1 /**************************************************************************
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4 * Author: The ALICE Off-line Project. *
5 * Contributors are mentioned in the code where appropriate. *
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14 **************************************************************************/
18 //_________________________________________________________________________
19 // Implementation version v1 of PHOS Manager class
21 // Layout EMC + PPSD has name GPS2:
22 // Produces cumulated hits
24 // Layout EMC + CPV has name IHEP:
25 // Produces hits for CPV, cumulated hits
27 // Layout EMC + CPV + PPSD has name GPS:
28 // Produces hits for CPV, cumulated hits
30 //*-- Author: Yves Schutz (SUBATECH)
33 // --- ROOT system ---
41 // --- Standard library ---
46 #include <strstream.h>
48 // --- AliRoot header files ---
50 #include "AliPHOSv1.h"
51 #include "AliPHOSHit.h"
52 #include "AliPHOSCPVDigit.h"
56 #include "AliPHOSGeometry.h"
60 //____________________________________________________________________________
61 AliPHOSv1::AliPHOSv1():
68 //____________________________________________________________________________
69 AliPHOSv1::AliPHOSv1(const char *name, const char *title):
72 // ctor : title is used to identify the layout
73 // GPS2 = 5 modules (EMC + PPSD)
74 // IHEP = 5 modules (EMC + CPV )
75 // MIXT = 4 modules (EMC + CPV ) and 1 module (EMC + PPSD)
78 // - fHits (the "normal" one), which retains the hits associated with
79 // the current primary particle being tracked
80 // (this array is reset after each primary has been tracked).
85 // We do not want to save in TreeH the raw hits
86 // But save the cumulated hits instead (need to create the branch myself)
87 // It is put in the Digit Tree because the TreeH is filled after each primary
88 // and the TreeD at the end of the event (branch is set in FinishEvent() ).
90 fHits= new TClonesArray("AliPHOSHit",1000) ;
94 fIshunt = 1 ; // All hits are associated with primary particles
98 //____________________________________________________________________________
99 // AliPHOSv1::AliPHOSv1(AliPHOSReconstructioner * Reconstructioner, const char *name, const char *title):
100 // AliPHOSv0(name,title)
102 // // ctor : title is used to identify the layout
103 // // GPS2 = 5 modules (EMC + PPSD)
105 // fPinElectronicNoise = 0.010 ;
107 // // We do not want to save in TreeH the raw hits
110 // fHits= new TClonesArray("AliPHOSHit",1000) ;
114 // fIshunt = 1 ; // All hits are associated with primary particles
116 // // gets an instance of the geometry parameters class
117 // fGeom = AliPHOSGeometry::GetInstance(title, "") ;
119 // if (fGeom->IsInitialized() )
120 // cout << "AliPHOS" << Version() << " : PHOS geometry intialized for " << fGeom->GetName() << endl ;
122 // cout << "AliPHOS" << Version() << " : PHOS geometry initialization failed !" << endl ;
124 // // Defining the PHOS Reconstructioner
126 // fReconstructioner = Reconstructioner ;
130 //____________________________________________________________________________
131 AliPHOSv1::~AliPHOSv1()
142 //____________________________________________________________________________
143 void AliPHOSv1::AddHit(Int_t shunt, Int_t primary, Int_t tracknumber, Int_t Id, Float_t * hits)
145 // Add a hit to the hit list.
