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 Float_t kWion = 23.53;
231 // Maximum number of TR photons per track
232 const Int_t kNTR = 50;
241 gMC->TrackMomentum(mom);
242 Float_t pTot = mom.Rho();
243 fTR->CreatePhotons(11,pTot,nTR,eTR);
245 AliFatal(Form("Boundary error: nTR = %d, kNTR = %d",nTR,kNTR));
248 // Loop through the TR photons
249 for (Int_t iTR = 0; iTR < nTR; iTR++) {
251 Float_t energyMeV = eTR[iTR] * 0.001;
252 Float_t energyeV = eTR[iTR] * 1000.0;
253 Float_t absLength = 0.0;
256 // Take the absorbtion in the entrance window into account
257 Double_t muMy = fTR->GetMuMy(energyMeV);
258 sigma = muMy * fFoilDensity;
260 absLength = gRandom->Exp(1.0/sigma);
261 if (absLength < AliTRDgeometry::MyThick()) {
269 // The absorbtion cross sections in the drift gas
270 // Gas-mixture (Xe/CO2)
271 Double_t muXe = fTR->GetMuXe(energyMeV);
272 Double_t muCO = fTR->GetMuCO(energyMeV);
273 sigma = (0.85 * muXe + 0.15 * muCO) * fGasDensity * fTR->GetTemp();
275 // The distance after which the energy of the TR photon
278 absLength = gRandom->Exp(1.0/sigma);
279 if (absLength > (AliTRDgeometry::DrThick()
280 + AliTRDgeometry::AmThick())) {
288 // The position of the absorbtion
290 gMC->TrackPosition(pos);
291 posHit[0] = pos[0] + mom[0] / pTot * absLength;
292 posHit[1] = pos[1] + mom[1] / pTot * absLength;
293 posHit[2] = pos[2] + mom[2] / pTot * absLength;
296 Int_t q = ((Int_t) (energyeV / kWion));
298 // Add the hit to the array. TR photon hits are marked
299 // by negative charge
300 // The hit time is needed for pile-up events
301 AddHit(gAlice->GetMCApp()->GetCurrentTrackNumber()
305 ,gMC->TrackTime()*1.0e06
312 //_____________________________________________________________________________
313 void AliTRDv1::Init()
316 // Initialise Transition Radiation Detector after geometry has been built.
321 AliDebug(1,"Slow simulator\n");
323 // Switch on TR simulation as default
325 AliInfo("TR simulation off");
328 fTR = new AliTRDsim();
331 // First ionization potential (eV) for the gas mixture (90% Xe + 10% CO2)
332 const Float_t kPoti = 12.1;
333 // Maximum energy (50 keV);
334 const Float_t kEend = 50000.0;
335 // Ermilova distribution for the delta-ray spectrum
336 Float_t poti = TMath::Log(kPoti);
337 Float_t eEnd = TMath::Log(kEend);
339 // Ermilova distribution for the delta-ray spectrum
340 fDeltaE = new TF1("deltae" ,Ermilova ,poti,eEnd,0);
342 // Geant3 distribution for the delta-ray spectrum
343 fDeltaG = new TF1("deltag",IntSpecGeant,2.421257,28.536469,0);
345 AliDebug(1,"+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++");
349 //_____________________________________________________________________________
350 void AliTRDv1::StepManager()
353 // Slow simulator. Every charged track produces electron cluster as hits
354 // along its path across the drift volume.
357 switch (fTypeOfStepManager) {
359 StepManagerErmilova();
365 StepManagerFixedStep();
368 AliWarning("Not a valid Step Manager.");
373 //_____________________________________________________________________________
374 void AliTRDv1::SelectStepManager(Int_t t)
377 // Selects a step manager type:
380 // 2 - Fixed step size
383 fTypeOfStepManager = t;
384 AliInfo(Form("Step Manager type %d was selected",fTypeOfStepManager));
388 //_____________________________________________________________________________
389 void AliTRDv1::StepManagerGeant()
392 // Slow simulator. Every charged track produces electron cluster as hits
393 // along its path across the drift volume. The step size is set acording
394 // to Bethe-Bloch. The energy distribution of the delta electrons follows
395 // a spectrum taken from Geant3.
