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4 * Author: The ALICE Off-line Project. *
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18 //_________________________________________________________________________
19 // Implementation version v1 of PHOS Manager class
22 // Layout EMC + CPV has name IHEP:
23 // Produces hits for CPV, cumulated hits
26 //*-- Author: Yves Schutz (SUBATECH)
29 // --- ROOT system ---
30 #include <TParticle.h>
31 #include <TVirtualMC.h>
33 // --- Standard library ---
36 // --- AliRoot header files ---
37 #include "AliPHOSCPVDigit.h"
38 #include "AliPHOSGeometry.h"
39 #include "AliPHOSHit.h"
40 #include "AliPHOSQAFloatCheckable.h"
41 #include "AliPHOSQAIntCheckable.h"
42 #include "AliPHOSQAMeanChecker.h"
43 #include "AliPHOSv1.h"
49 //____________________________________________________________________________
50 AliPHOSv1::AliPHOSv1():
53 // default ctor: initialze data memebers
59 fLightYieldMean = 0. ;
60 fIntrinsicPINEfficiency = 0. ;
61 fLightYieldAttenuation = 0. ;
62 fRecalibrationFactor = 0. ;
63 fElectronsPerGeV = 0. ;
70 //____________________________________________________________________________
71 AliPHOSv1::AliPHOSv1(const char *name, const char *title):
76 // - fHits (the "normal" one), which retains the hits associated with
77 // the current primary particle being tracked
78 // (this array is reset after each primary has been tracked).
83 // We do not want to save in TreeH the raw hits
84 // But save the cumulated hits instead (need to create the branch myself)
85 // It is put in the Digit Tree because the TreeH is filled after each primary
86 // and the TreeD at the end of the event (branch is set in FinishEvent() ).
88 fHits= new TClonesArray("AliPHOSHit",1000) ;
89 gAlice->GetMCApp()->AddHitList(fHits) ;
93 fIshunt = 2 ; // All hits are associated with primary particles
95 //Photoelectron statistics:
96 // The light yield is a poissonian distribution of the number of
97 // photons created in the PbWo4 crystal, calculated using following formula
98 // NumberOfPhotons = EnergyLost * LightYieldMean* APDEfficiency *
99 // exp (-LightYieldAttenuation * DistanceToPINdiodeFromTheHit);
100 // LightYieldMean is parameter calculated to be over 47000 photons per GeV
101 // APDEfficiency is 0.02655
102 // k_0 is 0.0045 from Valery Antonenko
103 // The number of electrons created in the APD is
104 // NumberOfElectrons = APDGain * LightYield
105 // The APD Gain is 300
106 fLightYieldMean = 47000;
107 fIntrinsicPINEfficiency = 0.02655 ; //APD= 0.1875/0.1271 * 0.018 (PIN)
108 fLightYieldAttenuation = 0.0045 ;
109 fRecalibrationFactor = 13.418/ fLightYieldMean ;
110 fElectronsPerGeV = 2.77e+8 ;
112 fLightFactor = fLightYieldMean * fIntrinsicPINEfficiency ;
113 fAPDFactor = (fRecalibrationFactor/100.) * fAPDGain ;
116 Int_t nb = GetGeometry()->GetNModules() ;
119 fQAHitsMul = new AliPHOSQAIntCheckable("HitsM") ;
120 fQATotEner = new AliPHOSQAFloatCheckable("TotEn") ;
121 fQAHitsMulB = new TClonesArray("AliPHOSQAIntCheckable",nb) ;
122 fQAHitsMulB->SetOwner() ;
123 fQATotEnerB = new TClonesArray("AliPHOSQAFloatCheckable", nb);
124 fQATotEnerB->SetOwner() ;
127 for ( i = 0 ; i < nb ; i++ ) {
