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 fGapThickness(0),
  32 fProximityGapThickness(0),
  33 fQuartzLength(0),
  34 fQuartzWidth(0),
  35 fQuartzThickness(0),
  36 fOuterFreonLength(0),
  37 fOuterFreonWidth(0),
  38 fInnerFreonLength(0),
  39 fInnerFreonWidth(0),
  40 fFreonThickness(0),
  41 fRadiatorToPads(0),
  42 fChargeSlope(0),
  43 fChargeSpreadX(0),
  44 fChargeSpreadY(0),
  45 fSigmaIntegration(0),
  46 fAlphaFeedback(0),
  47 fEIonisation(0),
  48 fMaxAdc(0),
  49 fWireSag(0),
  50 fVoltage(0)
  51 {//defines the default parameters
  52   Size                 (132.6*kcm,26*kcm,136.7*kcm);  //full length, not GEANT half notation
  53   AngleRot             (-60);                         //rotation of the whole RICH around Z, deg
  54   Angles               (20,19.5);                     //XY angle, YZ angle  deg
  55   Offset               (490*kcm+1.267*kcm);           //1.267???????cm distance from IP to the center of module
  56   GapThickness         (8*kcm);
  57   ProximityGapThickness(0.4*kcm);
  58   QuartzLength         (133*kcm);
  59   QuartzWidth          (127.9*kcm);
  60   QuartzThickness      (0.5*kcm);
  61   OuterFreonLength     (133*kcm);
  62   OuterFreonWidth      (41.3*kcm);
  63   InnerFreonLength     (133*kcm);
  64   InnerFreonWidth      (41.3*kcm);
  65   FreonThickness       (1.5*kcm);
  66   RadiatorToPads       (80*kmm);
  67
  68   ChargeSlope(27.);
  69   ChargeSpreadX(0.18);ChargeSpreadY(0.18);
  70   SigmaIntegration(5.);
  71   MaxAdc(4096);
  72   AlphaFeedback(0.036);
  73   EIonisation(26.e-9);
  74   WireSag(1);                 // 1->On, 0->Off
  75   Voltage(2150);              // Should only be 2000, 2050, 2100 or 2150
  76 }//AliRICHParam::named ctor
  77 //__________________________________________________________________________________________________
  78 Int_t AliRICHParam::Local2Sector(Float_t &x, Float_t &y)
  79 {//Determines sector for a given hit (x,y) and trasform this point to the local system of that sector.
  80   Int_t sector=kBad;
  81   Float_t x1=-0.5*PcSizeX();      Float_t x2=-0.5*SectorSizeX()-DeadZone();  Float_t x3=-0.5*SectorSizeX();
  82   Float_t x4= 0.5*SectorSizeX();  Float_t x5= 0.5*SectorSizeX()+DeadZone();  Float_t x6= 0.5*PcSizeX();
  83
  84   if     (x>=x1&&x<=x2)    {sector=1;x+=0.5*PcSizeX();}
  85   else if(x>=x3&&x<=x4)    {sector=2;x+=0.5*SectorSizeX();}
  86   else if(x>=x5&&x<=x6)    {sector=3;x-=0.5*SectorSizeX()+DeadZone();}
  87   else if(x< x1||x> x6)    {return kBad;}
  88   else                                                        {return kBad;} //in dead zone
  89
  90   if     (y>=-0.5*PcSizeY()   &&y<=-0.5*DeadZone())  {y+=0.5*PcSizeY();  return -sector;}
  91   else if(y> -0.5*DeadZone()  &&y<  0.5*DeadZone())  {return kBad;} //in dead zone
  92   else if(y>= 0.5*DeadZone()  &&y<= 0.5*PcSizeY())   {y-=0.5*DeadZone(); return  sector;}
  93   else                                               {return kBad;}
  94 }//Int_t AliRICHParam::Local2Sector(Float_t x, Float_t y)
  95 //__________________________________________________________________________________________________
  96 Int_t AliRICHParam::Pad2Sector(Int_t &padx, Int_t &pady)
  97 {//Determines sector for a given pad (padx,pady) and trasform this point to the local system of that sector.
