[u/mrichter/AliRoot.git] / PHOS / AliPHOS.cxx

/**************************************************************************
 * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
 *                                                                        *
 * Author: The ALICE Off-line Project.                                    *
 * Contributors are mentioned in the code where appropriate.              *
 *                                                                        *
 * Permission to use, copy, modify and distribute this software and its   *
 * documentation strictly for non-commercial purposes is hereby granted   *
 * without fee, provided that the above copyright notice appears in all   *
 * copies and that both the copyright notice and this permission notice   *
 * appear in the supporting documentation. The authors make no claims     *
 * about the suitability of this software for any purpose. It is          *
 * provided "as is" without express or implied warranty.                  *
 **************************************************************************/
/* $Id$ */
/* History of cvs commits:
 *
 * $Log$
 * Revision 1.89  2005/05/28 12:10:07  schutz
 * Copy constructor is corrected (by T.P.)
 *
 */

//_________________________________________________________________________
// Base Class for PHOS description:
//   PHOS consists of a PbWO4 calorimeter (EMCA) and a gazeous charged 
//    particles detector (CPV or PPSD).
//   The only provided method here is CreateMaterials, 
//    which defines the materials common to all PHOS versions.   
// 
//*-- Author: Laurent Aphecetche & Yves Schutz (SUBATECH) 
//////////////////////////////////////////////////////////////////////////////


// --- ROOT system ---
class TFile;
#include <TFolder.h> 
#include <TTree.h>
#include <TVirtualMC.h> 
#include <TH1F.h> 
#include <TF1.h> 
#include <TRandom.h> 

// --- Standard library ---

// --- AliRoot header files ---
#include "AliMagF.h"
#include "AliPHOS.h"
#include "AliPHOSGetter.h"
#include "AliRun.h"
#include "AliPHOSDigitizer.h"
#include "AliPHOSSDigitizer.h"
#include "AliPHOSDigit.h"
#include "AliAltroBuffer.h"
#include "AliLog.h"

ClassImp(AliPHOS)

Double_t AliPHOS::fgCapa        = 1.;        // 1pF 
Int_t    AliPHOS::fgOrder       = 2 ;
Double_t AliPHOS::fgTimeMax     = 2.56E-5 ;  // each sample is over 100 ns fTimeMax/fTimeBins
Double_t AliPHOS::fgTimePeak    = 4.1E-6 ;   // 4 micro seconds
Double_t AliPHOS::fgTimeTrigger = 100E-9 ;      // 100ns, just for a reference

//____________________________________________________________________________
  AliPHOS:: AliPHOS() : AliDetector()
{
  // Default ctor
  fName   = "PHOS" ;

}

//____________________________________________________________________________
AliPHOS::AliPHOS(const char* name, const char* title): AliDetector(name, title)
{
  //   ctor : title is used to identify the layout
  
  fHighCharge        = 8.2 ;          // adjusted for a high gain range of 5.12 GeV (10 bits)
  fHighGain          = 6.64 ; 
  fHighLowGainFactor = 16. ;          // adjusted for a low gain range of 82 GeV (10 bits) 
  fLowGainOffset     = GetGeometry()->GetNModules() + 1 ;   
    // offset added to the module id to distinguish high and low gain data
}

//____________________________________________________________________________
AliPHOS::~AliPHOS() 
{  
}

//____________________________________________________________________________
void AliPHOS::Copy(TObject &obj)const
{
  // copy method to be used byy the cpy ctor
  TObject::Copy(obj);
  
  AliPHOS &phos = static_cast<AliPHOS &>(obj); 
  
  phos.fHighCharge        = fHighCharge ;
  phos.fHighGain          = fHighGain ; 
  phos.fHighLowGainFactor = fHighLowGainFactor ;  
  phos.fLowGainOffset     = fLowGainOffset;   
}

//____________________________________________________________________________
AliDigitizer* AliPHOS::CreateDigitizer(AliRunDigitizer* manager) const
{
  return new AliPHOSDigitizer(manager);
}

//____________________________________________________________________________
void AliPHOS::CreateMaterials()
{
  // Definitions of materials to build PHOS and associated tracking media.
  // media number in idtmed are 699 to 798.