128 sprintf(tempo, "HitsMB%d", i+1) ;
129 new( (*fQAHitsMulB)[i]) AliPHOSQAIntCheckable(tempo) ;
130 sprintf(tempo, "TotEnB%d", i+1) ;
131 new( (*fQATotEnerB)[i] ) AliPHOSQAFloatCheckable(tempo) ;
134 AliPHOSQAMeanChecker * hmc = new AliPHOSQAMeanChecker("HitsMul", 100. ,25.) ;
135 AliPHOSQAMeanChecker * emc = new AliPHOSQAMeanChecker("TotEner", 10. ,5.) ;
136 AliPHOSQAMeanChecker * bhmc = new AliPHOSQAMeanChecker("HitsMulB", 100. ,5.) ;
137 AliPHOSQAMeanChecker * bemc = new AliPHOSQAMeanChecker("TotEnerB", 2. ,.5) ;
139 // associate checkables and checkers
140 fQAHitsMul->AddChecker(hmc) ;
141 fQATotEner->AddChecker(emc) ;
142 for ( i = 0 ; i < nb ; i++ ) {
143 (static_cast<AliPHOSQAIntCheckable*>((*fQAHitsMulB)[i]))->AddChecker(bhmc) ;
144 (static_cast<AliPHOSQAFloatCheckable*>((*fQATotEnerB)[i]))->AddChecker(bemc) ;
149 //____________________________________________________________________________
150 AliPHOSv1::~AliPHOSv1()
160 fQAHitsMulB->Delete() ;
165 fQATotEnerB->Delete() ;
171 //____________________________________________________________________________
172 void AliPHOSv1::Copy(AliPHOSv1 & phos)
174 TObject::Copy(phos) ;
175 AliPHOSv0::Copy(phos) ;
176 phos.fLightYieldMean = fLightYieldMean ;
177 phos.fIntrinsicPINEfficiency = fIntrinsicPINEfficiency ;
178 phos.fLightYieldAttenuation = fLightYieldAttenuation ;
179 phos.fRecalibrationFactor = fRecalibrationFactor ;
180 phos.fElectronsPerGeV = fElectronsPerGeV ;
181 phos.fAPDGain = fAPDGain ;
182 phos.fLightFactor = fLightFactor ;
183 phos.fAPDFactor = fAPDFactor ;
186 //____________________________________________________________________________
187 void AliPHOSv1::AddHit(Int_t shunt, Int_t primary, Int_t Id, Float_t * hits)
189 // Add a hit to the hit list.
190 // A PHOS hit is the sum of all hits in a single crystal from one primary and within some time gate
195 Bool_t deja = kFALSE ;
196 AliPHOSGeometry * geom = GetGeometry() ;
198 newHit = new AliPHOSHit(shunt, primary, Id, hits) ;
200 for ( hitCounter = fNhits-1 ; hitCounter >= 0 && !deja ; hitCounter-- ) {
201 curHit = dynamic_cast<AliPHOSHit*>((*fHits)[hitCounter]) ;
202 if(curHit->GetPrimary() != primary) break ;
203 // We add hits with the same primary, while GEANT treats primaries succesively
204 if( *curHit == *newHit ) {
211 new((*fHits)[fNhits]) AliPHOSHit(*newHit) ;
212 // get the block Id number
214 geom->AbsToRelNumbering(Id, relid) ;
215 // and fill the relevant QA checkable (only if in PbW04)
216 if ( relid[1] == 0 ) {
217 fQAHitsMul->Update(1) ;
218 (static_cast<AliPHOSQAIntCheckable*>((*fQAHitsMulB)[relid[0]-1]))->Update(1) ;
226 //____________________________________________________________________________
227 void AliPHOSv1::FinishPrimary()
229 // called at the end of each track (primary) by AliRun
230 // hits are reset for each new track
231 // accumulate the total hit-multiplicity
233 // fQAHitsMul->Update( fHits->GetEntriesFast() ) ;
237 //____________________________________________________________________________
238 void AliPHOSv1::FinishEvent()
240 // called at the end of each event by AliRun
241 // accumulate the hit-multiplicity and total energy per block
242 // if the values have been updated check it
