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18 /* History of cvs commits:
21 * Revision 1.105 2006/09/13 07:31:01 kharlov
22 * Effective C++ corrections (T.Pocheptsov)
24 * Revision 1.104 2005/05/28 14:19:05 schutz
25 * Compilation warnings fixed by T.P.
29 //_________________________________________________________________________
30 // Implementation version v1 of PHOS Manager class
33 // Layout EMC + CPV has name IHEP:
34 // Produces hits for CPV, cumulated hits
37 //*-- Author: Yves Schutz (SUBATECH)
40 // --- ROOT system ---
41 #include <TParticle.h>
42 #include <TVirtualMC.h>
44 // --- Standard library ---
47 // --- AliRoot header files ---
48 #include "AliPHOSCPVDigit.h"
49 #include "AliPHOSGeometry.h"
50 #include "AliPHOSHit.h"
51 #include "AliPHOSv1.h"
57 //____________________________________________________________________________
58 AliPHOSv1::AliPHOSv1():
60 fIntrinsicPINEfficiency(0.),
61 fLightYieldAttenuation(0.),
62 fRecalibrationFactor(0.),
71 //____________________________________________________________________________
72 AliPHOSv1::AliPHOSv1(const char *name, const char *title):
73 AliPHOSv0(name,title),
75 fIntrinsicPINEfficiency(0.),
76 fLightYieldAttenuation(0.),
77 fRecalibrationFactor(0.),
85 // - fHits (the "normal" one), which retains the hits associated with
86 // the current primary particle being tracked
87 // (this array is reset after each primary has been tracked).
92 // We do not want to save in TreeH the raw hits
93 // But save the cumulated hits instead (need to create the branch myself)
94 // It is put in the Digit Tree because the TreeH is filled after each primary
95 // and the TreeD at the end of the event (branch is set in FinishEvent() ).
97 fHits= new TClonesArray("AliPHOSHit",1000) ;
98 gAlice->GetMCApp()->AddHitList(fHits) ;
102 fIshunt = 2 ; // All hits are associated with primary particles
104 //Photoelectron statistics:
105 // The light yield is a poissonian distribution of the number of
106 // photons created in the PbWo4 crystal, calculated using following formula
107 // NumberOfPhotons = EnergyLost * LightYieldMean* APDEfficiency *
108 // exp (-LightYieldAttenuation * DistanceToPINdiodeFromTheHit);
109 // LightYieldMean is parameter calculated to be over 47000 photons per GeV
110 // APDEfficiency is 0.02655
111 // k_0 is 0.0045 from Valery Antonenko
112 // The number of electrons created in the APD is
113 // NumberOfElectrons = APDGain * LightYield
114 // The APD Gain is 300
115 fLightYieldMean = 47000;
116 fIntrinsicPINEfficiency = 0.02655 ; //APD= 0.1875/0.1271 * 0.018 (PIN)
117 fLightYieldAttenuation = 0.0045 ;
118 fRecalibrationFactor = 13.418/ fLightYieldMean ;
119 fElectronsPerGeV = 2.77e+8 ;
121 fLightFactor = fLightYieldMean * fIntrinsicPINEfficiency ;
122 fAPDFactor = (fRecalibrationFactor/100.) * fAPDGain ;
125 //____________________________________________________________________________
126 AliPHOSv1::~AliPHOSv1()
136 //____________________________________________________________________________
137 void AliPHOSv1::AddHit(Int_t shunt, Int_t primary, Int_t Id, Float_t * hits)
139 // Add a hit to the hit list.