397 // Version by A. Bercuci
415 Double_t stepSize = 0;
417 Bool_t drRegion = kFALSE;
418 Bool_t amRegion = kFALSE;
425 TString cIdSensDr = "J";
426 TString cIdSensAm = "K";
427 Char_t cIdChamber[3];
435 const Int_t kNplan = AliTRDgeometry::Nplan();
436 const Int_t kNcham = AliTRDgeometry::Ncham();
437 const Int_t kNdetsec = kNplan * kNcham;
439 const Double_t kBig = 1.0e+12; // Infinitely big
440 const Float_t kWion = 23.53; // Ionization energy
441 const Float_t kPTotMaxEl = 0.002; // Maximum momentum for e+ e- g
443 // Minimum energy for the step size adjustment
444 const Float_t kEkinMinStep = 1.0e-5;
445 // energy threshold for production of delta electrons
446 const Float_t kECut = 1.0e4;
447 // Parameters entering the parametrized range for delta electrons
448 const Float_t kRa = 5.37e-4;
449 const Float_t kRb = 0.9815;
450 const Float_t kRc = 3.123e-3;
451 // Gas density -> To be made user adjustable !
452 // [0.85*0.00549+0.15*0.00186 (Xe-CO2 85-15)]
453 const Float_t kRho = 0.004945 ;
455 // Plateau value of the energy-loss for electron in xenon
456 // The averaged value (26/3/99)
457 const Float_t kPlateau = 1.55;
458 // dN1/dx|min for the gas mixture (90% Xe + 10% CO2)
459 const Float_t kPrim = 19.34;
460 // First ionization potential (eV) for the gas mixture (90% Xe + 10% CO2)
461 const Float_t kPoti = 12.1;
463 const Int_t kPdgElectron = 11;
465 // Set the maximum step size to a very large number for all
466 // neutral particles and those outside the driftvolume
467 gMC->SetMaxStep(kBig);
469 // Use only charged tracks
470 if (( gMC->TrackCharge() ) &&
471 (!gMC->IsTrackDisappeared())) {
473 // Inside a sensitive volume?
476 cIdCurrent = gMC->CurrentVolName();
477 if (cIdSensDr == cIdCurrent[1]) {
480 if (cIdSensAm == cIdCurrent[1]) {
483 if (drRegion || amRegion) {
485 // The hit coordinates and charge
486 gMC->TrackPosition(pos);
491 // The sector number (0 - 17), according to standard coordinate system
492 cIdPath = gGeoManager->GetPath();
493 cIdSector[0] = cIdPath[21];
494 cIdSector[1] = cIdPath[22];
495 sec = atoi(cIdSector);
497 // The plane and chamber number
498 cIdChamber[0] = cIdCurrent[2];
499 cIdChamber[1] = cIdCurrent[3];
500 Int_t idChamber = (atoi(cIdChamber) % kNdetsec);
501 cha = ((Int_t) idChamber / kNplan);
502 pla = ((Int_t) idChamber % kNplan);
504 // The detector number
505 det = fGeometry->GetDetector(pla,cha,sec);
507 // Special hits only in the drift region
509 (gMC->IsTrackEntering())) {
511 // Create a track reference at the entrance of each
512 // chamber that contains the momentum components of the particle
513 gMC->TrackMomentum(mom);
514 AddTrackReference(gAlice->GetMCApp()->GetCurrentTrackNumber());
516 // Create the hits from TR photons if electron/positron is
517 // entering the drift volume
519 (TMath::Abs(gMC->TrackPid()) == kPdgElectron)) {
524 else if ((amRegion) &&