246 if ( fQATotEner->HasChanged() ) {
247 fQATotEner->CheckMe() ;
248 fQATotEner->Reset() ;
253 if ( fQAHitsMulB && fQATotEnerB ) {
254 for (i = 0 ; i < GetGeometry()->GetNModules() ; i++) {
255 AliPHOSQAIntCheckable * ci = static_cast<AliPHOSQAIntCheckable*>((*fQAHitsMulB)[i]) ;
256 AliPHOSQAFloatCheckable* cf = static_cast<AliPHOSQAFloatCheckable*>((*fQATotEnerB)[i]) ;
257 if ( ci->HasChanged() ) {
261 if ( cf->HasChanged() ) {
268 // check the total multiplicity
271 if ( fQAHitsMul->HasChanged() ) {
272 fQAHitsMul->CheckMe() ;
273 fQAHitsMul->Reset() ;
277 AliDetector::FinishEvent();
279 //____________________________________________________________________________
280 void AliPHOSv1::StepManager(void)
282 // Accumulates hits as long as the track stays in a single crystal or CPV gas Cell
284 Int_t relid[4] ; // (box, layer, row, column) indices
285 Int_t absid ; // absolute cell ID number
286 Float_t xyzte[5]={-1000.,-1000.,-1000.,0.,0.} ; // position wrt MRS, time and energy deposited
287 TLorentzVector pos ; // Lorentz vector of the track current position
290 TString name = GetGeometry()->GetName() ;
294 static Int_t idPCPQ = gMC->VolId("PCPQ");
295 if( gMC->CurrentVolID(copy) == idPCPQ &&
296 (gMC->IsTrackEntering() ) &&
297 gMC->TrackCharge() != 0) {
299 gMC -> TrackPosition(pos);
301 Float_t xyzm[3], xyzd[3] ;
303 for (i=0; i<3; i++) xyzm[i] = pos[i];
304 gMC -> Gmtod (xyzm, xyzd, 1); // transform coordinate from master to daughter system
306 Float_t xyd[3]={0,0,0} ; //local position of the entering
311 // Current momentum of the hit's track in the local ref. system
312 TLorentzVector pmom ; //momentum of the particle initiated hit
313 gMC -> TrackMomentum(pmom);
314 Float_t pm[3], pd[3];
318 gMC -> Gmtod (pm, pd, 2); // transform 3-momentum from master to daughter system
323 // Digitize the current CPV hit:
325 // 1. find pad response and
326 gMC->CurrentVolOffID(3,moduleNumber);
329 TClonesArray *cpvDigits = new TClonesArray("AliPHOSCPVDigit",0); // array of digits for current hit
330 CPVDigitize(pmom,xyd,cpvDigits);
335 Int_t idigit,ndigits;
337 // 2. go through the current digit list and sum digits in pads
339 ndigits = cpvDigits->GetEntriesFast();
340 for (idigit=0; idigit<ndigits-1; idigit++) {
341 AliPHOSCPVDigit *cpvDigit1 = dynamic_cast<AliPHOSCPVDigit*>(cpvDigits->UncheckedAt(idigit));
342 Float_t x1 = cpvDigit1->GetXpad() ;
343 Float_t z1 = cpvDigit1->GetYpad() ;
344 for (Int_t jdigit=idigit+1; jdigit<ndigits; jdigit++) {
345 AliPHOSCPVDigit *cpvDigit2 = dynamic_cast<AliPHOSCPVDigit*>(cpvDigits->UncheckedAt(jdigit));
346 Float_t x2 = cpvDigit2->GetXpad() ;
347 Float_t z2 = cpvDigit2->GetYpad() ;
348 if (x1==x2 && z1==z2) {
349 Float_t qsum = cpvDigit1->GetQpad() + cpvDigit2->GetQpad() ;
350 cpvDigit2->SetQpad(qsum) ;
351 cpvDigits->RemoveAt(idigit) ;
355 cpvDigits->Compress() ;
357 // 3. add digits to temporary hit list fTmpHits
359 ndigits = cpvDigits->GetEntriesFast();
360 for (idigit=0; idigit<ndigits; idigit++) {
361 AliPHOSCPVDigit *cpvDigit = dynamic_cast<AliPHOSCPVDigit*>(cpvDigits->UncheckedAt(idigit));
362 relid[0] = moduleNumber + 1 ; // CPV (or PHOS) module number
363 relid[1] =-1 ; // means CPV
