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4 * Author: The ALICE Off-line Project. *
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18 /* History of cvs commits:
23 //_________________________________________________________________________
24 // Implementation version v1 of PHOS Manager class
27 // Layout EMC + CPV has name IHEP:
28 // Produces hits for CPV, cumulated hits
31 //*-- Author: Yves Schutz (SUBATECH)
34 // --- ROOT system ---
35 #include <TParticle.h>
36 #include <TVirtualMC.h>
38 // --- Standard library ---
41 // --- AliRoot header files ---
42 #include "AliPHOSCPVDigit.h"
43 #include "AliPHOSGeometry.h"
44 #include "AliPHOSHit.h"
45 #include "AliPHOSv1.h"
51 //____________________________________________________________________________
52 AliPHOSv1::AliPHOSv1():
56 fLightYieldMean = 0. ;
57 fIntrinsicPINEfficiency = 0. ;
58 fLightYieldAttenuation = 0. ;
59 fRecalibrationFactor = 0. ;
60 fElectronsPerGeV = 0. ;
67 //____________________________________________________________________________
68 AliPHOSv1::AliPHOSv1(const char *name, const char *title):
73 // - fHits (the "normal" one), which retains the hits associated with
74 // the current primary particle being tracked
75 // (this array is reset after each primary has been tracked).
80 // We do not want to save in TreeH the raw hits
81 // But save the cumulated hits instead (need to create the branch myself)
82 // It is put in the Digit Tree because the TreeH is filled after each primary
83 // and the TreeD at the end of the event (branch is set in FinishEvent() ).
85 fHits= new TClonesArray("AliPHOSHit",1000) ;
86 gAlice->GetMCApp()->AddHitList(fHits) ;
90 fIshunt = 2 ; // All hits are associated with primary particles
92 //Photoelectron statistics:
93 // The light yield is a poissonian distribution of the number of
94 // photons created in the PbWo4 crystal, calculated using following formula
95 // NumberOfPhotons = EnergyLost * LightYieldMean* APDEfficiency *
96 // exp (-LightYieldAttenuation * DistanceToPINdiodeFromTheHit);
97 // LightYieldMean is parameter calculated to be over 47000 photons per GeV
98 // APDEfficiency is 0.02655
99 // k_0 is 0.0045 from Valery Antonenko
100 // The number of electrons created in the APD is
101 // NumberOfElectrons = APDGain * LightYield
102 // The APD Gain is 300
103 fLightYieldMean = 47000;
104 fIntrinsicPINEfficiency = 0.02655 ; //APD= 0.1875/0.1271 * 0.018 (PIN)
105 fLightYieldAttenuation = 0.0045 ;
106 fRecalibrationFactor = 13.418/ fLightYieldMean ;
107 fElectronsPerGeV = 2.77e+8 ;
109 fLightFactor = fLightYieldMean * fIntrinsicPINEfficiency ;
110 fAPDFactor = (fRecalibrationFactor/100.) * fAPDGain ;
113 //____________________________________________________________________________
114 AliPHOSv1::~AliPHOSv1()
124 //____________________________________________________________________________
125 void AliPHOSv1::Copy(TObject & base)const
127 TObject::Copy(base) ;
128 AliPHOSv0::Copy(base) ;
129 AliPHOSv1 &phos = static_cast<AliPHOSv1 &>(base);
130 phos.fLightYieldMean = fLightYieldMean ;
131 phos.fIntrinsicPINEfficiency = fIntrinsicPINEfficiency ;
132 phos.fLightYieldAttenuation = fLightYieldAttenuation ;
133 phos.fRecalibrationFactor = fRecalibrationFactor ;
134 phos.fElectronsPerGeV = fElectronsPerGeV ;
135 phos.fAPDGain = fAPDGain ;
136 phos.fLightFactor = fLightFactor ;
137 phos.fAPDFactor = fAPDFactor ;
140 //____________________________________________________________________________
141 void AliPHOSv1::AddHit(Int_t shunt, Int_t primary, Int_t Id, Float_t * hits)
143 // Add a hit to the hit list.
