaddeg*TMath::ATan2(pos[0],pos[1]);
508 sec = ((Int_t) (phi / 20.0));
510 // The plane and chamber number
511 cIdChamber[0] = cIdCurrent[2];
512 cIdChamber[1] = cIdCurrent[3];
513 Int_t idChamber = (atoi(cIdChamber) % kNdetsec);
514 cha = kNcham - ((Int_t) idChamber / kNplan) - 1;
515 pla = ((Int_t) idChamber % kNplan);
517 // Check on selected volumes
518 Int_t addthishit = 1;
523 // The detector number
524 det = fGeometry->GetDetector(pla,cha,sec);
526 // Special hits only in the drift region
529 // Create a track reference at the entrance and
530 // exit of each chamber that contain the
531 // momentum components of the particle
532 if (gMC->IsTrackEntering() ||
533 gMC->IsTrackExiting()) {
534 gMC->TrackMomentum(mom);
535 AddTrackReference(gAlice->GetMCApp()->GetCurrentTrackNumber());
538 if (gMC->IsTrackEntering() &&
539 !gMC->IsNewTrack()) {
540 // determine if hit belong to primary track
541 fPrimaryTrackPid = gAlice->GetMCApp()->GetCurrentTrackNumber();
542 // determine track length when entering the detector
543 fTrackLength0 = gMC->TrackLength();
546 // Create the hits from TR photons
547 if (fTR) CreateTRhit(det);
551 // Calculate the energy of the delta-electrons
552 // modified by Alex Bercuci (A.Bercuci@gsi.de) on 26.01.06
553 // take into account correlation with the underlying GEANT tracking
555 // http://www-linux.gsi.de/~abercuci/Contributions/TRD/index.html
557 // determine the most significant process (last on the processes list)
558 // which caused this hit
559 gMC->StepProcesses(processes);
560 Int_t nofprocesses = processes.GetSize();
566 pid = processes[nofprocesses-1];
569 // generate Edep according to GEANT parametrisation
570 eDelta = TMath::Exp(fDeltaG->GetRandom()) - kPoti;
571 eDelta = TMath::Max(eDelta,0.0);
572 Float_t prRange = 0.0;
573 Float_t range = gMC->TrackLength() - fTrackLength0;
574 // merge GEANT tracker information with locally cooked one
575 if (gAlice->GetMCApp()->GetCurrentTrackNumber() == fPrimaryTrackPid) {
577 if (eDelta >= kECut) {
578 prRange = kRa * eDelta * 0.001
579 * (1.0 - kRb / (1.0 + kRc * eDelta * 0.001)) / kRho;
580 if (prRange >= (3.7 - range)) {
586 if (eDelta < kECut) {
590 prRange = kRa * eDelta * 0.001
591 * (1.0 - kRb / (1.0 + kRc * eDelta * 0.001)) / kRho;
592 if (prRange >= ((AliTRDgeometry::DrThick()
593 + AliTRDgeometry::AmThick()) - range)) {
609 // Generate the electron cluster size
614 qTot = ((Int_t) (eDelta / kWion) + 1);
617 // Create a new dEdx hit
618 AddHit(gAlice->GetMCApp()->GetCurrentTrackNumber()
624 // Calculate the maximum step size for the next tracking step
625 // Produce only one hit if Ekin is below cutoff
626 aMass = gMC->TrackMass();
627 if ((gMC->Etot() - aMass) > kEkinMinStep) {
629 // The energy loss according to Bethe Bloch
630 iPdg = TMath::Abs(gMC->TrackPid());
631 if ((iPdg != kPdgElectron) ||
632 ((iPdg == kPdgElectron) &&
633 (pTot < kPTotMaxEl))) {
634 gMC->TrackMomentum(mom);
636 betaGamma = pTot / aMass;
637 pp = BetheBlochGeant(betaGamma);
638 // Take charge > 1 into account
639 charge = gMC->TrackCharge();
640 if (TMath::Abs(charge) > 1) {
641 pp = pp * charge*charge;
645 // Electrons above 20 Mev/c are at the plateau
646 pp = kPrim * kPlateau;
651 nsteps = gRandom->Poisson(pp);
653 stepSize = 1.0 / nsteps;
654 gMC->SetMaxStep(stepSize);
666 //_____________________________________________________________________________
667 void AliTRDv1::StepManagerErmilova()
670 // Slow simulator. Every charged track produces electron cluster as hits
671 // along its path across the drift volume. The step size is set acording
672 // to Bethe-Bloch. The energy distribution of the delta electrons follows
673 // a spectrum taken from Ermilova et al.
