RICH/AliRICHParam.cxx

   1 #include "AliRICHParam.h"
   2 #include <TMath.h>
   3 #include <TRandom.h>
   4
   5 ClassImp(AliRICHParam)
   6
   7 // RICH main parameters manipulator
   8 //__________________________________________________________________________________________________
   9 AliRICHParam::AliRICHParam():
  10 fDeadZone(0),
  11 fPadSizeX(0),fPadSizeY(0),
  12 fCurrentPadX(0),fCurrentPadY(0),fCurrentWire(0),
  13 fSizeZ(0),
  14 fAngleRot(0),fAngleYZ(0),fAngleXY(0),
  15 fOffset(0),
  16 fGapThickness(0),
  17 fProximityGapThickness(0),
  18 fQuartzLength(0),
  19 fQuartzWidth(0),
  20 fQuartzThickness(0),
  21 fOuterFreonLength(0),
  22 fOuterFreonWidth(0),
  23 fInnerFreonLength(0),
  24 fInnerFreonWidth(0),
  25 fFreonThickness(0),
  26 fRadiatorToPads(0),
  27 fChargeSlope(0),
  28 fChargeSpreadX(0),
  29 fChargeSpreadY(0),
  30 fSigmaIntegration(0),
  31 fAlphaFeedback(0),
  32 fEIonisation(0),
  33 fMaxAdc(0),
  34 fSqrtKx3(0),
  35 fKx2(0),
  36 fKx4(0),
  37 fSqrtKy3(0),
  38 fKy2(0),
  39 fKy4(0),
  40 fPitch(0),
  41 fWireSag(0),
  42 fVoltage(0)
  43 {//defines the default parameters
  44   DeadZone             (3);                 //spacer between PC planes
  45   PadSize              (0.84,0.80);
  46
  47   Size                 (132.6*kcm,26*kcm,136.7*kcm);  //full length, not GEANT half notation
  48   AngleRot             (-60);                         //rotation of the whole RICH around Z, deg
  49   Angles               (20,19.5);                     //XY angle, YZ angle  deg
  50   Offset               (490*kcm+1.267*kcm);           //1.267???????cm distance from IP to the center of module
  51   GapThickness         (8*kcm);
  52   ProximityGapThickness(0.4*kcm);
  53   QuartzLength         (133*kcm);
  54   QuartzWidth          (127.9*kcm);
  55   QuartzThickness      (0.5*kcm);
  56   OuterFreonLength     (133*kcm);
  57   OuterFreonWidth      (41.3*kcm);
  58   InnerFreonLength     (133*kcm);
  59   InnerFreonWidth      (41.3*kcm);
  60   FreonThickness       (1.5*kcm);
  61   RadiatorToPads       (80*kmm);
  62
  63   ChargeSlope(27.);
  64   ChargeSpreadX(0.18);ChargeSpreadY(0.18);
  65   SigmaIntegration(5.);
  66   MaxAdc(4096);
  67   AlphaFeedback(0.036);
  68   EIonisation(26.e-9);
  69   SqrtKx3(0.77459667);
  70   Kx2(0.962);
  71   Kx4(0.379);
  72   SqrtKy3(0.77459667);
  73   Ky2(0.962);
  74   Ky4(0.379);
  75   Pitch(0.25);
  76   WireSag(1);                 // 1->On, 0->Off
  77   Voltage(2150);              // Should only be 2000, 2050, 2100 or 2150
  78 }//AliRICHParam::named ctor
  79 //__________________________________________________________________________________________________
  80 Int_t AliRICHParam::Local2Sector(Float_t &x, Float_t &y)const
  81 {//Determines sector for a given hit (x,y) and trasform this point to the local system of that sector.
  82   Int_t sector=kBad;
  83   Float_t x1=-0.5*PcSizeX();      Float_t x2=-0.5*SectorSizeX()-DeadZone();  Float_t x3=-0.5*SectorSizeX();
  84   Float_t x4= 0.5*SectorSizeX();  Float_t x5= 0.5*SectorSizeX()+DeadZone();  Float_t x6= 0.5*PcSizeX();
  85
  86   if     (x>=x1&&x<=x2)    {sector=1;x+=0.5*PcSizeX();}
  87   else if(x>=x3&&x<=x4)    {sector=2;x+=0.5*SectorSizeX();}
  88   else if(x>=x5&&x<=x6)    {sector=3;x-=0.5*SectorSizeX()+DeadZone();}
  89   else if(x< x1||x> x6)    {Error("Sector","given x position is out of PC area");return kBad;}
  90   else                                                        {return kBad;} //in dead zone
  91
  92   if     (y>=-0.5*PcSizeY()   &&y<=-0.5*DeadZone())  {y+=0.5*PcSizeY();  return -sector;}
  93   else if(y> -0.5*DeadZone()  &&y<  0.5*DeadZone())  {return kBad;} //in dead zone
  94   else if(y>= 0.5*DeadZone()  &&y<= 0.5*PcSizeY())   {y-=0.5*DeadZone(); return  sector;}
  95   else                                            {Error("Sector","given y position is out of PC area");return kBad;}
  96 }//Int_t AliRICHParam::Local2Sector(Float_t x, Float_t y)
  97 //__________________________________________________________________________________________________
  98 Int_t AliRICHParam::Pad2Sector(Int_t &padx, Int_t &pady)const
  99 {//Determines sector for a given pad (padx,pady) and trasform this point to the local system of that sector.