525 (gMC->IsTrackExiting())) {
527 // Create a track reference at the exit of each
528 // chamber that contains the momentum components of the particle
529 gMC->TrackMomentum(mom);
530 AddTrackReference(gAlice->GetMCApp()->GetCurrentTrackNumber());
534 // Calculate the energy of the delta-electrons
535 // modified by Alex Bercuci (A.Bercuci@gsi.de) on 26.01.06
536 // take into account correlation with the underlying GEANT tracking
538 // http://www-linux.gsi.de/~abercuci/Contributions/TRD/index.html
540 // determine the most significant process (last on the processes list)
541 // which caused this hit
542 gMC->StepProcesses(processes);
543 Int_t nofprocesses = processes.GetSize();
549 pid = processes[nofprocesses-1];
552 // Generate Edep according to GEANT parametrisation
553 eDelta = TMath::Exp(fDeltaG->GetRandom()) - kPoti;
554 eDelta = TMath::Max(eDelta,0.0);
555 Float_t prRange = 0.0;
556 Float_t range = gMC->TrackLength() - fTrackLength0;
557 // merge GEANT tracker information with locally cooked one
558 if (gAlice->GetMCApp()->GetCurrentTrackNumber() == fPrimaryTrackPid) {
560 if (eDelta >= kECut) {
561 prRange = kRa * eDelta * 0.001
562 * (1.0 - kRb / (1.0 + kRc * eDelta * 0.001)) / kRho;
563 if (prRange >= (3.7 - range)) {
569 if (eDelta < kECut) {
573 prRange = kRa * eDelta * 0.001
574 * (1.0 - kRb / (1.0 + kRc * eDelta * 0.001)) / kRho;
575 if (prRange >= ((AliTRDgeometry::DrThick()
576 + AliTRDgeometry::AmThick()) - range)) {
592 // Generate the electron cluster size
595 qTot = ((Int_t) (eDelta / kWion) + 1);
597 // Create a new dEdx hit
598 // The hit time is needed for pile-up events
599 AddHit(gAlice->GetMCApp()->GetCurrentTrackNumber()
603 ,gMC->TrackTime()*1.0e06
608 // Calculate the maximum step size for the next tracking step
609 // Produce only one hit if Ekin is below cutoff
610 aMass = gMC->TrackMass();
611 if ((gMC->Etot() - aMass) > kEkinMinStep) {
613 // The energy loss according to Bethe Bloch
614 iPdg = TMath::Abs(gMC->TrackPid());
615 if ((iPdg != kPdgElectron) ||
616 ((iPdg == kPdgElectron) &&
617 (pTot < kPTotMaxEl))) {
618 gMC->TrackMomentum(mom);
620 betaGamma = pTot / aMass;
621 pp = BetheBlochGeant(betaGamma);
622 // Take charge > 1 into account
623 charge = gMC->TrackCharge();
624 if (TMath::Abs(charge) > 1) {
625 pp = pp * charge*charge;
629 // Electrons above 20 Mev/c are at the plateau
630 pp = kPrim * kPlateau;
635 nsteps = gRandom->Poisson(pp);
637 stepSize = 1.0 / nsteps;
638 gMC->SetMaxStep(stepSize);
648 //_____________________________________________________________________________
649 void AliTRDv1::StepManagerErmilova()
652 // Slow simulator. Every charged track produces electron cluster as hits
653 // along its path across the drift volume. The step size is set acording
654 // to Bethe-Bloch. The energy distribution of the delta electrons follows
655 // a spectrum taken from Ermilova et al.