  // --- The PbWO4 crystals ---
  Float_t aX[3] = {207.19, 183.85, 16.0} ;
  Float_t zX[3] = {82.0, 74.0, 8.0} ;
  Float_t wX[3] = {1.0, 1.0, 4.0} ;
  Float_t dX = 8.28 ;

  AliMixture(0, "PbWO4$", aX, zX, dX, -3, wX) ;


  // --- The polysterene scintillator (CH) ---
  Float_t aP[2] = {12.011, 1.00794} ;
  Float_t zP[2] = {6.0, 1.0} ;
  Float_t wP[2] = {1.0, 1.0} ;
  Float_t dP = 1.032 ;

  AliMixture(1, "Polystyrene$", aP, zP, dP, -2, wP) ;

  // --- Aluminium ---
  AliMaterial(2, "Al$", 26.98, 13., 2.7, 8.9, 999., 0, 0) ;
  // ---         Absorption length is ignored ^

 // --- Tyvek (CnH2n) ---
  Float_t aT[2] = {12.011, 1.00794} ;
  Float_t zT[2] = {6.0, 1.0} ;
  Float_t wT[2] = {1.0, 2.0} ;
  Float_t dT = 0.331 ;

  AliMixture(3, "Tyvek$", aT, zT, dT, -2, wT) ;

  // --- Polystyrene foam ---
  Float_t aF[2] = {12.011, 1.00794} ;
  Float_t zF[2] = {6.0, 1.0} ;
  Float_t wF[2] = {1.0, 1.0} ;
  Float_t dF = 0.12 ;

  AliMixture(4, "Foam$", aF, zF, dF, -2, wF) ;

 // --- Titanium ---
  Float_t aTIT[3] = {47.88, 26.98, 54.94} ;
  Float_t zTIT[3] = {22.0, 13.0, 25.0} ;
  Float_t wTIT[3] = {69.0, 6.0, 1.0} ;
  Float_t dTIT = 4.5 ;

  AliMixture(5, "Titanium$", aTIT, zTIT, dTIT, -3, wTIT);

 // --- Silicon ---
  AliMaterial(6, "Si$", 28.0855, 14., 2.33, 9.36, 42.3, 0, 0) ;


  // --- Foam thermo insulation ---
  Float_t aTI[2] = {12.011, 1.00794} ;
  Float_t zTI[2] = {6.0, 1.0} ;
  Float_t wTI[2] = {1.0, 1.0} ;
  Float_t dTI = 0.04 ;

  AliMixture(7, "Thermo Insul.$", aTI, zTI, dTI, -2, wTI) ;

  // --- Textolith ---
  Float_t aTX[4] = {16.0, 28.09, 12.011, 1.00794} ;
  Float_t zTX[4] = {8.0, 14.0, 6.0, 1.0} ;
  Float_t wTX[4] = {292.0, 68.0, 462.0, 736.0} ;
  Float_t dTX    = 1.75 ;

  AliMixture(8, "Textolit$", aTX, zTX, dTX, -4, wTX) ;

  //--- FR4  ---
  Float_t aFR[4] = {16.0, 28.09, 12.011, 1.00794} ;
  Float_t zFR[4] = {8.0, 14.0, 6.0, 1.0} ;
  Float_t wFR[4] = {292.0, 68.0, 462.0, 736.0} ;
  Float_t dFR = 1.8 ; 

  AliMixture(9, "FR4$", aFR, zFR, dFR, -4, wFR) ;

  // --- The Composite Material for  micromegas (so far polyetylene) ---                                       
  Float_t aCM[2] = {12.01, 1.} ; 
  Float_t zCM[2] = {6., 1.} ; 
  Float_t wCM[2] = {1., 2.} ; 
  Float_t dCM = 0.935 ; 