364 relid[2] = cpvDigit->GetXpad() ; // column number of a pad
365 relid[3] = cpvDigit->GetYpad() ; // row number of a pad
367 // get the absolute Id number
368 GetGeometry()->RelToAbsNumbering(relid, absid) ;
370 // add current digit to the temporary hit list
372 xyzte[3] = gMC->TrackTime() ;
373 xyzte[4] = cpvDigit->GetQpad() ; // amplitude in a pad
375 Int_t primary = gAlice->GetMCApp()->GetPrimary( gAlice->GetMCApp()->GetCurrentTrackNumber() );
376 AddHit(fIshunt, primary, absid, xyzte);
378 if (cpvDigit->GetQpad() > 0.02) {
379 xmean += cpvDigit->GetQpad() * (cpvDigit->GetXpad() + 0.5);
380 zmean += cpvDigit->GetQpad() * (cpvDigit->GetYpad() + 0.5);
381 qsum += cpvDigit->GetQpad();
392 static Int_t idPXTL = gMC->VolId("PXTL");
393 if(gMC->CurrentVolID(copy) == idPXTL ) { // We are inside a PBWO crystal
395 gMC->TrackPosition(pos) ;
400 Float_t global[3], local[3] ;
404 Float_t lostenergy = gMC->Edep();
406 //Put in the TreeK particle entering PHOS and all its parents
407 if ( gMC->IsTrackEntering() ){
409 gMC -> Gmtod (xyzte, xyzd, 1); // transform coordinate from master to daughter system
410 if (xyzd[1] < -GetGeometry()->GetCrystalSize(1)/2.+0.1){ //Entered close to forward surface
411 Int_t parent = gAlice->GetMCApp()->GetCurrentTrackNumber() ;
412 TParticle * part = gAlice->GetMCApp()->Particle(parent) ;
413 Float_t vert[3],vertd[3] ;
417 gMC -> Gmtod (vert, vertd, 1); // transform coordinate from master to daughter system
418 if(vertd[1]<-GetGeometry()->GetCrystalSize(1)/2.-0.1){ //Particle is created in foront of PHOS
419 //0.1 to get rid of numerical errors
420 part->SetBit(kKeepBit);
421 while ( parent != -1 ) {
422 part = gAlice->GetMCApp()->Particle(parent) ;
423 part->SetBit(kKeepBit);
424 parent = part->GetFirstMother() ;
429 if ( lostenergy != 0 ) { // Track is inside the crystal and deposits some energy
430 xyzte[3] = gMC->TrackTime() ;
432 gMC->CurrentVolOffID(10, moduleNumber) ; // get the PHOS module number ;
435 gMC->CurrentVolOffID(3, strip);
437 gMC->CurrentVolOffID(2, cell);
439 Int_t row = 1 + GetGeometry()->GetNZ() - strip % GetGeometry()->GetNZ() ;
440 Int_t col = (Int_t) TMath::Ceil((Double_t) strip/GetGeometry()->GetNZ()) -1 ;
442 absid = (moduleNumber-1)*GetGeometry()->GetNCristalsInModule() +
443 row + (col*GetGeometry()->GetEMCAGeometry()->GetNCellsInStrip() + cell-1)*GetGeometry()->GetNZ() ;
445 gMC->Gmtod(global, local, 1) ;
447 //Calculates the light yield, the number of photons produced in the
449 Float_t lightYield = gRandom->Poisson(fLightFactor * lostenergy *
450 exp(-fLightYieldAttenuation *
451 (local[1]+GetGeometry()->GetCrystalSize(1)/2.0 ))
454 //Calculates de energy deposited in the crystal
455 xyzte[4] = fAPDFactor * lightYield ;
459 primary = gAlice->GetMCApp()->GetCurrentTrackNumber() ;
460 TParticle * part = gAlice->GetMCApp()->Particle(primary) ;
461 while ( !part->TestBit(kKeepBit) ) {
462 primary = part->GetFirstMother() ;
464 primary = gAlice->GetMCApp()->GetPrimary( gAlice->GetMCApp()->GetCurrentTrackNumber() );
465 break ; //there is a possibility that particle passed e.g. thermal isulator and hits a side
466 //surface of the crystal. In this case it may have no primary at all.
