GenGamma

class GenGamma

    private:


    protected:

      float EnergyFracLoss()

    public:

      GenGamma GenGamma()
          void ~GenGamma()
          TF1* GetEDist()
         float GetEElectron()
         float GetEnergy()
         float GetEnergyMin()
         float GetEProton()
         float GetX1()
         float GetX2()
          TF1* GetXDist()
         float GetXPos()
         float GetXsec()
         float GetXTilt()
          TF1* GetYDist()
         float GetYPos()
         float GetYTilt()
         float GetZ()
          TF1* GetZDist()
          void MakeEvent()
          void SetEdist(TF1* newf)
          void SetEElectron(float Eelectron)
          void SetEnergyMin(float Emin)
          void SetEProton(float eproton)
          void SetRadXMean(float newmean)
          void SetRadXMin(float newmin)
          void SetXDist(TF1* newf)
          void SetXTilt(float xtilt)
          void SetXWidth(float xwidth)
          void SetYDist(TF1* newf)
          void SetYTilt(float ytilt)
          void SetYWidth(float ywidth)
          void SetZDist(TF1* newf)
          void Show()

Data Members

    private:

      float fEnergy     photon energy
      float fXPos       photon x-position
      float fYPos       photon y-position
      float fZ          z = Eelec/Egamma
      float fx1         fractional energy loss 1
      float fx2         fractional energy loss 2
      float fEnergyMin  minimum energy for generated photons
      float fXTilt      x position tilt
      float fYTilt      y position tilt
      float fXWidth     x distribution width
      float fYWidth     y distribution width
      float fEproton    Proton beam energy
      float fEelectron  Electron beam energy
      float fRadXmean   mean energy loss
      float fRadXmin    minimum energy loss for MC generation
       TF1* fEdist      Energy distribution of photons: Bethe-Heitler formula
       TF1* fydist      y hit distribution
       TF1* fxdist      x hit distribution
       TF1* fzdist      zdistribution
       TF1* fBethe      Bethe-Heitler
       TF1* fydistgaus  
       TF1* fxdistgaus  

    protected:


    public:

Class Description

• Generate photon with energy according to Bethe-Heitler or custom spectrum defined through SetEDist(TF1 *) with the minimum energy cut set by SetEnergyMin(float energy_min).
• Generate photon position according to Gaussian beam profile or custom provided one. Parameters on the Gaussian can be set by SetXTilt(float tilt), SetXWidth(float width) SetYTilt(float tilt), SetYWidth(float width). The custom beam profile can be set by SetXDist(TF1*) and SetYDist(TF1*) functions where TF1 is a ROOT class for 1dim functions.
• Generate the splitting of photon into e+e- pair. The energy splitting is generated according to GEANT long writeup.
• Generate energy loss in the window. The minimum fractional energy loss is given by the function SetRadXMin(float value) and the average energy loss can be set via SetRadXMean(float value). This is of course relate to the radiation thickness of the window.
• The access to the generated is event is through getters e.g. GetYPos() returns the y-position of the generated photon; GetEnergy() returns the energy of the photon; GetX1() and GetX2() are the fractional energy losses for e- and e+ respectively etc.
• One can also set the parameters for the Bethe-Heitler by SetEElectron(float electron_energy); SetEProton(float proton_energy). This is useful when we run at 12GeV electron injection energy.
• A useful feature in going from the number of events to rates is total cross-section corresponding to generated events. This is provided by GetXsec() method.

Inline Functions

           float EnergyFracLoss()
        GenGamma GenGamma()
            void ~GenGamma()
           float GetEnergyMin()
           float GetXTilt()
           float GetYTilt()
           float GetEProton()
           float GetEElectron()
            TF1* GetEDist()
            TF1* GetYDist()
            TF1* GetXDist()
            TF1* GetZDist()
            void SetEnergyMin(float Emin)
            void SetXTilt(float xtilt)
            void SetYTilt(float ytilt)
            void SetXWidth(float xwidth)
            void SetYWidth(float ywidth)
            void SetEProton(float eproton)
            void SetEElectron(float Eelectron)
            void SetRadXMean(float newmean)
            void SetRadXMin(float newmin)
            void SetEdist(TF1* newf)
            void SetYDist(TF1* newf)
            void SetXDist(TF1* newf)
            void SetZDist(TF1* newf)
           float GetXsec()
           float GetEnergy()
           float GetXPos()
           float GetYPos()
           float GetZ()
           float GetX1()
           float GetX2()
            void MakeEvent()
            void Show()