1 /**************************************************************************
2 * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
4 * Author: The ALICE Off-line Project. *
5 * Contributors are mentioned in the code where appropriate. *
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8 * documentation strictly for non-commercial purposes is hereby granted *
9 * without fee, provided that the above copyright notice appears in all *
10 * copies and that both the copyright notice and this permission notice *
11 * appear in the supporting documentation. The authors make no claims *
12 * about the suitability of this software for any purpose. It is *
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14 **************************************************************************/
18 //_________________________________________________________________________
19 // Implementation version v0 of PHOS Manager class
20 // Layout EMC + PPSD has name GPS2
21 // The main goal of this version of AliPHOS is to calculte the
22 // induced charged in the PIN diode, taking into account light
23 // tracking in the PbWO4 crystal, induced signal in the
24 // PIN due to MIPS particle and electronic noise.
25 // This is done in the StepManager
27 //*-- Author: Odd Harald Oddland & Gines Martinez (SUBATECH)
30 // --- ROOT system ---
33 // --- Standard library ---
38 #include <strstream.h>
40 // --- AliRoot header files ---
42 #include "AliPHOSv3.h"
43 #include "AliPHOSHit.h"
44 #include "AliPHOSDigit.h"
51 //____________________________________________________________________________
52 AliPHOSv3::AliPHOSv3(const char *name, const char *title):
57 // Number of electrons created in the PIN due to light collected in the PbWo4 crystal is calculated using
59 // NumberOfElectrons = EnergyLost * LightYield * PINEfficiency *
60 // exp (-LightYieldAttenuation * DistanceToPINdiodeFromTheHit) *
61 // RecalibrationFactor ;
62 // LightYield is obtained as a Poissonian distribution with a mean at 700000 photons per GeV fromValery Antonenko
63 // PINEfficiency is 0.1875 from Odd Harald Odland work
64 // k_0 is 0.0045 from Valery Antonenko
67 fLightYieldMean = 700000. ;
68 fIntrinsicPINEfficiency = 0.1875 ;
69 fLightYieldAttenuation = 0.0045 ;
70 fRecalibrationFactor = 6.2 / fLightYieldMean ;
71 fElectronsPerGeV = 2.77e+8 ;
74 //____________________________________________________________________________
75 AliPHOSv3::AliPHOSv3(AliPHOSReconstructioner * Reconstructioner, const char *name, const char *title):
76 AliPHOSv1(Reconstructioner,name,title)
80 // Number of electrons created in the PIN due to light collected in the PbWo4 crystal is calculated using
82 // NumberOfElectrons = EnergyLost * LightYield * PINEfficiency *
83 // exp (-LightYieldAttenuation * DistanceToPINdiodeFromTheHit) *
84 // RecalibrationFactor ;
85 // LightYield is obtained as a Poissonian distribution with a mean at 700000 photons per GeV fromValery Antonenko
86 // PINEfficiency is 0.1875 from Odd Harald Odland work
87 // k_0 is 0.0045 from Valery Antonenko
89 fLightYieldMean = 700000.;
90 fIntrinsicPINEfficiency = 0.1875 ;
91 fLightYieldAttenuation = 0.0045 ;
92 fRecalibrationFactor = 6.2 / fLightYieldMean ;
93 fElectronsPerGeV = 2.77e+8 ;
96 //____________________________________________________________________________
97 void AliPHOSv3::StepManager(void)
99 // Accumulates hits as long as the track stays in a single crystal or PPSD gas Cell
