* provided "as is" without express or implied warranty. *
**************************************************************************/
-/*
-$Log$
-*/
-
-///////////////////////////////////////////////////////////////////////////////
-// //
-// Transition Radiation Detector version 1 -- coarse simulation //
-// This version has two detector arms, leaving the space in front of the //
-// HMPID and PHOS empty //
-// //
-//Begin_Html
-/*
-<img src="picts/AliTRDv1Class.gif">
-*/
-//End_Html
-// //
-// //
-///////////////////////////////////////////////////////////////////////////////
+/* $Id$ */
+////////////////////////////////////////////////////////////////////////////
+// //
+// Transition Radiation Detector version 1 -- slow simulator //
+// //
+////////////////////////////////////////////////////////////////////////////
+
+#include <TLorentzVector.h>
#include <TMath.h>
#include <TRandom.h>
-#include <TVector.h>
+#include <TVirtualMC.h>
+#include <TGeoManager.h>
+#include <TGeoMatrix.h>
+#include <TGeoPhysicalNode.h>
-#include "AliTRDv1.h"
-#include "AliRun.h"
+#include "AliTrackReference.h"
#include "AliMC.h"
-#include "AliConst.h"
-
+#include "AliRun.h"
+#include "AliGeomManager.h"
+
+#include "AliTRDgeometry.h"
+#include "AliTRDCommonParam.h"
+#include "AliTRDsimTR.h"
+#include "AliTRDv1.h"
+
ClassImp(AliTRDv1)
+
+//_____________________________________________________________________________
+AliTRDv1::AliTRDv1()
+ :AliTRD()
+ ,fTRon(kTRUE)
+ ,fTR(NULL)
+ ,fStepSize(0)
+ ,fWion(0)
+{
+ //
+ // Default constructor
+ //
+
+}
//_____________________________________________________________________________
AliTRDv1::AliTRDv1(const char *name, const char *title)
- :AliTRD(name, title)
+ :AliTRD(name,title)
+ ,fTRon(kTRUE)
+ ,fTR(NULL)
+ ,fStepSize(0.1)
+ ,fWion(0)
{
//
- // Standard constructor for the Transition Radiation Detector version 1
+ // Standard constructor for Transition Radiation Detector version 1
//
- fIdSens = 0;
- fHitsOn = 0;
+ SetBufferSize(128000);
+
+ if (AliTRDCommonParam::Instance()->IsXenon()) {
+ fWion = 23.53; // Ionization energy XeCO2 (85/15)
+ }
+ else if (AliTRDCommonParam::Instance()->IsArgon()) {
+ fWion = 27.21; // Ionization energy ArCO2 (82/18)
+ }
+ else {
+ AliFatal("Wrong gas mixture");
+ exit(1);
+ }
+
+}
- fIdSpace1 = 0;
- fIdSpace2 = 0;
- fIdSpace3 = 0;
+//_____________________________________________________________________________
+AliTRDv1::~AliTRDv1()
+{
+ //
+ // AliTRDv1 destructor
+ //
- fIdChamber1 = 0;
- fIdChamber2 = 0;
- fIdChamber3 = 0;
+ if (fTR) {
+ delete fTR;
+ fTR = 0;
+ }
}
//_____________________________________________________________________________
-void AliTRDv1::CreateGeometry()
+void AliTRDv1::AddAlignableVolumes() const
{
//
- // Create the GEANT geometry for the Transition Radiation Detector - Version 1
- // This version covers only part of the azimuth.
+ // Create entries for alignable volumes associating the symbolic volume
+ // name with the corresponding volume path. Needs to be syncronized with
+ // eventual changes in the geometry.
+ //
+
+ TString volPath;
+ TString symName;
+
+ TString vpStr = "ALIC_1/B077_1/BSEGMO";
+ TString vpApp1 = "_1/BTRD";
+ TString vpApp2 = "_1";
+ TString vpApp3a = "/UTR1_1/UTS1_1/UTI1_1/UT";
+ TString vpApp3b = "/UTR2_1/UTS2_1/UTI2_1/UT";
+ TString vpApp3c = "/UTR3_1/UTS3_1/UTI3_1/UT";
+
+ TString snStr = "TRD/sm";
+ TString snApp1 = "/st";
+ TString snApp2 = "/pl";
+
+ //
+ // The super modules
+ // The symbolic names are: TRD/sm00
+ // ...