144 // A PHOS hit is the sum of all hits in a single crystal from one primary and within some time gate
149 Bool_t deja = kFALSE ;
150 AliPHOSGeometry * geom = GetGeometry() ;
152 newHit = new AliPHOSHit(shunt, primary, Id, hits) ;
154 for ( hitCounter = fNhits-1 ; hitCounter >= 0 && !deja ; hitCounter-- ) {
155 curHit = dynamic_cast<AliPHOSHit*>((*fHits)[hitCounter]) ;
156 if(curHit->GetPrimary() != primary) break ;
157 // We add hits with the same primary, while GEANT treats primaries succesively
158 if( *curHit == *newHit ) {
165 new((*fHits)[fNhits]) AliPHOSHit(*newHit) ;
166 // get the block Id number
168 geom->AbsToRelNumbering(Id, relid) ;
176 //____________________________________________________________________________
177 void AliPHOSv1::FinishPrimary()
179 // called at the end of each track (primary) by AliRun
180 // hits are reset for each new track
181 // accumulate the total hit-multiplicity
185 //____________________________________________________________________________
186 void AliPHOSv1::FinishEvent()
188 // called at the end of each event by AliRun
189 // accumulate the hit-multiplicity and total energy per block
190 // if the values have been updated check it
192 AliDetector::FinishEvent();
194 //____________________________________________________________________________
195 void AliPHOSv1::StepManager(void)
197 // Accumulates hits as long as the track stays in a single crystal or CPV gas Cell
199 Int_t relid[4] ; // (box, layer, row, column) indices
200 Int_t absid ; // absolute cell ID number
201 Float_t xyzte[5]={-1000.,-1000.,-1000.,0.,0.} ; // position wrt MRS, time and energy deposited
202 TLorentzVector pos ; // Lorentz vector of the track current position
205 TString name = GetGeometry()->GetName() ;
209 static Int_t idPCPQ = gMC->VolId("PCPQ");
210 if( gMC->CurrentVolID(copy) == idPCPQ &&
211 (gMC->IsTrackEntering() ) &&
212 gMC->TrackCharge() != 0) {
214 gMC -> TrackPosition(pos);
216 Float_t xyzm[3], xyzd[3] ;
218 for (i=0; i<3; i++) xyzm[i] = pos[i];
219 gMC -> Gmtod (xyzm, xyzd, 1); // transform coordinate from master to daughter system
221 Float_t xyd[3]={0,0,0} ; //local position of the entering
226 // Current momentum of the hit's track in the local ref. system
227 TLorentzVector pmom ; //momentum of the particle initiated hit
228 gMC -> TrackMomentum(pmom);
229 Float_t pm[3], pd[3];
233 gMC -> Gmtod (pm, pd, 2); // transform 3-momentum from master to daughter system
238 // Digitize the current CPV hit:
240 // 1. find pad response and
241 gMC->CurrentVolOffID(3,moduleNumber);
244 TClonesArray *cpvDigits = new TClonesArray("AliPHOSCPVDigit",0); // array of digits for current hit
245 CPVDigitize(pmom,xyd,cpvDigits);
250 Int_t idigit,ndigits;
252 // 2. go through the current digit list and sum digits in pads
254 ndigits = cpvDigits->GetEntriesFast();
255 for (idigit=0; idigit<ndigits-1; idigit++) {
