RICH/AliRICHParam.cxx

   1 /**************************************************************************
   2  * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
   3  *                                                                        *
   4  * Author: The ALICE Off-line Project.                                    *
   5  * Contributors are mentioned in the code where appropriate.              *
   6  *                                                                        *
   7  * Permission to use, copy, modify and distribute this software and its   *
   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          *
  13  * provided "as is" without express or implied warranty.                  *
  14  **************************************************************************/
  15
  16 #include <Riostream.h>
  17 #include <TMath.h>
  18 #include <TRandom.h>
  19
  20 #include "AliRICHParam.h"
  21
  22 ClassImp(AliRICHParam)
  23
  24 // RICH main parameters manipulator
  25 //__________________________________________________________________________________________________
  26 AliRICHParam::AliRICHParam():
  27 fCurrentPadX(0),fCurrentPadY(0),fCurrentWire(0),
  28 fSizeZ(0),
  29 fAngleRot(0),fAngleYZ(0),fAngleXY(0),
  30 fOffset(0),
  31 fProximityGapThickness(0),
  32 fQuartzLength(0),
  33 fQuartzWidth(0),
  34 fOuterFreonLength(0),
  35 fOuterFreonWidth(0),
  36 fInnerFreonLength(0),
  37 fInnerFreonWidth(0),
  38 fChargeSlope(0),
  39 fChargeSpreadX(0),
  40 fChargeSpreadY(0),
  41 fSigmaIntegration(0),
  42 fAlphaFeedback(0),
  43 fEIonisation(0),
  44 fMaxAdc(0),
  45 fWireSag(0),
  46 fVoltage(0)
  47 {//defines the default parameters
  48   Size                 (132.6*kcm,26*kcm,136.7*kcm);  //full length, not GEANT half notation
  49   AngleRot             (-60);                         //rotation of the whole RICH around Z, deg
  50   Angles               (20,19.5);                     //XY angle, YZ angle  deg
  51   Offset               (490*kcm+1.267*kcm);           //1.267???????cm distance from IP to the center of module
  52   ProximityGapThickness(0.4*kcm);
  53   QuartzLength         (133*kcm);
  54   QuartzWidth          (127.9*kcm);
  55   OuterFreonLength     (133*kcm);
  56   OuterFreonWidth      (41.3*kcm);
  57   InnerFreonLength     (133*kcm);
  58   InnerFreonWidth      (41.3*kcm);
  59
  60   ChargeSlope(27.);
  61   ChargeSpreadX(0.18);ChargeSpreadY(0.18);
  62   SigmaIntegration(5.);
  63   MaxAdc(4096);
  64   AlphaFeedback(0.036);
  65   EIonisation(26.e-9);
  66   WireSag(1);                 // 1->On, 0->Off
  67   Voltage(2150);              // Should only be 2000, 2050, 2100 or 2150
  68 }//AliRICHParam::named ctor
  69 //__________________________________________________________________________________________________
  70 Int_t AliRICHParam::Local2Sector(Float_t &x, Float_t &y)
  71 {//Determines sector for a given hit (x,y) and trasform this point to the local system of that sector.
  72   Int_t sector=kBad;
  73   Float_t x1=-0.5*PcSizeX();      Float_t x2=-0.5*SectorSizeX()-DeadZone();  Float_t x3=-0.5*SectorSizeX();
  74   Float_t x4= 0.5*SectorSizeX();  Float_t x5= 0.5*SectorSizeX()+DeadZone();  Float_t x6= 0.5*PcSizeX();
  75
  76   if     (x>=x1&&x<=x2)    {sector=1;x+=0.5*PcSizeX();}
  77   else if(x>=x3&&x<=x4)    {sector=2;x+=0.5*SectorSizeX();}
  78   else if(x>=x5&&x<=x6)    {sector=3;x-=0.5*SectorSizeX()+DeadZone();}
  79   else if(x< x1||x> x6)    {return kBad;}
  80   else                                                        {return kBad;} //in dead zone
  81
  82   if     (y>=-0.5*PcSizeY()   &&y<=-0.5*DeadZone())  {y+=0.5*PcSizeY();  return -sector;}
  83   else if(y> -0.5*DeadZone()  &&y<  0.5*DeadZone())  {return kBad;} //in dead zone
  84   else if(y>= 0.5*DeadZone()  &&y<= 0.5*PcSizeY())   {y-=0.5*DeadZone(); return  sector;}
  85   else                                               {return kBad;}
  86 }//Int_t AliRICHParam::Local2Sector(Float_t x, Float_t y)
  87 //__________________________________________________________________________________________________
  88 Int_t AliRICHParam::Pad2Sector(Int_t &padx, Int_t &pady)
  89 {//Determines sector for a given pad (padx,pady) and trasform this point to the local system of that sector.