+ // TRD/sm17
+ //
+ for (Int_t isector = 0; isector < AliTRDgeometry::Nsector(); isector++) {
+
+ volPath = vpStr;
+ volPath += isector;
+ volPath += vpApp1;
+ volPath += isector;
+ volPath += vpApp2;
+
+ symName = snStr;
+ symName += Form("%02d",isector);
+
+ gGeoManager->SetAlignableEntry(symName.Data(),volPath.Data());
+
+ }
+
//
- // Author: Christoph Blume (C.Blume@gsi.de) 20/07/99
+ // The readout chambers
+ // The symbolic names are: TRD/sm00/st0/pl0
+ // ...
+ // TRD/sm17/st4/pl5
//
+ AliGeomManager::ELayerID idTRD1 = AliGeomManager::kTRD1;
+ Int_t layer, modUID;
+
+ for (Int_t isector = 0; isector < AliTRDgeometry::Nsector(); isector++) {
+
+ if (fGeometry->GetSMstatus(isector) == 0) continue;
+
+ for (Int_t istack = 0; istack < AliTRDgeometry::Nstack(); istack++) {
+ for (Int_t ilayer = 0; ilayer < AliTRDgeometry::Nlayer(); ilayer++) {
+
+ layer = idTRD1 + ilayer;
+ modUID = AliGeomManager::LayerToVolUIDSafe(layer,isector*5+istack);
+
+ Int_t idet = AliTRDgeometry::GetDetectorSec(ilayer,istack);
+
+ volPath = vpStr;
+ volPath += isector;
+ volPath += vpApp1;
+ volPath += isector;
+ volPath += vpApp2;
+ switch (isector) {
+ case 13:
+ case 14:
+ case 15:
+ if (istack == 2) {
+ continue;
+ }
+ volPath += vpApp3c;
+ break;
+ case 11:
+ case 12:
+ volPath += vpApp3b;
+ break;
+ default:
+ volPath += vpApp3a;
+ };
+ volPath += Form("%02d",idet);
+ volPath += vpApp2;
+
+ symName = snStr;
+ symName += Form("%02d",isector);
+ symName += snApp1;
+ symName += istack;
+ symName += snApp2;
+ symName += ilayer;
+
+ TGeoPNEntry *alignableEntry =
+ gGeoManager->SetAlignableEntry(symName.Data(),volPath.Data(),modUID);
+
+ // Add the tracking to local matrix following the TPC example
+ if (alignableEntry) {
+ TGeoHMatrix *globMatrix = alignableEntry->GetGlobalOrig();
+ Double_t sectorAngle = 20.0 * (isector % 18) + 10.0;
+ TGeoHMatrix *t2lMatrix = new TGeoHMatrix();
+ t2lMatrix->RotateZ(sectorAngle);
+ t2lMatrix->MultiplyLeft(&(globMatrix->Inverse()));
+ alignableEntry->SetMatrix(t2lMatrix);
+ }
+ else {
+ AliError(Form("Alignable entry %s is not valid!",symName.Data()));
+ }
+
+ }
+ }
+ }
- Float_t xpos, ypos, zpos;
+}
+
+//_____________________________________________________________________________
+void AliTRDv1::CreateGeometry()
+{
+ //
+ // Create the GEANT geometry for the Transition Radiation Detector - Version 1
+ // This version covers the full azimuth.
+ //
// Check that FRAME is there otherwise we have no place where to put the TRD
- AliModule* FRAME = gAlice->GetModule("FRAME");
- if (!FRAME) return;
+ AliModule* frame = gAlice->GetModule("FRAME");
+ if (!frame) {
+ AliError("TRD needs FRAME to be present\n");
+ return;
+ }
// Define the chambers
AliTRD::CreateGeometry();
- // Position the the TRD-sectors only in one TRD-volume in the spaceframe
- xpos = 0.;
- ypos = 0.;
- zpos = 0.;
- gMC->Gspos("TRD ",1,"BTR1",xpos,ypos,zpos,0,"ONLY");
-
}
//_____________________________________________________________________________
}
+//_____________________________________________________________________________
+void AliTRDv1::CreateTRhit(Int_t det)
+{
+ //
+ // Creates an electron cluster from a TR photon.