694 Bool_t drRegion = kFALSE;
695 Bool_t amRegion = kFALSE;
698 TString cIdSensDr = "J";
699 TString cIdSensAm = "K";
700 Char_t cIdChamber[3];
706 const Int_t kNplan = AliTRDgeometry::Nplan();
707 const Int_t kNcham = AliTRDgeometry::Ncham();
708 const Int_t kNdetsec = kNplan * kNcham;
710 const Double_t kBig = 1.0e+12; // Infinitely big
711 const Float_t kWion = 23.53; // Ionization energy
712 const Float_t kPTotMaxEl = 0.002; // Maximum momentum for e+ e- g
714 // Minimum energy for the step size adjustment
715 const Float_t kEkinMinStep = 1.0e-5;
717 // Plateau value of the energy-loss for electron in xenon
718 // The averaged value (26/3/99)
719 const Float_t kPlateau = 1.55;
720 // dN1/dx|min for the gas mixture (90% Xe + 10% CO2)
721 const Float_t kPrim = 48.0;
722 // First ionization potential (eV) for the gas mixture (90% Xe + 10% CO2)
723 const Float_t kPoti = 12.1;
725 const Int_t kPdgElectron = 11;
727 // Set the maximum step size to a very large number for all
728 // neutral particles and those outside the driftvolume
729 gMC->SetMaxStep(kBig);
731 // Use only charged tracks
732 if (( gMC->TrackCharge() ) &&
733 (!gMC->IsTrackDisappeared())) {
735 // Inside a sensitive volume?
738 cIdCurrent = gMC->CurrentVolName();
739 if (cIdSensDr == cIdCurrent[1]) {
742 if (cIdSensAm == cIdCurrent[1]) {
745 if (drRegion || amRegion) {
747 // The hit coordinates and charge
748 gMC->TrackPosition(pos);
753 // The sector number (0 - 17)
754 // The numbering goes clockwise and starts at y = 0
755 Float_t phi = kRaddeg*TMath::ATan2(pos[0],pos[1]);
762 sec = ((Int_t) (phi / 20.0));
764 // The plane and chamber number
765 cIdChamber[0] = cIdCurrent[2];
766 cIdChamber[1] = cIdCurrent[3];
767 Int_t idChamber = (atoi(cIdChamber) % kNdetsec);
768 cha = kNcham - ((Int_t) idChamber / kNplan) - 1;
769 pla = ((Int_t) idChamber % kNplan);
771 // Check on selected volumes
772 Int_t addthishit = 1;
777 // The detector number
778 det = fGeometry->GetDetector(pla,cha,sec);
780 // Special hits only in the drift region
783 // Create a track reference at the entrance and
784 // exit of each chamber that contain the
785 // momentum components of the particle
786 if (gMC->IsTrackEntering() ||
787 gMC->IsTrackExiting()) {
788 gMC->TrackMomentum(mom);
789 AddTrackReference(gAlice->GetMCApp()->GetCurrentTrackNumber());
791 // Create the hits from TR photons
798 // Calculate the energy of the delta-electrons
799 eDelta = TMath::Exp(fDeltaE->GetRandom()) - kPoti;
800 eDelta = TMath::Max(eDelta,0.0);
801 // Generate the electron cluster size
806 qTot = ((Int_t) (eDelta / kWion) + 1);
809 // Create a new dEdx hit
811 AddHit(gAlice->GetMCApp()->GetCurrentTrackNumber()
818 AddHit(gAlice->GetMCApp()->GetCurrentTrackNumber()
825 // Calculate the maximum step size for the next tracking step
826 // Produce only one hit if Ekin is below cutoff
827 aMass = gMC->TrackMass();
828 if ((gMC->Etot() - aMass) > kEkinMinStep) {
830 // The energy loss according to Bethe Bloch
831 iPdg = TMath::Abs(gMC->TrackPid());
832 if ((iPdg != kPdgElectron) ||
833 ((iPdg == kPdgElectron) &&
834 (pTot < kPTotMaxEl))) {
835 gMC->TrackMomentum(mom);
837 betaGamma = pTot / aMass;
838 pp = kPrim * BetheBloch(betaGamma);
839 // Take charge > 1 into account
840 charge = gMC->TrackCharge();
841 if (TMath::Abs(charge) > 1) {