146 // A PHOS hit is the sum of all hits in a single crystal
147 // or in a single PPSD gas cell
152 Bool_t deja = kFALSE ;
154 newHit = new AliPHOSHit(shunt, primary, tracknumber, Id, hits) ;
156 for ( hitCounter = fNhits-1 ; hitCounter >= 0 && !deja ; hitCounter-- ) {
157 curHit = (AliPHOSHit*) (*fHits)[hitCounter] ;
158 if(curHit->GetPrimary() != primary) break ; // We add hits with the same primary, while GEANT treats primaries consequently
159 if( *curHit == *newHit ) {
160 *curHit = *curHit + *newHit ;
166 new((*fHits)[fNhits]) AliPHOSHit(*newHit) ;
173 //____________________________________________________________________________
175 void AliPHOSv1::StepManager(void)
177 // Accumulates hits as long as the track stays in a single crystal or PPSD gas Cell
179 Int_t relid[4] ; // (box, layer, row, column) indices
180 Int_t absid ; // absolute cell ID number
181 Float_t xyze[4]={0,0,0,0} ; // position wrt MRS and energy deposited
182 TLorentzVector pos ; // Lorentz vector of the track current position
185 Int_t tracknumber = gAlice->CurrentTrack() ;
186 Int_t primary = gAlice->GetPrimary( gAlice->CurrentTrack() );
187 TString name = fGeom->GetName() ;
190 if ( name == "GPS2" || name == "MIXT" ) { // ======> CPV is a GPS' PPSD
192 if( gMC->CurrentVolID(copy) == gMC->VolId("PCEL") ) // We are inside a gas cell
194 gMC->TrackPosition(pos) ;
198 xyze[3] = gMC->Edep() ;
200 if ( xyze[3] != 0 ) { // there is deposited energy
201 gMC->CurrentVolOffID(5, relid[0]) ; // get the PHOS Module number
202 if ( name == "MIXT" && strcmp(gMC->CurrentVolOffName(5),"PHO1") == 0 ){
203 relid[0] += fGeom->GetNModules() - fGeom->GetNPPSDModules();
205 gMC->CurrentVolOffID(3, relid[1]) ; // get the Micromegas Module number
206 // 1-> fGeom->GetNumberOfModulesPhi() * fGeom->GetNumberOfModulesZ() upper
207 // > fGeom->GetNumberOfModulesPhi() * fGeom->GetNumberOfModulesZ() lower
208 gMC->CurrentVolOffID(1, relid[2]) ; // get the row number of the cell
209 gMC->CurrentVolID(relid[3]) ; // get the column number
211 // get the absolute Id number
213 fGeom->RelToAbsNumbering(relid, absid) ;
215 // add current hit to the hit list
216 AddHit(fIshunt, primary, tracknumber, absid, xyze);
219 } // there is deposited energy
220 } // We are inside the gas of the CPV
221 } // GPS2 configuration
223 if ( name == "IHEP" || name == "MIXT" ) { // ======> CPV is a IHEP's one
225 // Yuri Kharlov, 28 September 2000
227 if( gMC->CurrentVolID(copy) == gMC->VolId("PCPQ") &&
228 (gMC->IsTrackEntering() ) &&
229 gMC->TrackCharge() != 0) {
231 gMC -> TrackPosition(pos);
232 Float_t xyzm[3], xyzd[3] ;
234 for (i=0; i<3; i++) xyzm[i] = pos[i];
235 gMC -> Gmtod (xyzm, xyzd, 1); // transform coordinate from master to daughter system
237 Float_t xyd[3]={0,0,0} ; //local posiiton of the entering
243 // Current momentum of the hit's track in the local ref. system
244 TLorentzVector pmom ; //momentum of the particle initiated hit
245 gMC -> TrackMomentum(pmom);
246 Float_t pm[3], pd[3];
247 for (i=0; i<3; i++) pm[i] = pmom[i];
248 gMC -> Gmtod (pm, pd, 2); // transform 3-momentum from master to daughter system
253 // Digitize the current CPV hit:
255 // 1. find pad response and
258 gMC->CurrentVolOffID(3,moduleNumber);