676 Bool_t drRegion = kFALSE;
677 Bool_t amRegion = kFALSE;
684 TString cIdSensDr = "J";
685 TString cIdSensAm = "K";
686 Char_t cIdChamber[3];
692 const Int_t kNplan = AliTRDgeometry::Nplan();
693 const Int_t kNcham = AliTRDgeometry::Ncham();
694 const Int_t kNdetsec = kNplan * kNcham;
696 const Double_t kBig = 1.0e+12; // Infinitely big
697 const Float_t kWion = 23.53; // Ionization energy
698 const Float_t kPTotMaxEl = 0.002; // Maximum momentum for e+ e- g
700 // Minimum energy for the step size adjustment
701 const Float_t kEkinMinStep = 1.0e-5;
703 // Plateau value of the energy-loss for electron in xenon
704 // The averaged value (26/3/99)
705 const Float_t kPlateau = 1.55;
706 // dN1/dx|min for the gas mixture (90% Xe + 10% CO2)
707 const Float_t kPrim = 48.0;
708 // First ionization potential (eV) for the gas mixture (90% Xe + 10% CO2)
709 const Float_t kPoti = 12.1;
711 const Int_t kPdgElectron = 11;
713 // Set the maximum step size to a very large number for all
714 // neutral particles and those outside the driftvolume
715 gMC->SetMaxStep(kBig);
717 // Use only charged tracks
718 if (( gMC->TrackCharge() ) &&
719 (!gMC->IsTrackDisappeared())) {
721 // Inside a sensitive volume?
724 cIdCurrent = gMC->CurrentVolName();
725 if (cIdSensDr == cIdCurrent[1]) {
728 if (cIdSensAm == cIdCurrent[1]) {
731 if (drRegion || amRegion) {
733 // The hit coordinates and charge
734 gMC->TrackPosition(pos);
739 // The sector number (0 - 17), according to standard coordinate system
740 cIdPath = gGeoManager->GetPath();
741 cIdSector[0] = cIdPath[21];
742 cIdSector[1] = cIdPath[22];
743 sec = atoi(cIdSector);
745 // The plane and chamber number
746 cIdChamber[0] = cIdCurrent[2];
747 cIdChamber[1] = cIdCurrent[3];
748 Int_t idChamber = (atoi(cIdChamber) % kNdetsec);
749 cha = ((Int_t) idChamber / kNplan);
750 pla = ((Int_t) idChamber % kNplan);
752 // The detector number
753 det = fGeometry->GetDetector(pla,cha,sec);
755 // Special hits only in the drift region
757 (gMC->IsTrackEntering())) {
759 // Create a track reference at the entrance of each
760 // chamber that contains the momentum components of the particle
761 gMC->TrackMomentum(mom);
762 AddTrackReference(gAlice->GetMCApp()->GetCurrentTrackNumber());
764 // Create the hits from TR photons if electron/positron is
765 // entering the drift volume
767 (TMath::Abs(gMC->TrackPid()) == kPdgElectron)) {
772 else if ((amRegion) &&
773 (gMC->IsTrackExiting())) {
775 // Create a track reference at the exit of each
776 // chamber that contains the momentum components of the particle
777 gMC->TrackMomentum(mom);
778 AddTrackReference(gAlice->GetMCApp()->GetCurrentTrackNumber());
782 // Calculate the energy of the delta-electrons
783 eDelta = TMath::Exp(fDeltaE->GetRandom()) - kPoti;
784 eDelta = TMath::Max(eDelta,0.0);
786 // Generate the electron cluster size
789 qTot = ((Int_t) (eDelta / kWion) + 1);
791 // Create a new dEdx hit
792 // The hit time is needed for pile-up events
794 AddHit(gAlice->GetMCApp()->GetCurrentTrackNumber()
798 ,gMC->TrackTime()*1.0e06
802 AddHit(gAlice->GetMCApp()->GetCurrentTrackNumber()
806 ,gMC->TrackTime()*1.0e06
812 // Calculate the maximum step size for the next tracking step
813 // Produce only one hit if Ekin is below cutoff
814 aMass = gMC->TrackMass();
815 if ((gMC->Etot() - aMass) > kEkinMinStep) {
817 // The energy loss according to Bethe Bloch
818 iPdg = TMath::Abs(gMC->TrackPid());
819 if ((iPdg != kPdgElectron) ||
820 ((iPdg == kPdgElectron) &&
821 (pTot < kPTotMaxEl))) {
822 gMC->TrackMomentum(mom);
824 betaGamma = pTot / aMass;
825 pp = kPrim * BetheBloch(betaGamma);
826 // Take charge > 1 into account
827 charge = gMC->TrackCharge();
828 if (TMath::Abs(charge) > 1) {
829 pp = pp * charge*charge;
833 // Electrons above 20 Mev/c are at the plateau
834 pp = kPrim * kPlateau;
839 gMC->GetRandom()->RndmArray(1,random);
841 while ((random[0] == 1.0) ||
843 stepSize = - TMath::Log(random[0]) / pp;
844 gMC->SetMaxStep(stepSize);
855 //_____________________________________________________________________________
856 void AliTRDv1::StepManagerFixedStep()
859 // Slow simulator. Every charged track produces electron cluster as hits
860 // along its path across the drift volume. The step size is fixed in
861 // this version of the step manager.