140 // A PHOS hit is the sum of all hits in a single crystal from one primary and within some time gate
145 Bool_t deja = kFALSE ;
146 AliPHOSGeometry * geom = GetGeometry() ;
148 newHit = new AliPHOSHit(shunt, primary, Id, hits) ;
150 for ( hitCounter = fNhits-1 ; hitCounter >= 0 && !deja ; hitCounter-- ) {
151 curHit = dynamic_cast<AliPHOSHit*>((*fHits)[hitCounter]) ;
152 if(curHit->GetPrimary() != primary) break ;
153 // We add hits with the same primary, while GEANT treats primaries succesively
154 if( *curHit == *newHit ) {
161 new((*fHits)[fNhits]) AliPHOSHit(*newHit) ;
162 // get the block Id number
164 geom->AbsToRelNumbering(Id, relid) ;
172 //____________________________________________________________________________
173 void AliPHOSv1::FinishPrimary()
175 // called at the end of each track (primary) by AliRun
176 // hits are reset for each new track
177 // accumulate the total hit-multiplicity
181 //____________________________________________________________________________
182 void AliPHOSv1::FinishEvent()
184 // called at the end of each event by AliRun
185 // accumulate the hit-multiplicity and total energy per block
186 // if the values have been updated check it
188 AliDetector::FinishEvent();
190 //____________________________________________________________________________
191 void AliPHOSv1::StepManager(void)
193 // Accumulates hits as long as the track stays in a single crystal or CPV gas Cell
195 Int_t relid[4] ; // (box, layer, row, column) indices
196 Int_t absid ; // absolute cell ID number
197 Float_t xyzte[5]={-1000.,-1000.,-1000.,0.,0.} ; // position wrt MRS, time and energy deposited
198 TLorentzVector pos ; // Lorentz vector of the track current position
201 TString name = GetGeometry()->GetName() ;
205 static Int_t idPCPQ = gMC->VolId("PCPQ");
206 if( gMC->CurrentVolID(copy) == idPCPQ &&
207 (gMC->IsTrackEntering() ) &&
208 gMC->TrackCharge() != 0) {
210 gMC -> TrackPosition(pos);
212 Float_t xyzm[3], xyzd[3] ;
214 for (i=0; i<3; i++) xyzm[i] = pos[i];
215 gMC -> Gmtod (xyzm, xyzd, 1); // transform coordinate from master to daughter system
217 Float_t xyd[3]={0,0,0} ; //local position of the entering
222 // Current momentum of the hit's track in the local ref. system
223 TLorentzVector pmom ; //momentum of the particle initiated hit
224 gMC -> TrackMomentum(pmom);
225 Float_t pm[3], pd[3];
229 gMC -> Gmtod (pm, pd, 2); // transform 3-momentum from master to daughter system
234 // Digitize the current CPV hit:
236 // 1. find pad response and
237 gMC->CurrentVolOffID(3,moduleNumber);
240 TClonesArray *cpvDigits = new TClonesArray("AliPHOSCPVDigit",0); // array of digits for current hit
241 CPVDigitize(pmom,xyd,cpvDigits);
246 Int_t idigit,ndigits;
248 // 2. go through the current digit list and sum digits in pads
250 ndigits = cpvDigits->GetEntriesFast();
251 for (idigit=0; idigit<ndigits-1; idigit++) {
252 AliPHOSCPVDigit *cpvDigit1 = dynamic_cast<AliPHOSCPVDigit*>(cpvDigits->UncheckedAt(idigit));
253 Float_t x1 = cpvDigit1->GetXpad() ;
254 Float_t z1 = cpvDigit1->GetYpad() ;
255 for (Int_t jdigit=idigit+1; jdigit<ndigits; jdigit++) {
256 AliPHOSCPVDigit *cpvDigit2 = dynamic_cast<AliPHOSCPVDigit*>(cpvDigits->UncheckedAt(jdigit));
257 Float_t x2 = cpvDigit2->GetXpad() ;
258 Float_t z2 = cpvDigit2->GetYpad() ;
259 if (x1==x2 && z1==z2) {
260 Float_t qsum = cpvDigit1->GetQpad() + cpvDigit2->GetQpad() ;
261 cpvDigit2->SetQpad(qsum) ;
262 cpvDigits->RemoveAt(idigit) ;
266 cpvDigits->Compress() ;
268 // 3. add digits to temporary hit list fTmpHits
270 ndigits = cpvDigits->GetEntriesFast();