  AliMixture(10, "Compo Mat$", aCM, zCM, dCM, -2, wCM) ;

  // --- Copper ---                                                                    
  AliMaterial(11, "Cu$", 63.546, 29, 8.96, 1.43, 14.8, 0, 0) ;
 
  // --- G10 : Printed Circuit material ---                                                  
  Float_t aG10[4] = { 12., 1., 16., 28.} ;
  Float_t zG10[4] = { 6., 1., 8., 14.} ;
  Float_t wG10[4] = { .259, .288, .248, .205} ;
  Float_t dG10  = 1.7 ;
  
  AliMixture(12, "G10$", aG10, zG10, dG10, -4, wG10);

  // --- Lead ---                                                                     
  AliMaterial(13, "Pb$", 207.2, 82, 11.35, 0.56, 0., 0, 0) ;

 // --- The gas mixture ---                                                                
 // Co2
  Float_t aCO[2] = {12.0, 16.0} ; 
  Float_t zCO[2] = {6.0, 8.0} ; 
  Float_t wCO[2] = {1.0, 2.0} ; 
  Float_t dCO = 0.001977 ; 

  AliMixture(14, "CO2$", aCO, zCO, dCO, -2, wCO);

 // Ar
  Float_t dAr = 0.001782 ; 
  AliMaterial(15, "Ar$", 39.948, 18.0, dAr, 14.0, 0., 0, 0) ;   
 
 // ArCo2
  Char_t namate[21]="";
  Float_t aGM[2] ; 
  Float_t zGM[2] ; 
  Float_t wGM[2] ; 
  Float_t dGM ; 

  Float_t absL, radL, density ;
  Float_t buf[1] ;
  Int_t nbuf ;

  gMC->Gfmate((*fIdmate)[15], namate, aGM[0], zGM[0], density, radL, absL, buf, nbuf) ; // Get properties of Ar 
  gMC->Gfmate((*fIdmate)[14], namate, aGM[1], zGM[1], density, radL, absL, buf, nbuf) ; // Get properties of CO2 


  // Create gas mixture 

  Float_t arContent    = 0.80 ;  // Ar-content of the Ar/CO2-mixture (80% / 20%) 
 
  wGM[0] = arContent;
  wGM[1] = 1. - arContent ;
  dGM    = wGM[0] * dAr + wGM[1] * dCO;

  
  AliMixture(16, "ArCO2$", aGM, zGM, dGM,  2, wGM) ;

  // --- Stainless steel (let it be pure iron) ---
  AliMaterial(17, "Steel$", 55.845, 26, 7.87, 1.76, 0., 0, 0) ;


  // --- Fiberglass ---
  Float_t aFG[4] = {16.0, 28.09, 12.011, 1.00794} ;
  Float_t zFG[4] = {8.0, 14.0, 6.0, 1.0} ;
  Float_t wFG[4] = {292.0, 68.0, 462.0, 736.0} ;
  Float_t dFG    = 1.9 ;

  AliMixture(18, "Fibergla$", aFG, zFG, dFG, -4, wFG) ;

  // --- Cables in Air box  ---
  // SERVICES

  Float_t aCA[4] = { 1.,12.,55.8,63.5 };
  Float_t zCA[4] = { 1.,6.,26.,29. }; 
  Float_t wCA[4] = { .014,.086,.42,.48 };
  Float_t dCA    = 0.8 ;  //this density is raw estimation, if you know better - correct

  AliMixture(19, "Cables  $", aCA, zCA, dCA, -4, wCA) ;


  // --- Air ---
  Float_t aAir[4]={12.0107,14.0067,15.9994,39.948};
  Float_t zAir[4]={6.,7.,8.,18.};
  Float_t wAir[4]={0.000124,0.755267,0.231781,0.012827};
  Float_t dAir = 1.20479E-3;
 
  AliMixture(99, "Air$", aAir, zAir, dAir, 4, wAir) ;