865 const Int_t kPdgElectron = 11;
876 Bool_t drRegion = kFALSE;
877 Bool_t amRegion = kFALSE;
884 TString cIdSensDr = "J";
885 TString cIdSensAm = "K";
886 Char_t cIdChamber[3];
892 const Int_t kNplan = AliTRDgeometry::Nplan();
893 const Int_t kNcham = AliTRDgeometry::Ncham();
894 const Int_t kNdetsec = kNplan * kNcham;
896 const Double_t kBig = 1.0e+12;
898 const Float_t kWion = 23.53; // Ionization energy
899 const Float_t kEkinMinStep = 1.0e-5; // Minimum energy for the step size adjustment
901 // Set the maximum step size to a very large number for all
902 // neutral particles and those outside the driftvolume
903 gMC->SetMaxStep(kBig);
905 // If not charged track or already stopped or disappeared, just return.
906 if ((!gMC->TrackCharge()) ||
907 gMC->IsTrackDisappeared()) {
911 // Inside a sensitive volume?
912 cIdCurrent = gMC->CurrentVolName();
914 if (cIdSensDr == cIdCurrent[1]) {
917 if (cIdSensAm == cIdCurrent[1]) {
926 // The hit coordinates and charge
927 gMC->TrackPosition(pos);
932 // The sector number (0 - 17), according to standard coordinate system
933 cIdPath = gGeoManager->GetPath();
934 cIdSector[0] = cIdPath[21];
935 cIdSector[1] = cIdPath[22];
936 sec = atoi(cIdSector);
938 // The plane and chamber number
939 cIdChamber[0] = cIdCurrent[2];
940 cIdChamber[1] = cIdCurrent[3];
941 Int_t idChamber = (atoi(cIdChamber) % kNdetsec);
942 cha = ((Int_t) idChamber / kNplan);
943 pla = ((Int_t) idChamber % kNplan);
945 // The detector number
946 det = fGeometry->GetDetector(pla,cha,sec);
948 // 0:InFlight 1:Entering 2:Exiting
951 // Special hits only in the drift region
953 (gMC->IsTrackEntering())) {
955 // Create a track reference at the entrance of each
956 // chamber that contains the momentum components of the particle
957 gMC->TrackMomentum(mom);
958 AddTrackReference(gAlice->GetMCApp()->GetCurrentTrackNumber());
961 // Create the hits from TR photons if electron/positron is
962 // entering the drift volume
964 (TMath::Abs(gMC->TrackPid()) == kPdgElectron)) {
969 else if ((amRegion) &&
970 (gMC->IsTrackExiting())) {
972 // Create a track reference at the exit of each
973 // chamber that contains the momentum components of the particle
974 gMC->TrackMomentum(mom);
975 AddTrackReference(gAlice->GetMCApp()->GetCurrentTrackNumber());
980 // Calculate the charge according to GEANT Edep
981 // Create a new dEdx hit
982 // The hit time is needed for pile-up events
983 eDep = TMath::Max(gMC->Edep(),0.0) * 1.0e+09;
984 qTot = (Int_t) (eDep / kWion);
987 AddHit(gAlice->GetMCApp()->GetCurrentTrackNumber()
991 ,gMC->TrackTime()*1.0e06
995 // Set Maximum Step Size
996 // Produce only one hit if Ekin is below cutoff
997 if ((gMC->Etot() - gMC->TrackMass()) < kEkinMinStep) {
1000 gMC->SetMaxStep(fStepSize);
1004 //_____________________________________________________________________________
1005 Double_t AliTRDv1::BetheBloch(Double_t bg)
1008 // Parametrization of the Bethe-Bloch-curve
1009 // The parametrization is the same as for the TPC and is taken from Lehrhaus.