271 for (idigit=0; idigit<ndigits; idigit++) {
272 AliPHOSCPVDigit *cpvDigit = dynamic_cast<AliPHOSCPVDigit*>(cpvDigits->UncheckedAt(idigit));
273 relid[0] = moduleNumber + 1 ; // CPV (or PHOS) module number
274 relid[1] =-1 ; // means CPV
275 relid[2] = cpvDigit->GetXpad() ; // column number of a pad
276 relid[3] = cpvDigit->GetYpad() ; // row number of a pad
278 // get the absolute Id number
279 GetGeometry()->RelToAbsNumbering(relid, absid) ;
281 // add current digit to the temporary hit list
283 xyzte[3] = gMC->TrackTime() ;
284 xyzte[4] = cpvDigit->GetQpad() ; // amplitude in a pad
286 Int_t primary = gAlice->GetMCApp()->GetPrimary( gAlice->GetMCApp()->GetCurrentTrackNumber() );
287 AddHit(fIshunt, primary, absid, xyzte);
289 if (cpvDigit->GetQpad() > 0.02) {
290 xmean += cpvDigit->GetQpad() * (cpvDigit->GetXpad() + 0.5);
291 zmean += cpvDigit->GetQpad() * (cpvDigit->GetYpad() + 0.5);
292 qsum += cpvDigit->GetQpad();
303 static Int_t idPXTL = gMC->VolId("PXTL");
304 if(gMC->CurrentVolID(copy) == idPXTL ) { // We are inside a PBWO crystal
306 gMC->TrackPosition(pos) ;
311 Float_t global[3], local[3] ;
315 Float_t lostenergy = gMC->Edep();
317 //Put in the TreeK particle entering PHOS and all its parents
318 if ( gMC->IsTrackEntering() ){
320 gMC -> Gmtod (xyzte, xyzd, 1); // transform coordinate from master to daughter system
321 if (xyzd[1] < -GetGeometry()->GetCrystalSize(1)/2.+0.1){ //Entered close to forward surface
322 Int_t parent = gAlice->GetMCApp()->GetCurrentTrackNumber() ;
323 TParticle * part = gAlice->GetMCApp()->Particle(parent) ;
324 Float_t vert[3],vertd[3] ;
328 gMC -> Gmtod (vert, vertd, 1); // transform coordinate from master to daughter system
329 if(vertd[1]<-GetGeometry()->GetCrystalSize(1)/2.-0.1){ //Particle is created in foront of PHOS
330 //0.1 to get rid of numerical errors
331 part->SetBit(kKeepBit);
332 while ( parent != -1 ) {
333 part = gAlice->GetMCApp()->Particle(parent) ;
334 part->SetBit(kKeepBit);
335 parent = part->GetFirstMother() ;
340 if ( lostenergy != 0 ) { // Track is inside the crystal and deposits some energy
341 xyzte[3] = gMC->TrackTime() ;
343 gMC->CurrentVolOffID(10, moduleNumber) ; // get the PHOS module number ;
346 gMC->CurrentVolOffID(3, strip);
348 gMC->CurrentVolOffID(2, cell);
350 Int_t row = 1 + GetGeometry()->GetNZ() - strip % GetGeometry()->GetNZ() ;
351 Int_t col = (Int_t) TMath::Ceil((Double_t) strip/GetGeometry()->GetNZ()) -1 ;
353 absid = (moduleNumber-1)*GetGeometry()->GetNCristalsInModule() +
354 row + (col*GetGeometry()->GetEMCAGeometry()->GetNCellsInStrip() + cell-1)*GetGeometry()->GetNZ() ;
356 gMC->Gmtod(global, local, 1) ;
358 //Calculates the light yield, the number of photons produced in the
360 Float_t lightYield = gRandom->Poisson(fLightFactor * lostenergy *
361 exp(-fLightYieldAttenuation *
362 (local[1]+GetGeometry()->GetCrystalSize(1)/2.0 ))
365 //Calculates de energy deposited in the crystal
366 xyzte[4] = fAPDFactor * lightYield ;
370 primary = gAlice->GetMCApp()->GetCurrentTrackNumber() ;
371 TParticle * part = gAlice->GetMCApp()->Particle(primary) ;
372 while ( !part->TestBit(kKeepBit) ) {
373 primary = part->GetFirstMother() ;
375 primary = gAlice->GetMCApp()->GetPrimary( gAlice->GetMCApp()->GetCurrentTrackNumber() );
376 break ; //there is a possibility that particle passed e.g. thermal isulator and hits a side
377 //surface of the crystal. In this case it may have no primary at all.
378 //We can not easily separate this case from the case when this is part of the shower,
379 //developed in the neighboring crystal.