467 //We can not easily separate this case from the case when this is part of the shower,
468 //developed in the neighboring crystal.
470 part = gAlice->GetMCApp()->Particle(primary) ;
474 primary = gAlice->GetMCApp()->GetPrimary( gAlice->GetMCApp()->GetCurrentTrackNumber() );
478 // add current hit to the hit list
479 // Info("StepManager","%d %d", primary, tracknumber) ;
480 AddHit(fIshunt, primary, absid, xyzte);
482 // fill the relevant QA Checkables
483 fQATotEner->Update( xyzte[4] ) ; // total energy in PHOS
484 (static_cast<AliPHOSQAFloatCheckable*>((*fQATotEnerB)[moduleNumber-1]))->Update( xyzte[4] ) ; // energy in this block
486 } // there is deposited energy
487 } // we are inside a PHOS Xtal
491 //____________________________________________________________________________
492 void AliPHOSv1::CPVDigitize (TLorentzVector p, Float_t *zxhit, TClonesArray *cpvDigits)
494 // ------------------------------------------------------------------------
495 // Digitize one CPV hit:
496 // On input take exact 4-momentum p and position zxhit of the hit,
497 // find the pad response around this hit and
498 // put the amplitudes in the pads into array digits
500 // Author: Yuri Kharlov (after Serguei Sadovsky)
502 // ------------------------------------------------------------------------
504 const Float_t kCelWr = GetGeometry()->GetPadSizePhi()/2; // Distance between wires (2 wires above 1 pad)
505 const Float_t kDetR = 0.1; // Relative energy fluctuation in track for 100 e-
506 const Float_t kdEdx = 4.0; // Average energy loss in CPV;
507 const Int_t kNgamz = 5; // Ionization size in Z
508 const Int_t kNgamx = 9; // Ionization size in Phi
509 const Float_t kNoise = 0.03; // charge noise in one pad
513 // Just a reminder on axes notation in the CPV module:
514 // axis Z goes along the beam
515 // axis X goes across the beam in the module plane
516 // axis Y is a normal to the module plane showing from the IP
518 Float_t hitX = zxhit[0];
519 Float_t hitZ =-zxhit[1];
522 Float_t pNorm = p.Py();
523 Float_t eloss = kdEdx;
525 //Info("CPVDigitize", "YVK : %f %f | %f %f %d", hitX, hitZ, pX, pZ, pNorm) ;
527 Float_t dZY = pZ/pNorm * GetGeometry()->GetCPVGasThickness();
528 Float_t dXY = pX/pNorm * GetGeometry()->GetCPVGasThickness();
529 gRandom->Rannor(rnor1,rnor2);
530 eloss *= (1 + kDetR*rnor1) *
531 TMath::Sqrt((1 + ( pow(dZY,2) + pow(dXY,2) ) / pow(GetGeometry()->GetCPVGasThickness(),2)));
532 Float_t zhit1 = hitZ + GetGeometry()->GetCPVActiveSize(1)/2 - dZY/2;
533 Float_t xhit1 = hitX + GetGeometry()->GetCPVActiveSize(0)/2 - dXY/2;
534 Float_t zhit2 = zhit1 + dZY;