100 // Adds the energy deposited in the PIN diode
102 Int_t relid[4] ; // (box, layer, row, column) indices
103 Float_t xyze[4] ; // position wrt MRS and energy deposited
106 Float_t lightyield ; // Light Yield per GeV
107 Float_t nElectrons ; // Number of electrons in the PIN diode
108 TString name = fGeom->GetName() ;
113 Int_t tracknumber = gAlice->CurrentTrack() ;
114 Int_t primary = gAlice->GetPrimary( gAlice->CurrentTrack() );
116 if ( name == "GPS2" ) { // the CPV is a PPSD
117 if( gMC->CurrentVolID(copy) == gMC->VolId("GCEL") ) // We are inside a gas cell
119 gMC->TrackPosition(pos) ;
123 xyze[3] = gMC->Edep() ;
126 if ( xyze[3] != 0 ) { // there is deposited energy
127 gMC->CurrentVolOffID(5, relid[0]) ; // get the PHOS Module number
128 gMC->CurrentVolOffID(3, relid[1]) ; // get the Micromegas Module number
129 // 1-> Geom->GetNumberOfModulesPhi() * fGeom->GetNumberOfModulesZ() upper
130 // > fGeom->GetNumberOfModulesPhi() * fGeom->GetNumberOfModulesZ() lower
131 gMC->CurrentVolOffID(1, relid[2]) ; // get the row number of the cell
132 gMC->CurrentVolID(relid[3]) ; // get the column number
134 // get the absolute Id number
137 fGeom->RelToAbsNumbering(relid,absid) ;
140 AddHit(fIshunt, primary, tracknumber, absid, xyze);
142 } // there is deposited energy
143 } // We are inside the gas of the CPV
144 } // GPS2 configuration
146 if(gMC->CurrentVolID(copy) == gMC->VolId("PXTL") )// We are inside a PBWO crystal
148 gMC->TrackPosition(pos) ;
152 lostenergy = gMC->Edep() ;
153 xyze[3] = gMC->Edep() ;
159 if ( xyze[3] != 0 ) {
160 gMC->CurrentVolOffID(10, relid[0]) ; // get the PHOS module number ;
161 relid[1] = 0 ; // means PW04
162 gMC->CurrentVolOffID(4, relid[2]) ; // get the row number inside the module
163 gMC->CurrentVolOffID(3, relid[3]) ; // get the cell number inside the module
165 // get the absolute Id number
168 fGeom->RelToAbsNumbering(relid,absid) ;
169 gMC->Gmtod(global, local, 1) ;
171 // calculating number of electrons in the PIN diode asociated to this hit
172 lightyield = gRandom->Poisson(fLightYieldMean) ;
173 nElectrons = lostenergy * lightyield * fIntrinsicPINEfficiency *
174 exp(-fLightYieldAttenuation * (local[1]+fGeom->GetCrystalSize(1)/2.0 ) ) ;
176 xyze[3] = nElectrons * fRecalibrationFactor ;
177 // add current hit to the hit list
178 AddHit(fIshunt, primary, tracknumber, absid, xyze);
180 } // there is deposited energy
181 } // we are inside a PHOS Xtal
183 if(gMC->CurrentVolID(copy) == gMC->VolId("PPIN") ) // We are inside de PIN diode
185 gMC->TrackPosition(pos) ;
189 lostenergy = gMC->Edep() ;
190 xyze[3] = gMC->Edep() ;
192 if ( xyze[3] != 0 ) {
193 gMC->CurrentVolOffID(11, relid[0]) ; // get the PHOS module number ;
194 relid[1] = 0 ; // means PW04 and PIN
195 gMC->CurrentVolOffID(5, relid[2]) ; // get the row number inside the module
196 gMC->CurrentVolOffID(4, relid[3]) ; // get the cell number inside the module
198 // get the absolute Id number
201 fGeom->RelToAbsNumbering(relid,absid) ;
203 // calculating number of electrons in the PIN diode asociated to this hit
204 nElectrons = lostenergy * fElectronsPerGeV ;
205 xyze[3] = nElectrons * fRecalibrationFactor ;
207 // add current hit to the hit list
208 AddHit(fIshunt, primary, tracknumber, absid, xyze);
209 //printf("PIN volume is %d, %d, %d, %d \n",relid[0],relid[1],relid[2],relid[3]);
210 //printf("Lost energy in the PIN is %f \n",lostenergy) ;
211 } // there is deposited energy
212 } // we are inside a PHOS XtalPHOS PIN diode