1012 // This parameters have been adjusted to averaged values from GEANT
1013 const Double_t kP1 = 7.17960e-02;
1014 const Double_t kP2 = 8.54196;
1015 const Double_t kP3 = 1.38065e-06;
1016 const Double_t kP4 = 5.30972;
1017 const Double_t kP5 = 2.83798;
1019 // Lower cutoff of the Bethe-Bloch-curve to limit step sizes
1020 const Double_t kBgMin = 0.8;
1021 const Double_t kBBMax = 6.83298;
1024 Double_t yy = bg / TMath::Sqrt(1.0 + bg*bg);
1025 Double_t aa = TMath::Power(yy,kP4);
1026 Double_t bb = TMath::Power((1.0/bg),kP5);
1027 bb = TMath::Log(kP3 + bb);
1028 return ((kP2 - aa - bb) * kP1 / aa);
1036 //_____________________________________________________________________________
1037 Double_t AliTRDv1::BetheBlochGeant(Double_t bg)
1040 // Return dN/dx (number of primary collisions per centimeter)
1041 // for given beta*gamma factor.
1043 // Implemented by K.Oyama according to GEANT 3 parametrization shown in
1044 // A.Andronic's webpage: http://www-alice.gsi.de/trd/papers/dedx/dedx.html
1045 // This must be used as a set with IntSpecGeant.
1050 Double_t arrG[20] = { 1.100000, 1.200000, 1.300000, 1.500000
1051 , 1.800000, 2.000000, 2.500000, 3.000000
1052 , 4.000000, 7.000000, 10.000000, 20.000000
1053 , 40.000000, 70.000000, 100.000000, 300.000000
1054 , 600.000000, 1000.000000, 3000.000000, 10000.000000 };
1056 Double_t arrNC[20] = { 75.009056, 45.508083, 35.299252, 27.116327
1057 , 22.734999, 21.411915, 19.934095, 19.449375
1058 , 19.344431, 20.185553, 21.027925, 22.912676
1059 , 24.933352, 26.504053, 27.387468, 29.566597
1060 , 30.353779, 30.787134, 31.129285, 31.157350 };
1062 // Betagamma to gamma
1063 Double_t g = TMath::Sqrt(1.0 + bg*bg);
1065 // Find the index just before the point we need.
1066 for (i = 0; i < 18; i++) {
1067 if ((arrG[i] < g) &&
1073 // Simple interpolation.
1074 Double_t pp = ((arrNC[i+1] - arrNC[i]) / (arrG[i+1] - arrG[i]))
1075 * (g - arrG[i]) + arrNC[i];
1081 //_____________________________________________________________________________
1082 Double_t Ermilova(Double_t *x, Double_t *)
1085 // Calculates the delta-ray energy distribution according to Ermilova.
1086 // Logarithmic scale !