+ // The photon is assumed to be created a the end of the radiator. The
+ // distance after which it deposits its energy takes into account the
+ // absorbtion of the entrance window and of the gas mixture in drift
+ // volume.
+ //
+
+ // Maximum number of TR photons per track
+ const Int_t kNTR = 50;
+
+ TLorentzVector mom;
+ TLorentzVector pos;
+
+ Float_t eTR[kNTR];
+ Int_t nTR;
+
+ // Create TR photons
+ gMC->TrackMomentum(mom);
+ Float_t pTot = mom.Rho();
+ fTR->CreatePhotons(11,pTot,nTR,eTR);
+ if (nTR > kNTR) {
+ AliFatal(Form("Boundary error: nTR = %d, kNTR = %d",nTR,kNTR));
+ }
+
+ // Loop through the TR photons
+ for (Int_t iTR = 0; iTR < nTR; iTR++) {
+
+ Float_t energyMeV = eTR[iTR] * 0.001;
+ Float_t energyeV = eTR[iTR] * 1000.0;
+ Float_t absLength = 0.0;
+ Float_t sigma = 0.0;
+
+ // Take the absorbtion in the entrance window into account
+ Double_t muMy = fTR->GetMuMy(energyMeV);
+ sigma = muMy * fFoilDensity;
+ if (sigma > 0.0) {
+ absLength = gRandom->Exp(1.0/sigma);
+ if (absLength < AliTRDgeometry::MyThick()) {
+ continue;
+ }
+ }
+ else {
+ continue;
+ }
+
+ // The absorbtion cross sections in the drift gas
+ // Gas-mixture (Xe/CO2)
+ Double_t muNo = 0.0;
+ if (AliTRDCommonParam::Instance()->IsXenon()) {
+ muNo = fTR->GetMuXe(energyMeV);
+ }
+ else if (AliTRDCommonParam::Instance()->IsArgon()) {
+ muNo = fTR->GetMuAr(energyMeV);
+ }
+ Double_t muCO = fTR->GetMuCO(energyMeV);
+ sigma = (fGasNobleFraction * muNo + (1.0 - fGasNobleFraction) * muCO)
+ * fGasDensity
+ * fTR->GetTemp();
+
+ // The distance after which the energy of the TR photon
+ // is deposited.
+ if (sigma > 0.0) {
+ absLength = gRandom->Exp(1.0/sigma);
+ if (absLength > (AliTRDgeometry::DrThick()
+ + AliTRDgeometry::AmThick())) {
+ continue;
+ }
+ }
+ else {
+ continue;
+ }
+
+ // The position of the absorbtion
+ Float_t posHit[3];
+ gMC->TrackPosition(pos);
+ posHit[0] = pos[0] + mom[0] / pTot * absLength;
+ posHit[1] = pos[1] + mom[1] / pTot * absLength;
+ posHit[2] = pos[2] + mom[2] / pTot * absLength;
+
+ // Create the charge
+ Int_t q = ((Int_t) (energyeV / fWion));
+
+ // Add the hit to the array. TR photon hits are marked
+ // by negative charge
+ AddHit(gAlice->GetMCApp()->GetCurrentTrackNumber()
+ ,det
+ ,posHit
+ ,-q
+ ,gMC->TrackTime()*1.0e06
+ ,kTRUE);
+
+ }
+
+}
+
//_____________________________________________________________________________
void AliTRDv1::Init()
{
//
- // Initialise the Transition Radiation Detector after the geometry is built
+ // Initialise Transition Radiation Detector after geometry has been built.