381 part = gAlice->GetMCApp()->Particle(primary) ;
385 primary = gAlice->GetMCApp()->GetPrimary( gAlice->GetMCApp()->GetCurrentTrackNumber() );
389 // add current hit to the hit list
390 // Info("StepManager","%d %d", primary, tracknumber) ;
391 AddHit(fIshunt, primary, absid, xyzte);
393 } // there is deposited energy
394 } // we are inside a PHOS Xtal
398 //____________________________________________________________________________
399 void AliPHOSv1::CPVDigitize (TLorentzVector p, Float_t *zxhit, TClonesArray *cpvDigits)
401 // ------------------------------------------------------------------------
402 // Digitize one CPV hit:
403 // On input take exact 4-momentum p and position zxhit of the hit,
404 // find the pad response around this hit and
405 // put the amplitudes in the pads into array digits
407 // Author: Yuri Kharlov (after Serguei Sadovsky)
409 // ------------------------------------------------------------------------
411 const Float_t kCelWr = GetGeometry()->GetPadSizePhi()/2; // Distance between wires (2 wires above 1 pad)
412 const Float_t kDetR = 0.1; // Relative energy fluctuation in track for 100 e-
413 const Float_t kdEdx = 4.0; // Average energy loss in CPV;
414 const Int_t kNgamz = 5; // Ionization size in Z
415 const Int_t kNgamx = 9; // Ionization size in Phi
416 const Float_t kNoise = 0.03; // charge noise in one pad
420 // Just a reminder on axes notation in the CPV module:
421 // axis Z goes along the beam
422 // axis X goes across the beam in the module plane
423 // axis Y is a normal to the module plane showing from the IP
425 Float_t hitX = zxhit[0];
426 Float_t hitZ =-zxhit[1];
429 Float_t pNorm = p.Py();
430 Float_t eloss = kdEdx;
432 //Info("CPVDigitize", "YVK : %f %f | %f %f %d", hitX, hitZ, pX, pZ, pNorm) ;
434 Float_t dZY = pZ/pNorm * GetGeometry()->GetCPVGasThickness();
435 Float_t dXY = pX/pNorm * GetGeometry()->GetCPVGasThickness();
436 gRandom->Rannor(rnor1,rnor2);
437 eloss *= (1 + kDetR*rnor1) *
438 TMath::Sqrt((1 + ( pow(dZY,2) + pow(dXY,2) ) / pow(GetGeometry()->GetCPVGasThickness(),2)));
439 Float_t zhit1 = hitZ + GetGeometry()->GetCPVActiveSize(1)/2 - dZY/2;
440 Float_t xhit1 = hitX + GetGeometry()->GetCPVActiveSize(0)/2 - dXY/2;
441 Float_t zhit2 = zhit1 + dZY;
442 Float_t xhit2 = xhit1 + dXY;
444 Int_t iwht1 = (Int_t) (xhit1 / kCelWr); // wire (x) coordinate "in"
445 Int_t iwht2 = (Int_t) (xhit2 / kCelWr); // wire (x) coordinate "out"
449 if (iwht1==iwht2) { // incline 1-wire hit
451 zxe[0][0] = (zhit1 + zhit2 - dZY*0.57735) / 2;
452 zxe[1][0] = (iwht1 + 0.5) * kCelWr;
454 zxe[0][1] = (zhit1 + zhit2 + dZY*0.57735) / 2;
455 zxe[1][1] = (iwht1 + 0.5) * kCelWr;
458 else if (TMath::Abs(iwht1-iwht2) != 1) { // incline 3-wire hit
460 Int_t iwht3 = (iwht1 + iwht2) / 2;
461 Float_t xwht1 = (iwht1 + 0.5) * kCelWr; // wire 1
462 Float_t xwht2 = (iwht2 + 0.5) * kCelWr; // wire 2
463 Float_t xwht3 = (iwht3 + 0.5) * kCelWr; // wire 3
464 Float_t xwr13 = (xwht1 + xwht3) / 2; // center 13
465 Float_t xwr23 = (xwht2 + xwht3) / 2; // center 23
466 Float_t dxw1 = xhit1 - xwr13;
467 Float_t dxw2 = xhit2 - xwr23;
468 Float_t egm1 = TMath::Abs(dxw1) / ( TMath::Abs(dxw1) + TMath::Abs(dxw2) + kCelWr );
469 Float_t egm2 = TMath::Abs(dxw2) / ( TMath::Abs(dxw1) + TMath::Abs(dxw2) + kCelWr );
470 Float_t egm3 = kCelWr / ( TMath::Abs(dxw1) + TMath::Abs(dxw2) + kCelWr );
471 zxe[0][0] = (dXY*(xwr13-xwht1)/dXY + zhit1 + zhit1) / 2;
473 zxe[2][0] = eloss * egm1;
474 zxe[0][1] = (dXY*(xwr23-xwht1)/dXY + zhit1 + zhit2) / 2;
476 zxe[2][1] = eloss * egm2;
477 zxe[0][2] = dXY*(xwht3-xwht1)/dXY + zhit1;
479 zxe[2][2] = eloss * egm3;
481 else { // incline 2-wire hit
483 Float_t xwht1 = (iwht1 + 0.5) * kCelWr;