262 TClonesArray *cpvDigits = new TClonesArray("AliPHOSCPVDigit",0); // array of digits for current hit
263 CPVDigitize(pmom,xyd,moduleNumber,cpvDigits);
268 Int_t idigit,ndigits;
270 // 2. go through the current digit list and sum digits in pads
272 ndigits = cpvDigits->GetEntriesFast();
273 for (idigit=0; idigit<ndigits-1; idigit++) {
274 AliPHOSCPVDigit *cpvDigit1 = (AliPHOSCPVDigit*) cpvDigits->UncheckedAt(idigit);
275 Float_t x1 = cpvDigit1->GetXpad() ;
276 Float_t z1 = cpvDigit1->GetYpad() ;
277 for (Int_t jdigit=idigit+1; jdigit<ndigits; jdigit++) {
278 AliPHOSCPVDigit *cpvDigit2 = (AliPHOSCPVDigit*) cpvDigits->UncheckedAt(jdigit);
279 Float_t x2 = cpvDigit2->GetXpad() ;
280 Float_t z2 = cpvDigit2->GetYpad() ;
281 if (x1==x2 && z1==z2) {
282 Float_t qsum = cpvDigit1->GetQpad() + cpvDigit2->GetQpad() ;
283 cpvDigit2->SetQpad(qsum) ;
284 cpvDigits->RemoveAt(idigit) ;
288 cpvDigits->Compress() ;
290 // 3. add digits to temporary hit list fTmpHits
292 ndigits = cpvDigits->GetEntriesFast();
293 for (idigit=0; idigit<ndigits; idigit++) {
294 AliPHOSCPVDigit *cpvDigit = (AliPHOSCPVDigit*) cpvDigits->UncheckedAt(idigit);
295 relid[0] = moduleNumber + 1 ; // CPV (or PHOS) module number
296 relid[1] =-1 ; // means CPV
297 relid[2] = cpvDigit->GetXpad() ; // column number of a pad
298 relid[3] = cpvDigit->GetYpad() ; // row number of a pad
300 // get the absolute Id number
301 fGeom->RelToAbsNumbering(relid, absid) ;
303 // add current digit to the temporary hit list
307 xyze[3] = cpvDigit->GetQpad() ; // amplitude in a pad
308 primary = -1; // No need in primary for CPV
309 AddHit(fIshunt, primary, tracknumber, absid, xyze);
311 if (cpvDigit->GetQpad() > 0.02) {
312 xmean += cpvDigit->GetQpad() * (cpvDigit->GetXpad() + 0.5);
313 zmean += cpvDigit->GetQpad() * (cpvDigit->GetYpad() + 0.5);
314 qsum += cpvDigit->GetQpad();
319 } // end of IHEP configuration
322 if(gMC->CurrentVolID(copy) == gMC->VolId("PXTL") ) { // We are inside a PBWO crystal
323 gMC->TrackPosition(pos) ;
327 xyze[3] = gMC->Edep() ;
330 if ( xyze[3] != 0 ) { // Track is inside the crystal and deposits some energy
332 gMC->CurrentVolOffID(10, relid[0]) ; // get the PHOS module number ;
334 if ( name == "MIXT" && strcmp(gMC->CurrentVolOffName(10),"PHO1") == 0 )
335 relid[0] += fGeom->GetNModules() - fGeom->GetNPPSDModules();
337 relid[1] = 0 ; // means PBW04
338 gMC->CurrentVolOffID(4, relid[2]) ; // get the row number inside the module
339 gMC->CurrentVolOffID(3, relid[3]) ; // get the cell number inside the module
341 // get the absolute Id number
342 fGeom->RelToAbsNumbering(relid, absid) ;
344 // add current hit to the hit list
345 AddHit(fIshunt, primary,tracknumber, absid, xyze);
348 } // there is deposited energy
349 } // we are inside a PHOS Xtal
354 //____________________________________________________________________________
355 void AliPHOSv1::CPVDigitize (TLorentzVector p, Float_t *zxhit, Int_t moduleNumber, TClonesArray *cpvDigits)
357 // ------------------------------------------------------------------------
358 // Digitize one CPV hit:
359 // On input take exact 4-momentum p and position zxhit of the hit,
360 // find the pad response around this hit and
361 // put the amplitudes in the pads into array digits