  // DEFINITION OF THE TRACKING MEDIA

  // for PHOS: idtmed[699->798] equivalent to fIdtmed[0->100]
  Int_t * idtmed = fIdtmed->GetArray() - 699 ; 
  Int_t   isxfld = gAlice->Field()->Integ() ;
  Float_t sxmgmx = gAlice->Field()->Max() ;

  // The scintillator of the calorimeter made of PBW04                              -> idtmed[699]
  AliMedium(0, "PHOS Xtal    $", 0, 1,
	    isxfld, sxmgmx, 10.0, 0.1, 0.1, 0.1, 0.1, 0, 0) ;

  // The scintillator of the CPV made of Polystyrene scintillator                   -> idtmed[700]
  AliMedium(1, "CPV scint.   $", 1, 1,
	    isxfld, sxmgmx, 10.0, 0.1, 0.1, 0.1, 0.1, 0, 0) ;

  // Various Aluminium parts made of Al                                             -> idtmed[701]
  AliMedium(2, "Al parts     $", 2, 0,
	     isxfld, sxmgmx, 10.0, 0.1, 0.1, 0.001, 0.001, 0, 0) ;

  // The Tywek which wraps the calorimeter crystals                                 -> idtmed[702]
  AliMedium(3, "Tyvek wrapper$", 3, 0,
	     isxfld, sxmgmx, 10.0, 0.1, 0.1, 0.001, 0.001, 0, 0) ;

  // The Polystyrene foam around the calorimeter module                             -> idtmed[703]
  AliMedium(4, "Polyst. foam $", 4, 0,
	     isxfld, sxmgmx, 10.0, 0.1, 0.1, 0.1, 0.1, 0, 0) ;

  // The Titanium around the calorimeter crystal                                    -> idtmed[704]
  AliMedium(5, "Titan. cover $", 5, 0,
	     isxfld, sxmgmx, 10.0, 0.1, 0.1, 0.0001, 0.0001, 0, 0) ;

  // The Silicon of the pin diode to read out the calorimeter crystal               -> idtmed[705] 
 AliMedium(6, "Si PIN       $", 6, 0,
	     isxfld, sxmgmx, 10.0, 0.1, 0.1, 0.01, 0.01, 0, 0) ;

 // The thermo insulating material of the box which contains the calorimeter module -> idtmed[706]
  AliMedium(7, "Thermo Insul.$", 7, 0,
	     isxfld, sxmgmx, 10.0, 0.1, 0.1, 0.1, 0.1, 0, 0) ;

  // The Textolit which makes up the box which contains the calorimeter module      -> idtmed[707]
  AliMedium(8, "Textolit     $", 8, 0,
	     isxfld, sxmgmx, 10.0, 0.1, 0.1, 0.1, 0.1, 0, 0) ;

  // FR4: The Plastic which makes up the frame of micromegas                        -> idtmed[708]
  AliMedium(9, "FR4 $", 9, 0,
	     isxfld, sxmgmx, 10.0, 0.1, 0.1, 0.1, 0.0001, 0, 0) ; 


  // The Composite Material for  micromegas                                         -> idtmed[709]
  AliMedium(10, "CompoMat   $", 10, 0,
	     isxfld, sxmgmx, 10.0, 0.1, 0.1, 0.1, 0.1, 0, 0) ;

  // Copper                                                                         -> idtmed[710]
  AliMedium(11, "Copper     $", 11, 0,
	     isxfld, sxmgmx, 10.0, 0.1, 0.1, 0.1, 0.0001, 0, 0) ;

  // G10: Printed Circuit material                                                  -> idtmed[711]
 
  AliMedium(12, "G10        $", 12, 0,
	     isxfld, sxmgmx, 10.0, 0.1, 0.1, 0.1, 0.01, 0, 0) ;

  // The Lead                                                                       -> idtmed[712]
 
  AliMedium(13, "Lead      $", 13, 0,
	     isxfld, sxmgmx, 10.0, 0.1, 0.1, 0.1, 0.1, 0, 0) ;

  // The gas mixture: ArCo2                                                         -> idtmed[715]
 