1096 const Int_t kNv = 31;
1098 Float_t vxe[kNv] = { 2.3026, 2.9957, 3.4012, 3.6889, 3.9120
1099 , 4.0943, 4.2485, 4.3820, 4.4998, 4.6052
1100 , 4.7005, 5.0752, 5.2983, 5.7038, 5.9915
1101 , 6.2146, 6.5221, 6.9078, 7.3132, 7.6009
1102 , 8.0064, 8.5172, 8.6995, 8.9872, 9.2103
1103 , 9.4727, 9.9035, 10.3735, 10.5966, 10.8198
1106 Float_t vye[kNv] = { 80.0, 31.0, 23.3, 21.1, 21.0
1107 , 20.9, 20.8, 20.0, 16.0, 11.0
1108 , 8.0, 6.0, 5.2, 4.6, 4.0
1109 , 3.5, 3.0, 1.4, 0.67, 0.44
1110 , 0.3, 0.18, 0.12, 0.08, 0.056
1111 , 0.04, 0.023, 0.015, 0.011, 0.01
1116 // Find the position
1121 dpos = energy - vxe[pos2++];
1130 // Differentiate between the sampling points
1131 dnde = (vye[pos1] - vye[pos2]) / (vxe[pos2] - vxe[pos1]);
1137 //_____________________________________________________________________________
1138 Double_t IntSpecGeant(Double_t *x, Double_t *)
1141 // Integrated spectrum from Geant3
1144 const Int_t npts = 83;
1145 Double_t arre[npts] = { 2.421257, 2.483278, 2.534301, 2.592230
1146 , 2.672067, 2.813299, 3.015059, 3.216819
1147 , 3.418579, 3.620338, 3.868209, 3.920198
1148 , 3.978284, 4.063923, 4.186264, 4.308605
1149 , 4.430946, 4.553288, 4.724261, 4.837736
1150 , 4.999842, 5.161949, 5.324056, 5.486163
1151 , 5.679688, 5.752998, 5.857728, 5.962457
1152 , 6.067185, 6.171914, 6.315653, 6.393674
1153 , 6.471694, 6.539689, 6.597658, 6.655627
1154 , 6.710957, 6.763648, 6.816338, 6.876198
1155 , 6.943227, 7.010257, 7.106285, 7.252151
1156 , 7.460531, 7.668911, 7.877290, 8.085670
1157 , 8.302979, 8.353585, 8.413120, 8.483500
1158 , 8.541030, 8.592857, 8.668865, 8.820485
1159 , 9.037086, 9.253686, 9.470286, 9.686887
1160 , 9.930838, 9.994655, 10.085822, 10.176990
1161 , 10.268158, 10.359325, 10.503614, 10.627565
1162 , 10.804637, 10.981709, 11.158781, 11.335854
1163 , 11.593397, 11.781165, 12.049404, 12.317644
1164 , 12.585884, 12.854123, 14.278421, 16.975889
1165 , 20.829416, 24.682943, 28.536469 };
1167 Double_t arrdnde[npts] = { 10.960000, 10.960000, 10.359500, 9.811340
1168 , 9.1601500, 8.206670, 6.919630, 5.655430
1169 , 4.6221300, 3.777610, 3.019560, 2.591950
1170 , 2.5414600, 2.712920, 3.327460, 4.928240
1171 , 7.6185300, 10.966700, 12.225800, 8.094750
1172 , 3.3586900, 1.553650, 1.209600, 1.263840
1173 , 1.3241100, 1.312140, 1.255130, 1.165770
1174 , 1.0594500, 0.945450, 0.813231, 0.699837
1175 , 0.6235580, 2.260990, 2.968350, 2.240320
1176 , 1.7988300, 1.553300, 1.432070, 1.535520
1177 , 1.4429900, 1.247990, 1.050750, 0.829549
1178 , 0.5900280, 0.395897, 0.268741, 0.185320
1179 , 0.1292120, 0.103545, 0.0949525, 0.101535
1180 , 0.1276380, 0.134216, 0.123816, 0.104557
1181 , 0.0751843, 0.0521745, 0.0373546, 0.0275391
1182 , 0.0204713, 0.0169234, 0.0154552, 0.0139194
1183 , 0.0125592, 0.0113638, 0.0107354, 0.0102137
1184 , 0.00845984, 0.00683338, 0.00556836, 0.00456874
1185 , 0.0036227, 0.00285991, 0.00226664, 0.00172234
1186 , 0.00131226, 0.00100284, 0.000465492, 7.26607e-05
1187 , 3.63304e-06, 0.0000000, 0.0000000 };
1190 Double_t energy = x[0];
1192 for (i = 0; i < npts; i++) {
1193 if (energy < arre[i]) {
1199 AliErrorGeneral("AliTRDv1::IntSpecGeant","Given energy value is too small or zero");