  98   Int_t sector=kBad;
  99   if     (padx>=1            &&padx<=NpadsXsec())      {sector=1;}
 100   else if(padx> NpadsXsec()  &&padx<=NpadsXsec()*2)    {sector=2;padx-=NpadsXsec();}
 101   else if(padx> NpadsXsec()*2&&padx<=NpadsX())         {sector=3;padx-=NpadsXsec()*2;}
 102   else                                                 {return kBad;}
 103
 104   if     (pady>=1         &&pady<= NpadsYsec())     {return -sector;}
 105   else if(pady>NpadsYsec()&&pady<= NpadsY())        {pady-=NpadsYsec();return sector;}
 106   else                                              {return kBad;}
 107 }//Local2Sector()
 108 //__________________________________________________________________________________________________
 109 Int_t AliRICHParam::Local2Pad(Float_t x, Float_t y, Int_t &padx, Int_t &pady)
 110 {//returns pad numbers (iPadX,iPadY) for given point in local coordinates (x,y)
 111  //count starts in lower left corner from 1,1 to 144,180
 112
 113   padx=pady=kBad;
 114   Int_t sector=Local2Sector(x,y);
 115   if(sector==kBad) return sector;
 116
 117   padx=Int_t(x/PadSizeX())+1;
 118   if(padx>NpadsXsec())            padx= NpadsXsec();
 119   if(sector==2||sector==-2)       padx+=NpadsXsec();
 120   else if(sector==3||sector==-3)  padx+=NpadsXsec()*2;
 121
 122   pady=Int_t(y/PadSizeY())+1;
 123   if(pady>NpadsYsec())            padx= NpadsYsec();
 124   if(sector>0)                    pady+=NpadsYsec();
 125
 126   return sector;
 127 }//Local2Pad()
 128 //__________________________________________________________________________________________________
 129 void AliRICHParam::Pad2Local(Int_t padx,Int_t pady,Float_t &x,Float_t &y)
 130 {
 131   Int_t sector=Pad2Sector(padx,pady);
 132   if(sector>0)
 133     y=0.5*DeadZone()+pady*PadSizeY()-0.5*PadSizeY();
 134   else{
 135     sector=-sector;
 136     y=-0.5*PcSizeY()+pady*PadSizeY()-0.5*PadSizeY();
 137   }
 138   if(sector==1)
 139     x=-0.5*PcSizeX()+padx*PadSizeX()-0.5*PadSizeX();
 140   else if(sector==2)
 141     x=-0.5*SectorSizeX()+padx*PadSizeX()-0.5*PadSizeX();
 142   else
 143     x= 0.5*SectorSizeX()+DeadZone()+padx*PadSizeX()-0.5*PadSizeX();
 144   return;
 145 }//Pad2Local()
 146 //__________________________________________________________________________________________________
 147 Float_t AliRICHParam::Gain(Float_t y)
 148 {//Calculates the gain
 149   if(fWireSag){
 150     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;
 151     Float_t gain = (ChargeSlope()+ChargeSlope()*gainK/100)*0.9;
 152     return -gain*TMath::Log(gRandom->Rndm());
 153   }else
 154     return -ChargeSlope()*TMath::Log(gRandom->Rndm());
 155 }//Float_t AliRICHParam::IntPH(Float_t yhit)
 156 //__________________________________________________________________________________________________
 157 Float_t AliRICHParam::TotalCharge(Int_t iPID,Float_t eloss,Float_t y)
 158 {//Get number of electrons and return charge
 159
 160   if(iPID>50000)//it's photon no more then 1 electron after photoelectron conversion
 161     return Gain(y);
 162   else{
 163     Int_t iNelectrons=Int_t(eloss/fEIonisation);if(iNelectrons==0) iNelectrons=1;
 164     Float_t charge=0;
 165     for(Int_t i=1;i<=iNelectrons;i++)
 166       charge+=Gain(y);
 167     return charge;
 168   }
 169 }//Float_t AliRICHParam::TotalCharge(Int_t iPID,Float_t eloss, Float_t y)
 170 //__________________________________________________________________________________________________
 171 void AliRICHParam::FirstPad(Float_t x,Float_t y)
 172 {
 173   Int_t padx,pady;
 174   Local2Pad(x,y,padx,pady);
 175 }//void AliRICHParam::FirstPad(Float_t x,Float_t y)
 176 //__________________________________________________________________________________________________
 177 Float_t AliRICHParam::AssignChargeToPad(Float_t hitx,Float_t hity,Int_t padx,Int_t pady)
 178 {//
 179   Float_t padXcenter=0,padYcenter=0;
 180   Pad2Local(padx,pady,padXcenter,padYcenter);
 181
 182   Float_t xi1=hitx-padXcenter-PadSizeX()/2;
 183   Float_t xi2=hitx-padXcenter+PadSizeX()/2;
 184   Float_t yi1=hity-padYcenter-PadSizeY()/2;
 185   Float_t yi2=hity-padYcenter+PadSizeY()/2;
 186   xi1/=AnodeCathodeGap();
 187   xi2/=AnodeCathodeGap();
 188   yi1/=AnodeCathodeGap();
 189   yi2/=AnodeCathodeGap();
 190 // The Mathieson function
 191   Double_t ux1=SqrtKx3()*TMath::TanH(Kx2()*xi1);
 192   Double_t ux2=SqrtKx3()*TMath::TanH(Kx2()*xi2);
 193   Double_t uy1=SqrtKy3()*TMath::TanH(Ky2()*yi1);
 194   Double_t uy2=SqrtKy3()*TMath::TanH(Ky2()*yi2);
 195   return 4.*Kx4()*(TMath::ATan(ux2)-TMath::ATan(ux1))*Ky4()*(TMath::ATan(uy2)-TMath::ATan(uy1));
 196 }//AssignChargeToPad()
 197 //__________________________________________________________________________________________________