  AliMedium(16, "ArCo2      $", 16, 1,
	     isxfld, sxmgmx, 10.0, 0.1, 0.1, 0.1, 0.01, 0, 0) ;
 
  // Stainless steel                                                                -> idtmed[716]
  AliMedium(17, "Steel     $", 17, 0,
	     isxfld, sxmgmx, 10.0, 0.1, 0.1, 0.1, 0.0001, 0, 0) ;

  // Fibergalss                                                                     -> idtmed[717]
  AliMedium(18, "Fiberglass$", 18, 0,
	     isxfld, sxmgmx, 10.0, 0.1, 0.1, 0.1, 0.1, 0, 0) ;

  // Cables in air                                                                  -> idtmed[718]
  AliMedium(19, "Cables    $", 19, 0,
	     isxfld, sxmgmx, 10.0, 0.1, 0.1, 0.1, 0.1, 0, 0) ;

  // Air                                                                            -> idtmed[798] 
  AliMedium(99, "Air          $", 99, 0,
	     isxfld, sxmgmx, 10.0, 1.0, 0.1, 0.1, 10.0, 0, 0) ;

  // --- Set decent energy thresholds for gamma and electron tracking

  // Tracking threshold for photons and electrons in the scintillator crystal 
  gMC->Gstpar(idtmed[699], "CUTGAM",0.5E-4) ; 
  gMC->Gstpar(idtmed[699], "CUTELE",1.0E-4) ;
 
  // --- Generate explicitly delta rays in the titan cover ---
  gMC->Gstpar(idtmed[704], "LOSS",3.) ;
  gMC->Gstpar(idtmed[704], "DRAY",1.) ;
  // --- and in aluminium parts ---
  gMC->Gstpar(idtmed[701], "LOSS",3.) ;
  gMC->Gstpar(idtmed[701], "DRAY",1.) ;
  // --- and in PIN diode
  gMC->Gstpar(idtmed[705], "LOSS",3) ;
  gMC->Gstpar(idtmed[705], "DRAY",1) ;
  // --- and in the passive convertor
  gMC->Gstpar(idtmed[712], "LOSS",3) ;
  gMC->Gstpar(idtmed[712], "DRAY",1) ;
  // Tracking threshold for photons and electrons in the gas ArC02 
  gMC->Gstpar(idtmed[715], "CUTGAM",1.E-5) ; 
  gMC->Gstpar(idtmed[715], "CUTELE",1.E-5) ;
  gMC->Gstpar(idtmed[715], "CUTNEU",1.E-5) ;
  gMC->Gstpar(idtmed[715], "CUTHAD",1.E-5) ;
  gMC->Gstpar(idtmed[715], "CUTMUO",1.E-5) ;
  gMC->Gstpar(idtmed[715], "BCUTE",1.E-5) ;
  gMC->Gstpar(idtmed[715], "BCUTM",1.E-5) ;
  gMC->Gstpar(idtmed[715], "DCUTE",1.E-5) ;
  gMC->Gstpar(idtmed[715], "DCUTM",1.E-5) ;
  gMC->Gstpar(idtmed[715], "PPCUTM",1.E-5) ;
  gMC->Gstpar(idtmed[715], "LOSS",2.) ;
  gMC->Gstpar(idtmed[715], "DRAY",0.) ;
  gMC->Gstpar(idtmed[715], "STRA",2.) ;

}

//____________________________________________________________________________
void AliPHOS::Digits2Raw()
{
// convert digits of the current event to raw data
  
  AliPHOSLoader * loader = dynamic_cast<AliPHOSLoader*>(fLoader) ; 

  // get the digits
  loader->LoadDigits();
  TClonesArray* digits = loader->Digits() ;

  if (!digits) {
    AliError(Form("No digits found !"));
    return;
  }

  // get the digitizer 
  loader->LoadDigitizer();
  AliPHOSDigitizer * digitizer = dynamic_cast<AliPHOSDigitizer *>(loader->Digitizer())  ; 
  