//
AliTRD::Init();
- for (Int_t i = 0; i < 80; i++) printf("*");
- printf("\n");
-
- // Identifier of the sensitive volume (amplification region)
- fIdSens = gMC->VolId("UL06");
+ AliDebug(1,"Slow simulator\n");
- // Identifier of the TRD-spaceframe volumina
- fIdSpace1 = gMC->VolId("B028");
- fIdSpace2 = gMC->VolId("B029");
- fIdSpace3 = gMC->VolId("B030");
+ // Switch on TR simulation as default
+ if (!fTRon) {
+ AliInfo("TR simulation off");
+ }
+ else {
+ fTR = new AliTRDsimTR();
+ }
- // Identifier of the TRD-driftchambers
- fIdChamber1 = gMC->VolId("UCIO");
- fIdChamber2 = gMC->VolId("UCIM");
- fIdChamber3 = gMC->VolId("UCII");
+ AliDebug(1,"+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++");
}
//_____________________________________________________________________________
-void AliTRDv1::StepManager()
+void AliTRDv1::StepManager()
{
//
- // Procedure called at every step in the TRD
- // Fast simulator. If switched on, a hit is produced when a track
- // crosses the border between amplification region and pad plane.
- //
-
- Int_t vol[3];
- Int_t iIdSens, icSens;
- Int_t iIdSpace, icSpace;
- Int_t iIdChamber, icChamber;
-
- Int_t secMap1[10] = { 3, 7, 8, 9, 10, 11, 2, 1, 18, 17 };
- Int_t secMap2[ 5] = { 16, 15, 14, 13, 12 };
- Int_t secMap3[ 3] = { 5, 6, 4 };
-
- Float_t hits[4];
-
- TLorentzVector p;
- TClonesArray &lhits = *fHits;
-
- // Writing out hits enabled?
- if (!(fHitsOn)) return;
-
- // Use only charged tracks and count them only once per volume
- if (gMC->TrackCharge() &&
- gMC->IsTrackExiting()) {
-
- // Check on sensitive volume
- iIdSens = gMC->CurrentVolID(icSens);
- if (iIdSens == fIdSens) {
-
- gMC->TrackPosition(p);
- for (Int_t i = 0; i < 3; i++) hits[i] = p[i];
- // No charge created
- hits[3] = 0;
-
- iIdSpace = gMC->CurrentVolOffID(4,icSpace );
- iIdChamber = gMC->CurrentVolOffID(1,icChamber);
-
- // The sector number
- if (iIdSpace == fIdSpace1)
- vol[0] = secMap1[icSpace-1];
- else if (iIdSpace == fIdSpace2)
- vol[0] = secMap2[icSpace-1];
- else if (iIdSpace == fIdSpace3)
- vol[0] = secMap3[icSpace-1];
-
- // The chamber number
- // 1: outer left
- // 2: middle left
- // 3: inner
- // 4: middle right
- // 5: outer right
- if (iIdChamber == fIdChamber1)
- vol[1] = (hits[2] < 0 ? 1 : 5);
- else if (iIdChamber == fIdChamber2)
- vol[1] = (hits[2] < 0 ? 2 : 4);
- else if (iIdChamber == fIdChamber3)
- vol[1] = 3;
-
- // The plane number
- vol[2] = icChamber - TMath::Nint((Float_t) (icChamber / 7)) * 6;
-
- new(lhits[fNhits++]) AliTRDhit(fIshunt,gAlice->CurrentTrack(),vol,hits);
+ // Slow simulator. Every charged track produces electron cluster as hits
+ // along its path across the drift volume. The step size is fixed in
+ // this version of the step manager.
+ //
+ // Works for Xe/CO2 as well as Ar/CO2
+ //
+ // PDG code electron
+ const Int_t kPdgElectron = 11;
+
+ Int_t layer = 0;
+ Int_t stack = 0;
+ Int_t sector = 0;
+ Int_t det = 0;
+ Int_t qTot;
+
+ Float_t hits[3];
+ Double_t eDep;
+
+ Bool_t drRegion = kFALSE;
+ Bool_t amRegion = kFALSE;
+
+ TString cIdPath;
+ Char_t cIdSector[3];
+ cIdSector[2] = 0;
+
+ TString cIdCurrent;
+ TString cIdSensDr = "J";
+ TString cIdSensAm = "K";
+ Char_t cIdChamber[3];
+ cIdChamber[2] = 0;
+
+ TLorentzVector pos;
+ TLorentzVector mom;
+
+ const Int_t kNlayer = AliTRDgeometry::Nlayer();
+ const Int_t kNstack = AliTRDgeometry::Nstack();
+ const Int_t kNdetsec = kNlayer * kNstack;
+
+ const Double_t kBig = 1.0e+12;
+ const Float_t kEkinMinStep = 1.0e-5; // Minimum energy for the step size adjustment
+
+ // Set the maximum step size to a very large number for all
+ // neutral particles and those outside the driftvolume
+ if (!fPrimaryIonisation) gMC->SetMaxStep(kBig);
+
+ // If not charged track or already stopped or disappeared, just return.