363 // Author: Yuri Kharlov (after Serguei Sadovsky)
365 // ------------------------------------------------------------------------
367 const Float_t kCelWr = fGeom->GetPadSizePhi()/2; // Distance between wires (2 wires above 1 pad)
368 const Float_t kDetR = 0.1; // Relative energy fluctuation in track for 100 e-
369 const Float_t kdEdx = 4.0; // Average energy loss in CPV;
370 const Int_t kNgamz = 5; // Ionization size in Z
371 const Int_t kNgamx = 9; // Ionization size in Phi
372 const Float_t kNoise = 0.03; // charge noise in one pad
376 // Just a reminder on axes notation in the CPV module:
377 // axis Z goes along the beam
378 // axis X goes across the beam in the module plane
379 // axis Y is a normal to the module plane showing from the IP
381 Float_t hitX = zxhit[0];
382 Float_t hitZ =-zxhit[1];
385 Float_t pNorm = p.Py();
386 Float_t eloss = kdEdx;
388 // cout << "CPVDigitize: YVK : "<<hitX<<" "<<hitZ<<" | "<<pX<<" "<<pZ<<" "<<pNorm<<endl;
390 Float_t dZY = pZ/pNorm * fGeom->GetCPVGasThickness();
391 Float_t dXY = pX/pNorm * fGeom->GetCPVGasThickness();
392 gRandom->Rannor(rnor1,rnor2);
393 eloss *= (1 + kDetR*rnor1) *
394 TMath::Sqrt((1 + ( pow(dZY,2) + pow(dXY,2) ) / pow(fGeom->GetCPVGasThickness(),2)));
395 Float_t zhit1 = hitZ + fGeom->GetCPVActiveSize(1)/2 - dZY/2;
396 Float_t xhit1 = hitX + fGeom->GetCPVActiveSize(0)/2 - dXY/2;
397 Float_t zhit2 = zhit1 + dZY;
398 Float_t xhit2 = xhit1 + dXY;
400 Int_t iwht1 = (Int_t) (xhit1 / kCelWr); // wire (x) coordinate "in"
401 Int_t iwht2 = (Int_t) (xhit2 / kCelWr); // wire (x) coordinate "out"
405 if (iwht1==iwht2) { // incline 1-wire hit
407 zxe[0][0] = (zhit1 + zhit2 - dZY*0.57735) / 2;
408 zxe[1][0] = (iwht1 + 0.5) * kCelWr;
410 zxe[0][1] = (zhit1 + zhit2 + dZY*0.57735) / 2;
411 zxe[1][1] = (iwht1 + 0.5) * kCelWr;
414 else if (TMath::Abs(iwht1-iwht2) != 1) { // incline 3-wire hit
416 Int_t iwht3 = (iwht1 + iwht2) / 2;
417 Float_t xwht1 = (iwht1 + 0.5) * kCelWr; // wire 1
418 Float_t xwht2 = (iwht2 + 0.5) * kCelWr; // wire 2
419 Float_t xwht3 = (iwht3 + 0.5) * kCelWr; // wire 3
420 Float_t xwr13 = (xwht1 + xwht3) / 2; // center 13
421 Float_t xwr23 = (xwht2 + xwht3) / 2; // center 23
422 Float_t dxw1 = xhit1 - xwr13;
423 Float_t dxw2 = xhit2 - xwr23;
424 Float_t egm1 = TMath::Abs(dxw1) / ( TMath::Abs(dxw1) + TMath::Abs(dxw2) + kCelWr );
425 Float_t egm2 = TMath::Abs(dxw2) / ( TMath::Abs(dxw1) + TMath::Abs(dxw2) + kCelWr );
426 Float_t egm3 = kCelWr / ( TMath::Abs(dxw1) + TMath::Abs(dxw2) + kCelWr );
427 zxe[0][0] = (dXY*(xwr13-xwht1)/dXY + zhit1 + zhit1) / 2;
429 zxe[2][0] = eloss * egm1;
430 zxe[0][1] = (dXY*(xwr23-xwht1)/dXY + zhit1 + zhit2) / 2;
432 zxe[2][1] = eloss * egm2;
433 zxe[0][2] = dXY*(xwht3-xwht1)/dXY + zhit1;
435 zxe[2][2] = eloss * egm3;
437 else { // incline 2-wire hit
439 Float_t xwht1 = (iwht1 + 0.5) * kCelWr;
440 Float_t xwht2 = (iwht2 + 0.5) * kCelWr;
441 Float_t xwr12 = (xwht1 + xwht2) / 2;
442 Float_t dxw1 = xhit1 - xwr12;
443 Float_t dxw2 = xhit2 - xwr12;
444 Float_t egm1 = TMath::Abs(dxw1) / ( TMath::Abs(dxw1) + TMath::Abs(dxw2) );
445 Float_t egm2 = TMath::Abs(dxw2) / ( TMath::Abs(dxw1) + TMath::Abs(dxw2) );
446 zxe[0][0] = (zhit1 + zhit2 - dZY*egm1) / 2;
448 zxe[2][0] = eloss * egm1;