535 Float_t xhit2 = xhit1 + dXY;
537 Int_t iwht1 = (Int_t) (xhit1 / kCelWr); // wire (x) coordinate "in"
538 Int_t iwht2 = (Int_t) (xhit2 / kCelWr); // wire (x) coordinate "out"
542 if (iwht1==iwht2) { // incline 1-wire hit
544 zxe[0][0] = (zhit1 + zhit2 - dZY*0.57735) / 2;
545 zxe[1][0] = (iwht1 + 0.5) * kCelWr;
547 zxe[0][1] = (zhit1 + zhit2 + dZY*0.57735) / 2;
548 zxe[1][1] = (iwht1 + 0.5) * kCelWr;
551 else if (TMath::Abs(iwht1-iwht2) != 1) { // incline 3-wire hit
553 Int_t iwht3 = (iwht1 + iwht2) / 2;
554 Float_t xwht1 = (iwht1 + 0.5) * kCelWr; // wire 1
555 Float_t xwht2 = (iwht2 + 0.5) * kCelWr; // wire 2
556 Float_t xwht3 = (iwht3 + 0.5) * kCelWr; // wire 3
557 Float_t xwr13 = (xwht1 + xwht3) / 2; // center 13
558 Float_t xwr23 = (xwht2 + xwht3) / 2; // center 23
559 Float_t dxw1 = xhit1 - xwr13;
560 Float_t dxw2 = xhit2 - xwr23;
561 Float_t egm1 = TMath::Abs(dxw1) / ( TMath::Abs(dxw1) + TMath::Abs(dxw2) + kCelWr );
562 Float_t egm2 = TMath::Abs(dxw2) / ( TMath::Abs(dxw1) + TMath::Abs(dxw2) + kCelWr );
563 Float_t egm3 = kCelWr / ( TMath::Abs(dxw1) + TMath::Abs(dxw2) + kCelWr );
564 zxe[0][0] = (dXY*(xwr13-xwht1)/dXY + zhit1 + zhit1) / 2;
566 zxe[2][0] = eloss * egm1;
567 zxe[0][1] = (dXY*(xwr23-xwht1)/dXY + zhit1 + zhit2) / 2;
569 zxe[2][1] = eloss * egm2;
570 zxe[0][2] = dXY*(xwht3-xwht1)/dXY + zhit1;
572 zxe[2][2] = eloss * egm3;
574 else { // incline 2-wire hit
576 Float_t xwht1 = (iwht1 + 0.5) * kCelWr;
577 Float_t xwht2 = (iwht2 + 0.5) * kCelWr;
578 Float_t xwr12 = (xwht1 + xwht2) / 2;
579 Float_t dxw1 = xhit1 - xwr12;
580 Float_t dxw2 = xhit2 - xwr12;
581 Float_t egm1 = TMath::Abs(dxw1) / ( TMath::Abs(dxw1) + TMath::Abs(dxw2) );
582 Float_t egm2 = TMath::Abs(dxw2) / ( TMath::Abs(dxw1) + TMath::Abs(dxw2) );
583 zxe[0][0] = (zhit1 + zhit2 - dZY*egm1) / 2;
585 zxe[2][0] = eloss * egm1;
586 zxe[0][1] = (zhit1 + zhit2 + dZY*egm2) / 2;
588 zxe[2][1] = eloss * egm2;
591 // Finite size of ionization region
593 Int_t nCellZ = GetGeometry()->GetNumberOfCPVPadsZ();
594 Int_t nCellX = GetGeometry()->GetNumberOfCPVPadsPhi();
595 Int_t nz3 = (kNgamz+1)/2;
596 Int_t nx3 = (kNgamx+1)/2;
597 cpvDigits->Expand(nIter*kNgamx*kNgamz);
598 TClonesArray &ldigits = *(static_cast<TClonesArray *>(cpvDigits));
600 for (Int_t iter=0; iter<nIter; iter++) {
602 Float_t zhit = zxe[0][iter];
603 Float_t xhit = zxe[1][iter];
604 Float_t qhit = zxe[2][iter];
605 Float_t zcell = zhit / GetGeometry()->GetPadSizeZ();
606 Float_t xcell = xhit / GetGeometry()->GetPadSizePhi();
607 if ( zcell<=0 || xcell<=0 ||
608 zcell>=nCellZ || xcell>=nCellX) return;