842 pp = pp * charge*charge;
846 // Electrons above 20 Mev/c are at the plateau
847 pp = kPrim * kPlateau;
852 gMC->GetRandom()->RndmArray(1,random);
854 while ((random[0] == 1.0) ||
856 stepSize = - TMath::Log(random[0]) / pp;
857 gMC->SetMaxStep(stepSize);
870 //_____________________________________________________________________________
871 void AliTRDv1::StepManagerFixedStep()
874 // Slow simulator. Every charged track produces electron cluster as hits
875 // along its path across the drift volume. The step size is fixed in
876 // this version of the step manager.
888 Bool_t drRegion = kFALSE;
889 Bool_t amRegion = kFALSE;
892 TString cIdSensDr = "J";
893 TString cIdSensAm = "K";
894 Char_t cIdChamber[3];
900 const Int_t kNplan = AliTRDgeometry::Nplan();
901 const Int_t kNcham = AliTRDgeometry::Ncham();
902 const Int_t kNdetsec = kNplan * kNcham;
904 const Double_t kBig = 1.0e+12;
906 const Float_t kWion = 23.53; // Ionization energy
907 const Float_t kEkinMinStep = 1.0e-5; // Minimum energy for the step size adjustment
909 // Set the maximum step size to a very large number for all
910 // neutral particles and those outside the driftvolume
911 gMC->SetMaxStep(kBig);
913 // If not charged track or already stopped or disappeared, just return.
914 if ((!gMC->TrackCharge()) ||
915 gMC->IsTrackDisappeared()) return;
917 // Inside a sensitive volume?
918 cIdCurrent = gMC->CurrentVolName();
920 if (cIdSensDr == cIdCurrent[1]) drRegion = kTRUE;
921 if (cIdSensAm == cIdCurrent[1]) amRegion = kTRUE;
928 // The hit coordinates and charge
929 gMC->TrackPosition(pos);
934 // The sector number (0 - 17)
935 // The numbering goes clockwise and starts at y = 0
936 Float_t phi = kRaddeg*TMath::ATan2(pos[0],pos[1]);
943 sec = ((Int_t) (phi / 20.0));
945 // The plane and chamber number
946 cIdChamber[0] = cIdCurrent[2];
947 cIdChamber[1] = cIdCurrent[3];
948 Int_t idChamber = (atoi(cIdChamber) % kNdetsec);
949 cha = kNcham - ((Int_t) idChamber / kNplan) - 1;
950 pla = ((Int_t) idChamber % kNplan);
952 // Check on selected volumes
953 Int_t addthishit = 1;
959 // The detector number
960 det = fGeometry->GetDetector(pla,cha,sec);
962 // 0: InFlight 1:Entering 2:Exiting
965 // Special hits only in the drift region
968 // Create a track reference at the entrance and exit of each
969 // chamber that contain the momentum components of the particle
971 if (gMC->IsTrackEntering()) {
972 gMC->TrackMomentum(mom);
973 AddTrackReference(gAlice->GetMCApp()->GetCurrentTrackNumber());
976 if (gMC->IsTrackExiting()) {
977 gMC->TrackMomentum(mom);
978 AddTrackReference(gAlice->GetMCApp()->GetCurrentTrackNumber());
982 // Create the hits from TR photons
989 // Calculate the charge according to GEANT Edep
990 // Create a new dEdx hit
991 eDep = TMath::Max(gMC->Edep(),0.0) * 1.0e+09;
992 qTot = (Int_t) (eDep / kWion);
993 AddHit(gAlice->GetMCApp()->GetCurrentTrackNumber()
999 // Set Maximum Step Size
1000 // Produce only one hit if Ekin is below cutoff
1001 if ((gMC->Etot() - gMC->TrackMass()) < kEkinMinStep) {
1004 gMC->SetMaxStep(fStepSize);
1008 //_____________________________________________________________________________
1009 Double_t AliTRDv1::BetheBloch(Double_t bg)
1012 // Parametrization of the Bethe-Bloch-curve
1013 // The parametrization is the same as for the TPC and is taken from Lehrhaus.