449 zxe[0][1] = (zhit1 + zhit2 + dZY*egm2) / 2;
451 zxe[2][1] = eloss * egm2;
454 // Finite size of ionization region
456 Int_t nCellZ = fGeom->GetNumberOfCPVPadsZ();
457 Int_t nCellX = fGeom->GetNumberOfCPVPadsPhi();
458 Int_t nz3 = (kNgamz+1)/2;
459 Int_t nx3 = (kNgamx+1)/2;
460 cpvDigits->Expand(nIter*kNgamx*kNgamz);
461 TClonesArray &ldigits = *(TClonesArray *)cpvDigits;
463 for (Int_t iter=0; iter<nIter; iter++) {
465 Float_t zhit = zxe[0][iter];
466 Float_t xhit = zxe[1][iter];
467 Float_t qhit = zxe[2][iter];
468 Float_t zcell = zhit / fGeom->GetPadSizeZ();
469 Float_t xcell = xhit / fGeom->GetPadSizePhi();
470 if ( zcell<=0 || xcell<=0 ||
471 zcell>=nCellZ || xcell>=nCellX) return;
472 Int_t izcell = (Int_t) zcell;
473 Int_t ixcell = (Int_t) xcell;
474 Float_t zc = zcell - izcell - 0.5;
475 Float_t xc = xcell - ixcell - 0.5;
476 for (Int_t iz=1; iz<=kNgamz; iz++) {
477 Int_t kzg = izcell + iz - nz3;
478 if (kzg<=0 || kzg>nCellZ) continue;
479 Float_t zg = (Float_t)(iz-nz3) - zc;
480 for (Int_t ix=1; ix<=kNgamx; ix++) {
481 Int_t kxg = ixcell + ix - nx3;
482 if (kxg<=0 || kxg>nCellX) continue;
483 Float_t xg = (Float_t)(ix-nx3) - xc;
485 // Now calculate pad response
486 Float_t qpad = CPVPadResponseFunction(qhit,zg,xg);
487 qpad += kNoise*rnor2;
488 if (qpad<0) continue;
490 // Fill the array with pad response ID and amplitude
491 new(ldigits[cpvDigits->GetEntriesFast()]) AliPHOSCPVDigit(kxg,kzg,qpad);
497 //____________________________________________________________________________
498 Float_t AliPHOSv1::CPVPadResponseFunction(Float_t qhit, Float_t zhit, Float_t xhit) {
499 // ------------------------------------------------------------------------
500 // Calculate the amplitude in one CPV pad using the
501 // cumulative pad response function
502 // Author: Yuri Kharlov (after Serguei Sadovski)
504 // ------------------------------------------------------------------------
506 Double_t dz = fGeom->GetPadSizeZ() / 2;
507 Double_t dx = fGeom->GetPadSizePhi() / 2;
508 Double_t z = zhit * fGeom->GetPadSizeZ();
509 Double_t x = xhit * fGeom->GetPadSizePhi();
510 Double_t amplitude = qhit *
511 (CPVCumulPadResponse(z+dz,x+dx) - CPVCumulPadResponse(z+dz,x-dx) -
512 CPVCumulPadResponse(z-dz,x+dx) + CPVCumulPadResponse(z-dz,x-dx));
513 return (Float_t)amplitude;
516 //____________________________________________________________________________
517 Double_t AliPHOSv1::CPVCumulPadResponse(Double_t x, Double_t y) {
518 // ------------------------------------------------------------------------
519 // Cumulative pad response function
520 // It includes several terms from the CF decomposition in electrostatics
521 // Note: this cumulative function is wrong since omits some terms
522 // but the cell amplitude obtained with it is correct because
523 // these omitting terms cancel
524 // Author: Yuri Kharlov (after Serguei Sadovski)
526 // ------------------------------------------------------------------------
528 const Double_t kA=1.0;
529 const Double_t kB=0.7;
531 Double_t r2 = x*x + y*y;
533 Double_t cumulPRF = 0;
534 for (Int_t i=0; i<=4; i++) {
535 Double_t b1 = (2*i + 1) * kB;
536 cumulPRF += TMath::Power(-1,i) * TMath::ATan( xy / (b1*TMath::Sqrt(b1*b1 + r2)) );
538 cumulPRF *= kA/(2*TMath::Pi());