256 AliPHOSCPVDigit *cpvDigit1 = dynamic_cast<AliPHOSCPVDigit*>(cpvDigits->UncheckedAt(idigit));
257 Float_t x1 = cpvDigit1->GetXpad() ;
258 Float_t z1 = cpvDigit1->GetYpad() ;
259 for (Int_t jdigit=idigit+1; jdigit<ndigits; jdigit++) {
260 AliPHOSCPVDigit *cpvDigit2 = dynamic_cast<AliPHOSCPVDigit*>(cpvDigits->UncheckedAt(jdigit));
261 Float_t x2 = cpvDigit2->GetXpad() ;
262 Float_t z2 = cpvDigit2->GetYpad() ;
263 if (x1==x2 && z1==z2) {
264 Float_t qsum = cpvDigit1->GetQpad() + cpvDigit2->GetQpad() ;
265 cpvDigit2->SetQpad(qsum) ;
266 cpvDigits->RemoveAt(idigit) ;
270 cpvDigits->Compress() ;
272 // 3. add digits to temporary hit list fTmpHits
274 ndigits = cpvDigits->GetEntriesFast();
275 for (idigit=0; idigit<ndigits; idigit++) {
276 AliPHOSCPVDigit *cpvDigit = dynamic_cast<AliPHOSCPVDigit*>(cpvDigits->UncheckedAt(idigit));
277 relid[0] = moduleNumber + 1 ; // CPV (or PHOS) module number
278 relid[1] =-1 ; // means CPV
279 relid[2] = cpvDigit->GetXpad() ; // column number of a pad
280 relid[3] = cpvDigit->GetYpad() ; // row number of a pad
282 // get the absolute Id number
283 GetGeometry()->RelToAbsNumbering(relid, absid) ;
285 // add current digit to the temporary hit list
287 xyzte[3] = gMC->TrackTime() ;
288 xyzte[4] = cpvDigit->GetQpad() ; // amplitude in a pad
290 Int_t primary = gAlice->GetMCApp()->GetPrimary( gAlice->GetMCApp()->GetCurrentTrackNumber() );
291 AddHit(fIshunt, primary, absid, xyzte);
293 if (cpvDigit->GetQpad() > 0.02) {
294 xmean += cpvDigit->GetQpad() * (cpvDigit->GetXpad() + 0.5);
295 zmean += cpvDigit->GetQpad() * (cpvDigit->GetYpad() + 0.5);
296 qsum += cpvDigit->GetQpad();
307 static Int_t idPXTL = gMC->VolId("PXTL");
308 if(gMC->CurrentVolID(copy) == idPXTL ) { // We are inside a PBWO crystal
310 gMC->TrackPosition(pos) ;
315 Float_t global[3], local[3] ;
319 Float_t lostenergy = gMC->Edep();
321 //Put in the TreeK particle entering PHOS and all its parents
322 if ( gMC->IsTrackEntering() ){
324 gMC -> Gmtod (xyzte, xyzd, 1); // transform coordinate from master to daughter system
325 if (xyzd[1] < -GetGeometry()->GetCrystalSize(1)/2.+0.1){ //Entered close to forward surface
326 Int_t parent = gAlice->GetMCApp()->GetCurrentTrackNumber() ;
327 TParticle * part = gAlice->GetMCApp()->Particle(parent) ;
328 Float_t vert[3],vertd[3] ;
332 gMC -> Gmtod (vert, vertd, 1); // transform coordinate from master to daughter system
333 if(vertd[1]<-GetGeometry()->GetCrystalSize(1)/2.-0.1){ //Particle is created in foront of PHOS
334 //0.1 to get rid of numerical errors
335 part->SetBit(kKeepBit);
336 while ( parent != -1 ) {
337 part = gAlice->GetMCApp()->Particle(parent) ;
338 part->SetBit(kKeepBit);
339 parent = part->GetFirstMother() ;
344 if ( lostenergy != 0 ) { // Track is inside the crystal and deposits some energy
345 xyzte[3] = gMC->TrackTime() ;
347 gMC->CurrentVolOffID(10, moduleNumber) ; // get the PHOS module number ;
350 gMC->CurrentVolOffID(3, strip);