484 Float_t xwht2 = (iwht2 + 0.5) * kCelWr;
485 Float_t xwr12 = (xwht1 + xwht2) / 2;
486 Float_t dxw1 = xhit1 - xwr12;
487 Float_t dxw2 = xhit2 - xwr12;
488 Float_t egm1 = TMath::Abs(dxw1) / ( TMath::Abs(dxw1) + TMath::Abs(dxw2) );
489 Float_t egm2 = TMath::Abs(dxw2) / ( TMath::Abs(dxw1) + TMath::Abs(dxw2) );
490 zxe[0][0] = (zhit1 + zhit2 - dZY*egm1) / 2;
492 zxe[2][0] = eloss * egm1;
493 zxe[0][1] = (zhit1 + zhit2 + dZY*egm2) / 2;
495 zxe[2][1] = eloss * egm2;
498 // Finite size of ionization region
500 Int_t nCellZ = GetGeometry()->GetNumberOfCPVPadsZ();
501 Int_t nCellX = GetGeometry()->GetNumberOfCPVPadsPhi();
502 Int_t nz3 = (kNgamz+1)/2;
503 Int_t nx3 = (kNgamx+1)/2;
504 cpvDigits->Expand(nIter*kNgamx*kNgamz);
505 TClonesArray &ldigits = *(static_cast<TClonesArray *>(cpvDigits));
507 for (Int_t iter=0; iter<nIter; iter++) {
509 Float_t zhit = zxe[0][iter];
510 Float_t xhit = zxe[1][iter];
511 Float_t qhit = zxe[2][iter];
512 Float_t zcell = zhit / GetGeometry()->GetPadSizeZ();
513 Float_t xcell = xhit / GetGeometry()->GetPadSizePhi();
514 if ( zcell<=0 || xcell<=0 ||
515 zcell>=nCellZ || xcell>=nCellX) return;
516 Int_t izcell = (Int_t) zcell;
517 Int_t ixcell = (Int_t) xcell;
518 Float_t zc = zcell - izcell - 0.5;
519 Float_t xc = xcell - ixcell - 0.5;
520 for (Int_t iz=1; iz<=kNgamz; iz++) {
521 Int_t kzg = izcell + iz - nz3;
522 if (kzg<=0 || kzg>nCellZ) continue;
523 Float_t zg = (Float_t)(iz-nz3) - zc;
524 for (Int_t ix=1; ix<=kNgamx; ix++) {
525 Int_t kxg = ixcell + ix - nx3;
526 if (kxg<=0 || kxg>nCellX) continue;
527 Float_t xg = (Float_t)(ix-nx3) - xc;
529 // Now calculate pad response
530 Float_t qpad = CPVPadResponseFunction(qhit,zg,xg);
531 qpad += kNoise*rnor2;
532 if (qpad<0) continue;
534 // Fill the array with pad response ID and amplitude
535 new(ldigits[cpvDigits->GetEntriesFast()]) AliPHOSCPVDigit(kxg,kzg,qpad);
541 //____________________________________________________________________________
542 Float_t AliPHOSv1::CPVPadResponseFunction(Float_t qhit, Float_t zhit, Float_t xhit) {
543 // ------------------------------------------------------------------------
544 // Calculate the amplitude in one CPV pad using the
545 // cumulative pad response function
546 // Author: Yuri Kharlov (after Serguei Sadovski)
548 // ------------------------------------------------------------------------
550 Double_t dz = GetGeometry()->GetPadSizeZ() / 2;
551 Double_t dx = GetGeometry()->GetPadSizePhi() / 2;
552 Double_t z = zhit * GetGeometry()->GetPadSizeZ();
553 Double_t x = xhit * GetGeometry()->GetPadSizePhi();
554 Double_t amplitude = qhit *
555 (CPVCumulPadResponse(z+dz,x+dx) - CPVCumulPadResponse(z+dz,x-dx) -
556 CPVCumulPadResponse(z-dz,x+dx) + CPVCumulPadResponse(z-dz,x-dx));
557 return (Float_t)amplitude;
560 //____________________________________________________________________________
561 Double_t AliPHOSv1::CPVCumulPadResponse(Double_t x, Double_t y) {
562 // ------------------------------------------------------------------------
563 // Cumulative pad response function
564 // It includes several terms from the CF decomposition in electrostatics
565 // Note: this cumulative function is wrong since omits some terms
566 // but the cell amplitude obtained with it is correct because
567 // these omitting terms cancel
568 // Author: Yuri Kharlov (after Serguei Sadovski)
570 // ------------------------------------------------------------------------
572 const Double_t kA=1.0;
573 const Double_t kB=0.7;
575 Double_t r2 = x*x + y*y;
577 Double_t cumulPRF = 0;
578 for (Int_t i=0; i<=4; i++) {
579 Double_t b1 = (2*i + 1) * kB;
580 cumulPRF += TMath::Power(-1,i) * TMath::ATan( xy / (b1*TMath::Sqrt(b1*b1 + r2)) );
582 cumulPRF *= kA/(2*TMath::Pi());