609 Int_t izcell = (Int_t) zcell;
610 Int_t ixcell = (Int_t) xcell;
611 Float_t zc = zcell - izcell - 0.5;
612 Float_t xc = xcell - ixcell - 0.5;
613 for (Int_t iz=1; iz<=kNgamz; iz++) {
614 Int_t kzg = izcell + iz - nz3;
615 if (kzg<=0 || kzg>nCellZ) continue;
616 Float_t zg = (Float_t)(iz-nz3) - zc;
617 for (Int_t ix=1; ix<=kNgamx; ix++) {
618 Int_t kxg = ixcell + ix - nx3;
619 if (kxg<=0 || kxg>nCellX) continue;
620 Float_t xg = (Float_t)(ix-nx3) - xc;
622 // Now calculate pad response
623 Float_t qpad = CPVPadResponseFunction(qhit,zg,xg);
624 qpad += kNoise*rnor2;
625 if (qpad<0) continue;
627 // Fill the array with pad response ID and amplitude
628 new(ldigits[cpvDigits->GetEntriesFast()]) AliPHOSCPVDigit(kxg,kzg,qpad);
634 //____________________________________________________________________________
635 Float_t AliPHOSv1::CPVPadResponseFunction(Float_t qhit, Float_t zhit, Float_t xhit) {
636 // ------------------------------------------------------------------------
637 // Calculate the amplitude in one CPV pad using the
638 // cumulative pad response function
639 // Author: Yuri Kharlov (after Serguei Sadovski)
641 // ------------------------------------------------------------------------
643 Double_t dz = GetGeometry()->GetPadSizeZ() / 2;
644 Double_t dx = GetGeometry()->GetPadSizePhi() / 2;
645 Double_t z = zhit * GetGeometry()->GetPadSizeZ();
646 Double_t x = xhit * GetGeometry()->GetPadSizePhi();
647 Double_t amplitude = qhit *
648 (CPVCumulPadResponse(z+dz,x+dx) - CPVCumulPadResponse(z+dz,x-dx) -
649 CPVCumulPadResponse(z-dz,x+dx) + CPVCumulPadResponse(z-dz,x-dx));
650 return (Float_t)amplitude;
653 //____________________________________________________________________________
654 Double_t AliPHOSv1::CPVCumulPadResponse(Double_t x, Double_t y) {
655 // ------------------------------------------------------------------------
656 // Cumulative pad response function
657 // It includes several terms from the CF decomposition in electrostatics
658 // Note: this cumulative function is wrong since omits some terms
659 // but the cell amplitude obtained with it is correct because
660 // these omitting terms cancel
661 // Author: Yuri Kharlov (after Serguei Sadovski)
663 // ------------------------------------------------------------------------
665 const Double_t kA=1.0;
666 const Double_t kB=0.7;
668 Double_t r2 = x*x + y*y;
670 Double_t cumulPRF = 0;
671 for (Int_t i=0; i<=4; i++) {
672 Double_t b1 = (2*i + 1) * kB;
673 cumulPRF += TMath::Power(-1,i) * TMath::ATan( xy / (b1*TMath::Sqrt(b1*b1 + r2)) );
675 cumulPRF *= kA/(2*TMath::Pi());