 100   Int_t sector=kBad;
 101   if     (padx>=1            &&padx<=NpadsXsec())      {sector=1;}
 102   else if(padx> NpadsXsec()  &&padx<=NpadsXsec()*2)    {sector=2;padx-=NpadsXsec();}
 103   else if(padx> NpadsXsec()*2&&padx<=NpadsX())         {sector=3;padx-=NpadsXsec()*2;}
 104   else                                   {Error("Sector","given padx position is out of PC area");return kBad;}
 105
 106   if     (pady>=1         &&pady<= NpadsYsec())     {return -sector;}
 107   else if(pady>NpadsYsec()&&pady<= NpadsY())        {pady-=NpadsYsec();return sector;}
 108   else                                              {Error("Sector","given y position is out of PC area");return kBad;}
 109 }//Local2Sector()
 110 //__________________________________________________________________________________________________
 111 Int_t AliRICHParam::Local2Pad(Float_t x, Float_t y, Int_t &padx, Int_t &pady)const
 112 {//returns pad numbers (iPadX,iPadY) for given point in local coordinates (x,y)
 113  //count starts in lower left corner from 1,1 to 144,180
 114
 115   padx=pady=kBad;
 116   Int_t sector=Local2Sector(x,y);
 117   if(sector==kBad) return sector;
 118
 119   padx=Int_t(x/PadSizeX())+1;
 120   if(padx>NpadsXsec())            padx= NpadsXsec();
 121   if(sector==2||sector==-2)       padx+=NpadsXsec();
 122   else if(sector==3||sector==-3)  padx+=NpadsXsec()*2;
 123
 124   pady=Int_t(y/PadSizeY())+1;
 125   if(pady>NpadsYsec())            padx= NpadsYsec();
 126   if(sector>0)                    pady+=NpadsYsec();
 127
 128   return sector;
 129 }//Local2Pad()
 130 //__________________________________________________________________________________________________
 131 void AliRICHParam::Pad2Local(Int_t padx,Int_t pady,Float_t &x,Float_t &y)
 132 {
 133   Int_t sector=Pad2Sector(padx,pady);
 134   if(sector>0)
 135     y=0.5*DeadZone()+pady*PadSizeY()-0.5*PadSizeY();
 136   else{
 137     sector=-sector;
 138     y=-0.5*PcSizeY()+pady*PadSizeY()-0.5*PadSizeY();
 139   }
 140   if(sector==1)
 141     x=-0.5*PcSizeX()+padx*PadSizeX()-0.5*PadSizeX();
 142   else if(sector==2)
 143     x=-0.5*SectorSizeX()+padx*PadSizeX()-0.5*PadSizeX();
 144   else
 145     x= 0.5*SectorSizeX()+DeadZone()+padx*PadSizeX()-0.5*PadSizeX();
 146   return;
 147 }//Pad2Local()
 148 //__________________________________________________________________________________________________
 149 Float_t AliRICHParam::Gain(Float_t y)
 150 {//Calculates the gain
 151   if(fWireSag){
 152     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;
 153     Float_t gain = (ChargeSlope()+ChargeSlope()*gainK/100)*0.9;
 154     return -gain*TMath::Log(gRandom->Rndm());
 155   }else
 156     return -ChargeSlope()*TMath::Log(gRandom->Rndm());
 157 }//Float_t AliRICHParam::IntPH(Float_t yhit)
 158 //__________________________________________________________________________________________________
 159 Float_t AliRICHParam::TotalCharge(Int_t iPID,Float_t eloss,Float_t y)
 160 {//Get number of electrons and return charge
 161
 162   if(iPID>50000)//it's photon no more then 1 electron after photoelectron conversion
 163     return Gain(y);
 164   else{
 165     Int_t iNelectrons=Int_t(eloss/fEIonisation);if(iNelectrons==0) iNelectrons=1;
 166     Float_t charge=0;
 167     for(Int_t i=1;i<=iNelectrons;i++)
 168       charge+=Gain(y);
 169     return charge;
 170   }
 171 }//Float_t AliRICHParam::TotalCharge(Int_t iPID,Float_t eloss, Float_t y)
 172 //__________________________________________________________________________________________________
 173 void AliRICHParam::FirstPad(Float_t x,Float_t y)
 174 {
 175   Int_t padx,pady;
 176   Local2Pad(x,y,padx,pady);
 177 }//void AliRICHParam::FirstPad(Float_t x,Float_t y)