  90   Int_t sector=kBad;
  91   if     (padx>=1            &&padx<=NpadsXsec())      {sector=1;}
  92   else if(padx> NpadsXsec()  &&padx<=NpadsXsec()*2)    {sector=2;padx-=NpadsXsec();}
  93   else if(padx> NpadsXsec()*2&&padx<=NpadsX())         {sector=3;padx-=NpadsXsec()*2;}
  94   else                                                 {return kBad;}
  95
  96   if     (pady>=1         &&pady<= NpadsYsec())     {return -sector;}
  97   else if(pady>NpadsYsec()&&pady<= NpadsY())        {pady-=NpadsYsec();return sector;}
  98   else                                              {return kBad;}
  99 }//Local2Sector()
 100 //__________________________________________________________________________________________________
 101 Int_t AliRICHParam::Local2Pad(Float_t x, Float_t y, Int_t &padx, Int_t &pady)
 102 {//returns pad numbers (iPadX,iPadY) for given point in local coordinates (x,y)
 103  //count starts in lower left corner from 1,1 to 144,180
 104
 105   padx=pady=kBad;
 106   Int_t sector=Local2Sector(x,y);
 107   if(sector==kBad) return sector;
 108
 109   padx=Int_t(x/PadSizeX())+1;
 110   if(padx>NpadsXsec())            padx= NpadsXsec();
 111   if(sector==2||sector==-2)       padx+=NpadsXsec();
 112   else if(sector==3||sector==-3)  padx+=NpadsXsec()*2;
 113
 114   pady=Int_t(y/PadSizeY())+1;
 115   if(pady>NpadsYsec())            padx= NpadsYsec();
 116   if(sector>0)                    pady+=NpadsYsec();
 117
 118   return sector;
 119 }//Local2Pad()
 120 //__________________________________________________________________________________________________
 121 void AliRICHParam::Pad2Local(Int_t padx,Int_t pady,Float_t &x,Float_t &y)
 122 {
 123   Int_t sector=Pad2Sector(padx,pady);
 124   if(sector>0)
 125     y=0.5*DeadZone()+pady*PadSizeY()-0.5*PadSizeY();
 126   else{
 127     sector=-sector;
 128     y=-0.5*PcSizeY()+pady*PadSizeY()-0.5*PadSizeY();
 129   }
 130   if(sector==1)
 131     x=-0.5*PcSizeX()+padx*PadSizeX()-0.5*PadSizeX();
 132   else if(sector==2)
 133     x=-0.5*SectorSizeX()+padx*PadSizeX()-0.5*PadSizeX();
 134   else
 135     x= 0.5*SectorSizeX()+DeadZone()+padx*PadSizeX()-0.5*PadSizeX();
 136   return;
 137 }//Pad2Local()
 138 //__________________________________________________________________________________________________
 139 Float_t AliRICHParam::Gain(Float_t y)
 140 {//Calculates the gain
 141   if(fWireSag){
 142     Float_t gainK=9e-6*TMath::Power(y,4)+2e-7*TMath::Power(y,3)-0.0316*TMath::Power(y,2)-3e-4*y+25.367;
 143     Float_t gain = (ChargeSlope()+ChargeSlope()*gainK/100)*0.9;
 144     return -gain*TMath::Log(gRandom->Rndm());
 145   }else
 146     return -ChargeSlope()*TMath::Log(gRandom->Rndm());
 147 }//Float_t AliRICHParam::IntPH(Float_t yhit)
 148 //__________________________________________________________________________________________________
 149 Float_t AliRICHParam::TotalCharge(Int_t iPID,Float_t eloss,Float_t y)
 150 {//Get number of electrons and return charge
 151
 152   if(iPID>50000)//it's photon no more then 1 electron after photoelectron conversion
 153     return Gain(y);
 154   else{
 155     Int_t iNelectrons=Int_t(eloss/fEIonisation);if(iNelectrons==0) iNelectrons=1;
 156     Float_t charge=0;
 157     for(Int_t i=1;i<=iNelectrons;i++)
 158       charge+=Gain(y);
 159     return charge;
 160   }
 161 }//Float_t AliRICHParam::TotalCharge(Int_t iPID,Float_t eloss, Float_t y)
 162 //__________________________________________________________________________________________________
 163 void AliRICHParam::FirstPad(Float_t x,Float_t y)
 164 {
 165   Int_t padx,pady;
 166   Local2Pad(x,y,padx,pady);
 167 }//void AliRICHParam::FirstPad(Float_t x,Float_t y)
 168 //__________________________________________________________________________________________________
 169 Float_t AliRICHParam::AssignChargeToPad(Float_t hitx,Float_t hity,Int_t padx,Int_t pady)
 170 {//
 171   Float_t padXcenter=0,padYcenter=0;
 172   Pad2Local(padx,pady,padXcenter,padYcenter);
 173
 174   Float_t xi1=hitx-padXcenter-PadSizeX()/2;
 175   Float_t xi2=hitx-padXcenter+PadSizeX()/2;
 176   Float_t yi1=hity-padYcenter-PadSizeY()/2;
 177   Float_t yi2=hity-padYcenter+PadSizeY()/2;
 178   xi1/=AnodeCathodeGap();
 179   xi2/=AnodeCathodeGap();
 180   yi1/=AnodeCathodeGap();
 181   yi2/=AnodeCathodeGap();
 182 // The Mathieson function
 183   Double_t ux1=SqrtKx3()*TMath::TanH(Kx2()*xi1);
 184   Double_t ux2=SqrtKx3()*TMath::TanH(Kx2()*xi2);
 185   Double_t uy1=SqrtKy3()*TMath::TanH(Ky2()*yi1);
 186   Double_t uy2=SqrtKy3()*TMath::TanH(Ky2()*yi2);
 187   return 4.*Kx4()*(TMath::ATan(ux2)-TMath::ATan(ux1))*Ky4()*(TMath::ATan(uy2)-TMath::ATan(uy1));
 188 }//AssignChargeToPad()
 189 //__________________________________________________________________________________________________