1016 // This parameters have been adjusted to averaged values from GEANT
1017 const Double_t kP1 = 7.17960e-02;
1018 const Double_t kP2 = 8.54196;
1019 const Double_t kP3 = 1.38065e-06;
1020 const Double_t kP4 = 5.30972;
1021 const Double_t kP5 = 2.83798;
1023 // Lower cutoff of the Bethe-Bloch-curve to limit step sizes
1024 const Double_t kBgMin = 0.8;
1025 const Double_t kBBMax = 6.83298;
1028 Double_t yy = bg / TMath::Sqrt(1.0 + bg*bg);
1029 Double_t aa = TMath::Power(yy,kP4);
1030 Double_t bb = TMath::Power((1.0/bg),kP5);
1031 bb = TMath::Log(kP3 + bb);
1032 return ((kP2 - aa - bb) * kP1 / aa);
1040 //_____________________________________________________________________________
1041 Double_t AliTRDv1::BetheBlochGeant(Double_t bg)
1044 // Return dN/dx (number of primary collisions per centimeter)
1045 // for given beta*gamma factor.
1047 // Implemented by K.Oyama according to GEANT 3 parametrization shown in
1048 // A.Andronic's webpage: http://www-alice.gsi.de/trd/papers/dedx/dedx.html
1049 // This must be used as a set with IntSpecGeant.
1054 Double_t arrG[20] = { 1.100000, 1.200000, 1.300000, 1.500000
1055 , 1.800000, 2.000000, 2.500000, 3.000000
1056 , 4.000000, 7.000000, 10.000000, 20.000000
1057 , 40.000000, 70.000000, 100.000000, 300.000000
1058 , 600.000000, 1000.000000, 3000.000000, 10000.000000 };
1060 Double_t arrNC[20] = { 75.009056, 45.508083, 35.299252, 27.116327
1061 , 22.734999, 21.411915, 19.934095, 19.449375
1062 , 19.344431, 20.185553, 21.027925, 22.912676
1063 , 24.933352, 26.504053, 27.387468, 29.566597
1064 , 30.353779, 30.787134, 31.129285, 31.157350 };
1066 // Betagamma to gamma
1067 Double_t g = TMath::Sqrt(1.0 + bg*bg);
1069 // Find the index just before the point we need.
1070 for (i = 0; i < 18; i++) {
1071 if ((arrG[i] < g) &&
1077 // Simple interpolation.
1078 Double_t pp = ((arrNC[i+1] - arrNC[i]) / (arrG[i+1] - arrG[i]))
1079 * (g - arrG[i]) + arrNC[i];
1085 //_____________________________________________________________________________
1086 Double_t Ermilova(Double_t *x, Double_t *)
1089 // Calculates the delta-ray energy distribution according to Ermilova.
1090 // Logarithmic scale !
