RICH/AliRICHParam.cxx

   1 #include "AliRICHParam.h"
   2 #include <TMath.h>
   3 #include <TRandom.h>
   4 #include <iostream.h>
   5 ClassImp(AliRICHParam)
   6
   7 // RICH main parameters manipulator
   8 //__________________________________________________________________________________________________
   9 AliRICHParam::AliRICHParam():
  10 fCurrentPadX(0),fCurrentPadY(0),fCurrentWire(0),
  11 fSizeZ(0),
  12 fAngleRot(0),fAngleYZ(0),fAngleXY(0),
  13 fOffset(0),
  14 fGapThickness(0),
  15 fProximityGapThickness(0),
  16 fQuartzLength(0),
  17 fQuartzWidth(0),
  18 fQuartzThickness(0),
  19 fOuterFreonLength(0),
  20 fOuterFreonWidth(0),
  21 fInnerFreonLength(0),
  22 fInnerFreonWidth(0),
  23 fFreonThickness(0),
  24 fRadiatorToPads(0),
  25 fChargeSlope(0),
  26 fChargeSpreadX(0),
  27 fChargeSpreadY(0),
  28 fSigmaIntegration(0),
  29 fAlphaFeedback(0),
  30 fEIonisation(0),
  31 fMaxAdc(0),
  32 fWireSag(0),
  33 fVoltage(0)
  34 {//defines the default parameters
  35   Size                 (132.6*kcm,26*kcm,136.7*kcm);  //full length, not GEANT half notation
  36   AngleRot             (-60);                         //rotation of the whole RICH around Z, deg
  37   Angles               (20,19.5);                     //XY angle, YZ angle  deg
  38   Offset               (490*kcm+1.267*kcm);           //1.267???????cm distance from IP to the center of module
  39   GapThickness         (8*kcm);
  40   ProximityGapThickness(0.4*kcm);
  41   QuartzLength         (133*kcm);
  42   QuartzWidth          (127.9*kcm);
  43   QuartzThickness      (0.5*kcm);
  44   OuterFreonLength     (133*kcm);
  45   OuterFreonWidth      (41.3*kcm);
  46   InnerFreonLength     (133*kcm);
  47   InnerFreonWidth      (41.3*kcm);
  48   FreonThickness       (1.5*kcm);
  49   RadiatorToPads       (80*kmm);
  50
  51   ChargeSlope(27.);
  52   ChargeSpreadX(0.18);ChargeSpreadY(0.18);
  53   SigmaIntegration(5.);
  54   MaxAdc(4096);
  55   AlphaFeedback(0.036);
  56   EIonisation(26.e-9);
  57   WireSag(1);                 // 1->On, 0->Off
  58   Voltage(2150);              // Should only be 2000, 2050, 2100 or 2150
  59 }//AliRICHParam::named ctor
  60 //__________________________________________________________________________________________________
  61 Int_t AliRICHParam::Local2Sector(Float_t &x, Float_t &y)
  62 {//Determines sector for a given hit (x,y) and trasform this point to the local system of that sector.
  63   Int_t sector=kBad;
  64   Float_t x1=-0.5*PcSizeX();      Float_t x2=-0.5*SectorSizeX()-DeadZone();  Float_t x3=-0.5*SectorSizeX();
  65   Float_t x4= 0.5*SectorSizeX();  Float_t x5= 0.5*SectorSizeX()+DeadZone();  Float_t x6= 0.5*PcSizeX();
  66
  67   if     (x>=x1&&x<=x2)    {sector=1;x+=0.5*PcSizeX();}
  68   else if(x>=x3&&x<=x4)    {sector=2;x+=0.5*SectorSizeX();}
  69   else if(x>=x5&&x<=x6)    {sector=3;x-=0.5*SectorSizeX()+DeadZone();}
  70   else if(x< x1||x> x6)    {return kBad;}
  71   else                                                        {return kBad;} //in dead zone
  72
  73   if     (y>=-0.5*PcSizeY()   &&y<=-0.5*DeadZone())  {y+=0.5*PcSizeY();  return -sector;}
  74   else if(y> -0.5*DeadZone()  &&y<  0.5*DeadZone())  {return kBad;} //in dead zone
  75   else if(y>= 0.5*DeadZone()  &&y<= 0.5*PcSizeY())   {y-=0.5*DeadZone(); return  sector;}
  76   else                                               {return kBad;}
  77 }//Int_t AliRICHParam::Local2Sector(Float_t x, Float_t y)
  78 //__________________________________________________________________________________________________
  79 Int_t AliRICHParam::Pad2Sector(Int_t &padx, Int_t &pady)
  80 {//Determines sector for a given pad (padx,pady) and trasform this point to the local system of that sector.