  // get the geometry
  AliPHOSGeometry* geom = GetGeometry();
  if (!geom) {
    AliError(Form("No geometry found !"));
    return;
  }

  // some digitization constants
  const Int_t    kDDLOffset = 0x600; // assigned to PHOS
  const Int_t    kThreshold = 1; // skip digits below this threshold

  AliAltroBuffer* buffer = NULL;
  Int_t prevDDL = -1;
  Int_t adcValuesLow[fkTimeBins];
  Int_t adcValuesHigh[fkTimeBins];

  // loop over digits (assume ordered digits)
  for (Int_t iDigit = 0; iDigit < digits->GetEntries(); iDigit++) {
    AliPHOSDigit* digit = dynamic_cast<AliPHOSDigit *>(digits->At(iDigit)) ;
    if (digit->GetAmp() < kThreshold) 
      continue;
    Int_t relId[4];
    geom->AbsToRelNumbering(digit->GetId(), relId);
    Int_t module = relId[0];
 
   // Begin FIXME 
    if (relId[1] != 0) 
      continue;    // ignore digits from CPV
   // End FIXME 

    // PHOS EMCA has 4 DDL per module. Splitting is done based on the row number
    Int_t iDDL = 4 * (module - 1) + (4 * (relId[2] - 1)) / geom->GetNPhi();

    // new DDL
    if (iDDL != prevDDL) {
      // write real header and close previous file
      if (buffer) {
	buffer->Flush();
	buffer->WriteDataHeader(kFALSE, kFALSE);
	delete buffer;
      }

      // open new file and write dummy header
      TString fileName("PHOS_") ;
      fileName += (iDDL + kDDLOffset) ; 
      fileName += ".ddl" ; 
      buffer = new AliAltroBuffer(fileName.Data(), 1);
      buffer->WriteDataHeader(kTRUE, kFALSE);  //Dummy;

      prevDDL = iDDL;
    }

    // out of time range signal (?)
    if (digit->GetTimeR() > GetRawFormatTimeMax() ) {
      buffer->FillBuffer(digit->GetAmp());
      buffer->FillBuffer(GetRawFormatTimeBins() );  // time bin
      buffer->FillBuffer(3);          // bunch length      
      buffer->WriteTrailer(3, relId[3], relId[2], module);  // trailer
      
    // calculate the time response function
    } else {
      Double_t energy = 0 ;  
      if ( digit->GetId() <= geom->GetNModules() *  geom->GetNCristalsInModule())
	energy = digit->GetAmp() * digitizer->GetEMCchannel() + digitizer->GetEMCpedestal() ; 
      else 
	energy = digit->GetAmp() * digitizer->GetCPVchannel() + digitizer->GetCPVpedestal() ;
        
      Bool_t lowgain = RawSampledResponse(digit->GetTimeR(), energy, adcValuesHigh, adcValuesLow) ; 
      
     if (lowgain) 
	buffer->WriteChannel(relId[3], relId[2], module + fLowGainOffset, 
			   GetRawFormatTimeBins(), adcValuesLow, kThreshold);
      else 
	buffer->WriteChannel(relId[3], relId[2], module, 
			     GetRawFormatTimeBins(), adcValuesHigh, kThreshold);
      
    }
  }
  
  // write real header and close last file
  if (buffer) {
    buffer->Flush();
    buffer->WriteDataHeader(kFALSE, kFALSE);
    delete buffer;
  }
  
  loader->UnloadDigits();
}

//____________________________________________________________________________
void AliPHOS::Hits2SDigits()  
{ 
// create summable digits

  AliPHOSSDigitizer phosDigitizer(fLoader->GetRunLoader()->GetFileName().Data()) ;
  phosDigitizer.SetEventRange(0, -1) ; // do all the events
  phosDigitizer.ExecuteTask("all") ; 
}

//____________________________________________________________________________
AliLoader* AliPHOS::MakeLoader(const char* topfoldername)
{
//different behaviour than standard (singleton getter)
// --> to be discussed and made eventually coherent
 fLoader = new AliPHOSLoader(GetName(),topfoldername);
 return fLoader;
}