+ if ((!gMC->TrackCharge()) ||
+ gMC->IsTrackDisappeared()) {
+ return;
+ }
+
+ // Inside a sensitive volume?
+ cIdCurrent = gMC->CurrentVolName();
+
+ if (cIdSensDr == cIdCurrent[1]) {
+ drRegion = kTRUE;
+ }
+ if (cIdSensAm == cIdCurrent[1]) {
+ amRegion = kTRUE;
+ }
+
+ if ((!drRegion) &&
+ (!amRegion)) {
+ return;
+ }
+
+ // The hit coordinates and charge
+ gMC->TrackPosition(pos);
+ hits[0] = pos[0];
+ hits[1] = pos[1];
+ hits[2] = pos[2];
+
+ // The sector number (0 - 17), according to standard coordinate system
+ cIdPath = gGeoManager->GetPath();
+ cIdSector[0] = cIdPath[21];
+ cIdSector[1] = cIdPath[22];
+ sector = atoi(cIdSector);
+
+ // The plane and chamber number
+ cIdChamber[0] = cIdCurrent[2];
+ cIdChamber[1] = cIdCurrent[3];
+ Int_t idChamber = (atoi(cIdChamber) % kNdetsec);
+ stack = ((Int_t) idChamber / kNlayer);
+ layer = ((Int_t) idChamber % kNlayer);
+
+ // The detector number
+ det = fGeometry->GetDetector(layer,stack,sector);
+
+ // 0: InFlight 1:Entering 2:Exiting
+ Int_t trkStat = 0;
+
+ // Special hits only in the drift region
+ if ((drRegion) &&
+ (gMC->IsTrackEntering())) {
+
+ // Create a track reference at the entrance of each
+ // chamber that contains the momentum components of the particle
+ gMC->TrackMomentum(mom);
+ AddTrackReference(gAlice->GetMCApp()->GetCurrentTrackNumber(), AliTrackReference::kTRD);
+ trkStat = 1;
+
+ // Create the hits from TR photons if electron/positron is
+ // entering the drift volume
+ if ((fTR) &&
+ (fTRon) &&
+ (TMath::Abs(gMC->TrackPid()) == kPdgElectron)) {
+ CreateTRhit(det);
}
- }
+ }
+ else if ((amRegion) &&
+ (gMC->IsTrackExiting())) {
+
+ // Create a track reference at the exit of each
+ // chamber that contains the momentum components of the particle
+ gMC->TrackMomentum(mom);
+ AddTrackReference(gAlice->GetMCApp()->GetCurrentTrackNumber(), AliTrackReference::kTRD);
+ trkStat = 2;
+
+ }
+
+ // Calculate the charge according to GEANT Edep
+ // Create a new dEdx hit
+ eDep = TMath::Max(gMC->Edep(),0.0) * 1.0e+09;
+ qTot = (Int_t) (eDep / fWion);
+ if ((qTot) ||
+ (trkStat)) {
+ AddHit(gAlice->GetMCApp()->GetCurrentTrackNumber()
+ ,det
+ ,hits
+ ,qTot
+ ,gMC->TrackTime()*1.0e06
+ ,drRegion);
+ }
+
+ // Set Maximum Step Size
+ // Produce only one hit if Ekin is below cutoff
+ if ((gMC->Etot() - gMC->TrackMass()) < kEkinMinStep) {
+ return;
+ }
+ if (!fPrimaryIonisation) gMC->SetMaxStep(fStepSize);
}