352 gMC->CurrentVolOffID(2, cell);
354 Int_t row = 1 + GetGeometry()->GetNZ() - strip % GetGeometry()->GetNZ() ;
355 Int_t col = (Int_t) TMath::Ceil((Double_t) strip/GetGeometry()->GetNZ()) -1 ;
357 absid = (moduleNumber-1)*GetGeometry()->GetNCristalsInModule() +
358 row + (col*GetGeometry()->GetEMCAGeometry()->GetNCellsInStrip() + cell-1)*GetGeometry()->GetNZ() ;
360 gMC->Gmtod(global, local, 1) ;
362 //Calculates the light yield, the number of photons produced in the
364 Float_t lightYield = gRandom->Poisson(fLightFactor * lostenergy *
365 exp(-fLightYieldAttenuation *
366 (local[1]+GetGeometry()->GetCrystalSize(1)/2.0 ))
369 //Calculates de energy deposited in the crystal
370 xyzte[4] = fAPDFactor * lightYield ;
374 primary = gAlice->GetMCApp()->GetCurrentTrackNumber() ;
375 TParticle * part = gAlice->GetMCApp()->Particle(primary) ;
376 while ( !part->TestBit(kKeepBit) ) {
377 primary = part->GetFirstMother() ;
379 primary = gAlice->GetMCApp()->GetPrimary( gAlice->GetMCApp()->GetCurrentTrackNumber() );
380 break ; //there is a possibility that particle passed e.g. thermal isulator and hits a side
381 //surface of the crystal. In this case it may have no primary at all.
382 //We can not easily separate this case from the case when this is part of the shower,
383 //developed in the neighboring crystal.
385 part = gAlice->GetMCApp()->Particle(primary) ;
389 primary = gAlice->GetMCApp()->GetPrimary( gAlice->GetMCApp()->GetCurrentTrackNumber() );
393 // add current hit to the hit list
394 // Info("StepManager","%d %d", primary, tracknumber) ;
395 AddHit(fIshunt, primary, absid, xyzte);
397 } // there is deposited energy
398 } // we are inside a PHOS Xtal
402 //____________________________________________________________________________
403 void AliPHOSv1::CPVDigitize (TLorentzVector p, Float_t *zxhit, TClonesArray *cpvDigits)
405 // ------------------------------------------------------------------------
406 // Digitize one CPV hit:
407 // On input take exact 4-momentum p and position zxhit of the hit,
408 // find the pad response around this hit and
409 // put the amplitudes in the pads into array digits
411 // Author: Yuri Kharlov (after Serguei Sadovsky)
413 // ------------------------------------------------------------------------
415 const Float_t kCelWr = GetGeometry()->GetPadSizePhi()/2; // Distance between wires (2 wires above 1 pad)
416 const Float_t kDetR = 0.1; // Relative energy fluctuation in track for 100 e-
417 const Float_t kdEdx = 4.0; // Average energy loss in CPV;
418 const Int_t kNgamz = 5; // Ionization size in Z
419 const Int_t kNgamx = 9; // Ionization size in Phi
420 const Float_t kNoise = 0.03; // charge noise in one pad
424 // Just a reminder on axes notation in the CPV module:
425 // axis Z goes along the beam
426 // axis X goes across the beam in the module plane
427 // axis Y is a normal to the module plane showing from the IP