  81   Int_t sector=kBad;
  82   if     (padx>=1            &&padx<=NpadsXsec())      {sector=1;}
  83   else if(padx> NpadsXsec()  &&padx<=NpadsXsec()*2)    {sector=2;padx-=NpadsXsec();}
  84   else if(padx> NpadsXsec()*2&&padx<=NpadsX())         {sector=3;padx-=NpadsXsec()*2;}
  85   else                                                 {return kBad;}
  86
  87   if     (pady>=1         &&pady<= NpadsYsec())     {return -sector;}
  88   else if(pady>NpadsYsec()&&pady<= NpadsY())        {pady-=NpadsYsec();return sector;}
  89   else                                              {return kBad;}
  90 }//Local2Sector()
  91 //__________________________________________________________________________________________________
  92 Int_t AliRICHParam::Local2Pad(Float_t x, Float_t y, Int_t &padx, Int_t &pady)
  93 {//returns pad numbers (iPadX,iPadY) for given point in local coordinates (x,y)
  94  //count starts in lower left corner from 1,1 to 144,180
  95
  96   padx=pady=kBad;
  97   Int_t sector=Local2Sector(x,y);
  98   if(sector==kBad) return sector;
  99
 100   padx=Int_t(x/PadSizeX())+1;
 101   if(padx>NpadsXsec())            padx= NpadsXsec();
 102   if(sector==2||sector==-2)       padx+=NpadsXsec();
 103   else if(sector==3||sector==-3)  padx+=NpadsXsec()*2;
 104
 105   pady=Int_t(y/PadSizeY())+1;
 106   if(pady>NpadsYsec())            padx= NpadsYsec();
 107   if(sector>0)                    pady+=NpadsYsec();
 108
 109   return sector;
 110 }//Local2Pad()
 111 //__________________________________________________________________________________________________
 112 void AliRICHParam::Pad2Local(Int_t padx,Int_t pady,Float_t &x,Float_t &y)
 113 {
 114   Int_t sector=Pad2Sector(padx,pady);
 115   if(sector>0)
 116     y=0.5*DeadZone()+pady*PadSizeY()-0.5*PadSizeY();
 117   else{
 118     sector=-sector;
 119     y=-0.5*PcSizeY()+pady*PadSizeY()-0.5*PadSizeY();
 120   }
 121   if(sector==1)
 122     x=-0.5*PcSizeX()+padx*PadSizeX()-0.5*PadSizeX();
 123   else if(sector==2)
 124     x=-0.5*SectorSizeX()+padx*PadSizeX()-0.5*PadSizeX();
 125   else
 126     x= 0.5*SectorSizeX()+DeadZone()+padx*PadSizeX()-0.5*PadSizeX();
 127   return;
 128 }//Pad2Local()
 129 //__________________________________________________________________________________________________
 130 Float_t AliRICHParam::Gain(Float_t y)
 131 {//Calculates the gain
 132   if(fWireSag){
 133     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;
 134     Float_t gain = (ChargeSlope()+ChargeSlope()*gainK/100)*0.9;
 135     return -gain*TMath::Log(gRandom->Rndm());
 136   }else
 137     return -ChargeSlope()*TMath::Log(gRandom->Rndm());
 138 }//Float_t AliRICHParam::IntPH(Float_t yhit)
 139 //__________________________________________________________________________________________________
 140 Float_t AliRICHParam::TotalCharge(Int_t iPID,Float_t eloss,Float_t y)
 141 {//Get number of electrons and return charge
 142
 143   if(iPID>50000)//it's photon no more then 1 electron after photoelectron conversion
 144     return Gain(y);
 145   else{
 146     Int_t iNelectrons=Int_t(eloss/fEIonisation);if(iNelectrons==0) iNelectrons=1;
 147     Float_t charge=0;
 148     for(Int_t i=1;i<=iNelectrons;i++)
 149       charge+=Gain(y);
 150     return charge;
 151   }
 152 }//Float_t AliRICHParam::TotalCharge(Int_t iPID,Float_t eloss, Float_t y)
 153 //__________________________________________________________________________________________________
 154 void AliRICHParam::FirstPad(Float_t x,Float_t y)
 155 {
 156   Int_t padx,pady;
 157   Local2Pad(x,y,padx,pady);
 158 }//void AliRICHParam::FirstPad(Float_t x,Float_t y)
 159 //__________________________________________________________________________________________________
 160 Float_t AliRICHParam::AssignChargeToPad(Float_t hitx,Float_t hity,Int_t padx,Int_t pady)
 161 {//
 162   Float_t padXcenter=0,padYcenter=0;
 163   Pad2Local(padx,pady,padXcenter,padYcenter);
 164
 165   Float_t xi1=hitx-padXcenter-PadSizeX()/2;
 166   Float_t xi2=hitx-padXcenter+PadSizeX()/2;
 167   Float_t yi1=hity-padYcenter-PadSizeY()/2;
 168   Float_t yi2=hity-padYcenter+PadSizeY()/2;
 169   xi1/=AnodeCathodeGap();
 170   xi2/=AnodeCathodeGap();
 171   yi1/=AnodeCathodeGap();
 172   yi2/=AnodeCathodeGap();
 173 // The Mathieson function
 174   Double_t ux1=SqrtKx3()*TMath::TanH(Kx2()*xi1);
 175   Double_t ux2=SqrtKx3()*TMath::TanH(Kx2()*xi2);
 176   Double_t uy1=SqrtKy3()*TMath::TanH(Ky2()*yi1);
 177   Double_t uy2=SqrtKy3()*TMath::TanH(Ky2()*yi2);
 178   return 4.*Kx4()*(TMath::ATan(ux2)-TMath::ATan(ux1))*Ky4()*(TMath::ATan(uy2)-TMath::ATan(uy1));
 179 }//AssignChargeToPad()
 180 //__________________________________________________________________________________________________