//__________________________________________________________________
Double_t AliPHOS::RawResponseFunction(Double_t *x, Double_t *par) 
{
  // Shape of the electronics raw reponse:
  // It is a semi-gaussian, 2nd order Gamma function of the general form
  // v(t) = n**n * Q * A**n / C *(t/tp)**n * exp(-n * t/tp) with 
  // tp : peaking time par[0]
  // n  : order of the function
  // C  : integrating capacitor in the preamplifier
  // A  : open loop gain of the preamplifier
  // Q  : the total APD charge to be measured Q = C * energy
  
  Double_t signal ;
  Double_t xx = x[0] - ( fgTimeTrigger + par[3] ) ; 

  if (xx < 0 || xx > fgTimeMax) 
    signal = 0. ;  
  else { 
    Double_t fac = par[0] * TMath::Power(fgOrder, fgOrder) * TMath::Power(par[1], fgOrder) / fgCapa ; 
    signal = fac * par[2] * TMath::Power(xx / fgTimePeak, fgOrder) * TMath::Exp(-fgOrder * (xx / fgTimePeak)) ; 
  }
  return signal ;  
}

//__________________________________________________________________
Double_t AliPHOS::RawResponseFunctionMax(Double_t charge, Double_t gain) 
{
  return ( charge * TMath::Power(fgOrder, fgOrder) * TMath::Power(gain, fgOrder) 
     / ( fgCapa * TMath::Exp(fgOrder) ) );  

}

//__________________________________________________________________
Bool_t AliPHOS::RawSampledResponse(const Double_t dtime, const Double_t damp, Int_t * adcH, Int_t * adcL) const 
{
  // for a start time dtime and an amplitude damp given by digit, 
  // calculates the raw sampled response AliPHOS::RawResponseFunction

  const Int_t kRawSignalOverflow = 0x3FF ; 
  Bool_t lowGain = kFALSE ; 

  TF1 signalF("signal", RawResponseFunction, 0, GetRawFormatTimeMax(), 4);

  for (Int_t iTime = 0; iTime < GetRawFormatTimeBins(); iTime++) {
    signalF.SetParameter(0, GetRawFormatHighCharge() ) ; 
    signalF.SetParameter(1, GetRawFormatHighGain() ) ; 
    signalF.SetParameter(2, damp) ; 
    signalF.SetParameter(3, dtime) ; 
    Double_t time = iTime * GetRawFormatTimeMax() / GetRawFormatTimeBins() ;
    Double_t signal = signalF.Eval(time) ;     
    if ( static_cast<Int_t>(signal+0.5) > kRawSignalOverflow ){  // larger than 10 bits 
      signal = kRawSignalOverflow ;
      lowGain = kTRUE ; 
    }
    adcH[iTime] =  static_cast<Int_t>(signal + 0.5) ;

    signalF.SetParameter(0, GetRawFormatLowCharge() ) ;     
    signalF.SetParameter(1, GetRawFormatLowGain() ) ; 
    signal = signalF.Eval(time) ;  
    if ( static_cast<Int_t>(signal+0.5) > kRawSignalOverflow)  // larger than 10 bits 
      signal = kRawSignalOverflow ;
    adcL[iTime] = static_cast<Int_t>(0.5 + signal ) ; 

  }
  return lowGain ; 
}

//____________________________________________________________________________
void AliPHOS::SetTreeAddress()
{ 
  // Links Hits in the Tree to Hits array
  TBranch *branch;
  char branchname[20];
  sprintf(branchname,"%s",GetName());
  // Branch address for hit tree
    TTree *treeH = TreeH();
  if (treeH) {
    branch = treeH->GetBranch(branchname);
    if (branch) 
     { 
       if (fHits == 0x0) fHits= new TClonesArray("AliPHOSHit",1000);
       //AliInfo(Form("<%s> Setting Hits Address",GetName()));
       branch->SetAddress(&fHits);
     }
  }
}