429 Float_t hitX = zxhit[0];
430 Float_t hitZ =-zxhit[1];
433 Float_t pNorm = p.Py();
434 Float_t eloss = kdEdx;
436 //Info("CPVDigitize", "YVK : %f %f | %f %f %d", hitX, hitZ, pX, pZ, pNorm) ;
438 Float_t dZY = pZ/pNorm * GetGeometry()->GetCPVGasThickness();
439 Float_t dXY = pX/pNorm * GetGeometry()->GetCPVGasThickness();
440 gRandom->Rannor(rnor1,rnor2);
441 eloss *= (1 + kDetR*rnor1) *
442 TMath::Sqrt((1 + ( pow(dZY,2) + pow(dXY,2) ) / pow(GetGeometry()->GetCPVGasThickness(),2)));
443 Float_t zhit1 = hitZ + GetGeometry()->GetCPVActiveSize(1)/2 - dZY/2;
444 Float_t xhit1 = hitX + GetGeometry()->GetCPVActiveSize(0)/2 - dXY/2;
445 Float_t zhit2 = zhit1 + dZY;
446 Float_t xhit2 = xhit1 + dXY;
448 Int_t iwht1 = (Int_t) (xhit1 / kCelWr); // wire (x) coordinate "in"
449 Int_t iwht2 = (Int_t) (xhit2 / kCelWr); // wire (x) coordinate "out"
453 if (iwht1==iwht2) { // incline 1-wire hit
455 zxe[0][0] = (zhit1 + zhit2 - dZY*0.57735) / 2;
456 zxe[1][0] = (iwht1 + 0.5) * kCelWr;
458 zxe[0][1] = (zhit1 + zhit2 + dZY*0.57735) / 2;
459 zxe[1][1] = (iwht1 + 0.5) * kCelWr;
462 else if (TMath::Abs(iwht1-iwht2) != 1) { // incline 3-wire hit
464 Int_t iwht3 = (iwht1 + iwht2) / 2;
465 Float_t xwht1 = (iwht1 + 0.5) * kCelWr; // wire 1
466 Float_t xwht2 = (iwht2 + 0.5) * kCelWr; // wire 2
467 Float_t xwht3 = (iwht3 + 0.5) * kCelWr; // wire 3
468 Float_t xwr13 = (xwht1 + xwht3) / 2; // center 13
469 Float_t xwr23 = (xwht2 + xwht3) / 2; // center 23
470 Float_t dxw1 = xhit1 - xwr13;
471 Float_t dxw2 = xhit2 - xwr23;
472 Float_t egm1 = TMath::Abs(dxw1) / ( TMath::Abs(dxw1) + TMath::Abs(dxw2) + kCelWr );
473 Float_t egm2 = TMath::Abs(dxw2) / ( TMath::Abs(dxw1) + TMath::Abs(dxw2) + kCelWr );
474 Float_t egm3 = kCelWr / ( TMath::Abs(dxw1) + TMath::Abs(dxw2) + kCelWr );
475 zxe[0][0] = (dXY*(xwr13-xwht1)/dXY + zhit1 + zhit1) / 2;
477 zxe[2][0] = eloss * egm1;
478 zxe[0][1] = (dXY*(xwr23-xwht1)/dXY + zhit1 + zhit2) / 2;
480 zxe[2][1] = eloss * egm2;
481 zxe[0][2] = dXY*(xwht3-xwht1)/dXY + zhit1;
483 zxe[2][2] = eloss * egm3;
485 else { // incline 2-wire hit
487 Float_t xwht1 = (iwht1 + 0.5) * kCelWr;
488 Float_t xwht2 = (iwht2 + 0.5) * kCelWr;
489 Float_t xwr12 = (xwht1 + xwht2) / 2;
490 Float_t dxw1 = xhit1 - xwr12;
491 Float_t dxw2 = xhit2 - xwr12;
492 Float_t egm1 = TMath::Abs(dxw1) / ( TMath::Abs(dxw1) + TMath::Abs(dxw2) );
493 Float_t egm2 = TMath::Abs(dxw2) / ( TMath::Abs(dxw1) + TMath::Abs(dxw2) );
494 zxe[0][0] = (zhit1 + zhit2 - dZY*egm1) / 2;
496 zxe[2][0] = eloss * egm1;
497 zxe[0][1] = (zhit1 + zhit2 + dZY*egm2) / 2;
499 zxe[2][1] = eloss * egm2;
502 // Finite size of ionization region
504 Int_t nCellZ = GetGeometry()->GetNumberOfCPVPadsZ();
505 Int_t nCellX = GetGeometry()->GetNumberOfCPVPadsPhi();
506 Int_t nz3 = (kNgamz+1)/2;
507 Int_t nx3 = (kNgamx+1)/2;
508 cpvDigits->Expand(nIter*kNgamx*kNgamz);
509 TClonesArray &ldigits = *(static_cast<TClonesArray *>(cpvDigits));