1100 const Int_t kNv = 31;
1102 Float_t vxe[kNv] = { 2.3026, 2.9957, 3.4012, 3.6889, 3.9120
1103 , 4.0943, 4.2485, 4.3820, 4.4998, 4.6052
1104 , 4.7005, 5.0752, 5.2983, 5.7038, 5.9915
1105 , 6.2146, 6.5221, 6.9078, 7.3132, 7.6009
1106 , 8.0064, 8.5172, 8.6995, 8.9872, 9.2103
1107 , 9.4727, 9.9035, 10.3735, 10.5966, 10.8198
1110 Float_t vye[kNv] = { 80.0, 31.0, 23.3, 21.1, 21.0
1111 , 20.9, 20.8, 20.0, 16.0, 11.0
1112 , 8.0, 6.0, 5.2, 4.6, 4.0
1113 , 3.5, 3.0, 1.4, 0.67, 0.44
1114 , 0.3, 0.18, 0.12, 0.08, 0.056
1115 , 0.04, 0.023, 0.015, 0.011, 0.01
1120 // Find the position
1125 dpos = energy - vxe[pos2++];
1134 // Differentiate between the sampling points
1135 dnde = (vye[pos1] - vye[pos2]) / (vxe[pos2] - vxe[pos1]);
1141 //_____________________________________________________________________________
1142 Double_t IntSpecGeant(Double_t *x, Double_t *)
1145 // Integrated spectrum from Geant3
1148 const Int_t npts = 83;
1149 Double_t arre[npts] = { 2.421257, 2.483278, 2.534301, 2.592230
1150 , 2.672067, 2.813299, 3.015059, 3.216819
1151 , 3.418579, 3.620338, 3.868209, 3.920198
1152 , 3.978284, 4.063923, 4.186264, 4.308605
1153 , 4.430946, 4.553288, 4.724261, 4.837736
1154 , 4.999842, 5.161949, 5.324056, 5.486163
1155 , 5.679688, 5.752998, 5.857728, 5.962457
1156 , 6.067185, 6.171914, 6.315653, 6.393674
1157 , 6.471694, 6.539689, 6.597658, 6.655627
1158 , 6.710957, 6.763648, 6.816338, 6.876198
1159 , 6.943227, 7.010257, 7.106285, 7.252151
1160 , 7.460531, 7.668911, 7.877290, 8.085670
1161 , 8.302979, 8.353585, 8.413120, 8.483500
1162 , 8.541030, 8.592857, 8.668865, 8.820485
1163 , 9.037086, 9.253686, 9.470286, 9.686887
1164 , 9.930838, 9.994655, 10.085822, 10.176990
1165 , 10.268158, 10.359325, 10.503614, 10.627565
1166 , 10.804637, 10.981709, 11.158781, 11.335854
1167 , 11.593397, 11.781165, 12.049404, 12.317644
1168 , 12.585884, 12.854123, 14.278421, 16.975889
1169 , 20.829416, 24.682943, 28.536469 };
1171 Double_t arrdnde[npts] = { 10.960000, 10.960000, 10.359500, 9.811340
1172 , 9.1601500, 8.206670, 6.919630, 5.655430
1173 , 4.6221300, 3.777610, 3.019560, 2.591950
1174 , 2.5414600, 2.712920, 3.327460, 4.928240
1175 , 7.6185300, 10.966700, 12.225800, 8.094750
1176 , 3.3586900, 1.553650, 1.209600, 1.263840
1177 , 1.3241100, 1.312140, 1.255130, 1.165770
1178 , 1.0594500, 0.945450, 0.813231, 0.699837
1179 , 0.6235580, 2.260990, 2.968350, 2.240320
1180 , 1.7988300, 1.553300, 1.432070, 1.535520
1181 , 1.4429900, 1.247990, 1.050750, 0.829549
1182 , 0.5900280, 0.395897, 0.268741, 0.185320
1183 , 0.1292120, 0.103545, 0.0949525, 0.101535
1184 , 0.1276380, 0.134216, 0.123816, 0.104557
1185 , 0.0751843, 0.0521745, 0.0373546, 0.0275391
1186 , 0.0204713, 0.0169234, 0.0154552, 0.0139194
1187 , 0.0125592, 0.0113638, 0.0107354, 0.0102137
1188 , 0.00845984, 0.00683338, 0.00556836, 0.00456874
1189 , 0.0036227, 0.00285991, 0.00226664, 0.00172234
1190 , 0.00131226, 0.00100284, 0.000465492, 7.26607e-05
1191 , 3.63304e-06, 0.0000000, 0.0000000 };
1194 Double_t energy = x[0];
1196 for (i = 0; i < npts; i++) {
1197 if (energy < arre[i]) {
1203 AliErrorGeneral("AliTRDv1::IntSpecGeant","Given energy value is too small or zero");