511 for (Int_t iter=0; iter<nIter; iter++) {
513 Float_t zhit = zxe[0][iter];
514 Float_t xhit = zxe[1][iter];
515 Float_t qhit = zxe[2][iter];
516 Float_t zcell = zhit / GetGeometry()->GetPadSizeZ();
517 Float_t xcell = xhit / GetGeometry()->GetPadSizePhi();
518 if ( zcell<=0 || xcell<=0 ||
519 zcell>=nCellZ || xcell>=nCellX) return;
520 Int_t izcell = (Int_t) zcell;
521 Int_t ixcell = (Int_t) xcell;
522 Float_t zc = zcell - izcell - 0.5;
523 Float_t xc = xcell - ixcell - 0.5;
524 for (Int_t iz=1; iz<=kNgamz; iz++) {
525 Int_t kzg = izcell + iz - nz3;
526 if (kzg<=0 || kzg>nCellZ) continue;
527 Float_t zg = (Float_t)(iz-nz3) - zc;
528 for (Int_t ix=1; ix<=kNgamx; ix++) {
529 Int_t kxg = ixcell + ix - nx3;
530 if (kxg<=0 || kxg>nCellX) continue;
531 Float_t xg = (Float_t)(ix-nx3) - xc;
533 // Now calculate pad response
534 Float_t qpad = CPVPadResponseFunction(qhit,zg,xg);
535 qpad += kNoise*rnor2;
536 if (qpad<0) continue;
538 // Fill the array with pad response ID and amplitude
539 new(ldigits[cpvDigits->GetEntriesFast()]) AliPHOSCPVDigit(kxg,kzg,qpad);
545 //____________________________________________________________________________
546 Float_t AliPHOSv1::CPVPadResponseFunction(Float_t qhit, Float_t zhit, Float_t xhit) {
547 // ------------------------------------------------------------------------
548 // Calculate the amplitude in one CPV pad using the
549 // cumulative pad response function
550 // Author: Yuri Kharlov (after Serguei Sadovski)
552 // ------------------------------------------------------------------------
554 Double_t dz = GetGeometry()->GetPadSizeZ() / 2;
555 Double_t dx = GetGeometry()->GetPadSizePhi() / 2;
556 Double_t z = zhit * GetGeometry()->GetPadSizeZ();
557 Double_t x = xhit * GetGeometry()->GetPadSizePhi();
558 Double_t amplitude = qhit *
559 (CPVCumulPadResponse(z+dz,x+dx) - CPVCumulPadResponse(z+dz,x-dx) -
560 CPVCumulPadResponse(z-dz,x+dx) + CPVCumulPadResponse(z-dz,x-dx));
561 return (Float_t)amplitude;
564 //____________________________________________________________________________
565 Double_t AliPHOSv1::CPVCumulPadResponse(Double_t x, Double_t y) {
566 // ------------------------------------------------------------------------
567 // Cumulative pad response function
568 // It includes several terms from the CF decomposition in electrostatics
569 // Note: this cumulative function is wrong since omits some terms
570 // but the cell amplitude obtained with it is correct because
571 // these omitting terms cancel
572 // Author: Yuri Kharlov (after Serguei Sadovski)
574 // ------------------------------------------------------------------------
576 const Double_t kA=1.0;
577 const Double_t kB=0.7;
579 Double_t r2 = x*x + y*y;
581 Double_t cumulPRF = 0;
582 for (Int_t i=0; i<=4; i++) {
583 Double_t b1 = (2*i + 1) * kB;
584 cumulPRF += TMath::Power(-1,i) * TMath::ATan( xy / (b1*TMath::Sqrt(b1*b1 + r2)) );
586 cumulPRF *= kA/(2*TMath::Pi());