CLAS Cerenkov efficiency for out-bending electrons

Source data and procedure

EG1B out-bending data at 1.6 initial energy GeV were used. Fig. 1 shows the number of detected electrons as a function of angles Theta, Phy from a target summarized for all 6 sectors. The curve on the Fig. 2 and thereafter - Fiducial cut from in-bending data.
Electrons were identified using missing mass distribution, EC deposited energy, SC deposited energy, SC status cut (SC status = 33) was applied. SC status plot shows that most events are good enough and there are no SC paddle with permanently missing ADC or TDC.
To analyze data I used projective angles Theta and Phy, - Theta and Phy from the target to the cross-point of an electron track with "Cerenkov plane", - plane parallel to EC plane about in the center of EC. Fig. 2 shows the same as Fig.1 number of detected electrons as a function of projective angles Theta, Phy summarized for all 6 sectors.
Fig.3 shows the number of non-detected electrons as a function of projective Theta, Phy summarized over all 6 sectors. Those events with EC only trigger were used to identify electrons and define the electron efficiency.
Fig.4 shows the electron inefficiency for every CLAS sector.
Fig.5 shows the mean number of photo-electrons for every CLAS sector.
To calculate the efficiency function, the inefficiency was plotted as a function of the MEAN NUMBER of photoelectrons at the same projective Theta, Phy cell. ( Fig.6 ) Only events within Fiducial cut was used. The curve on the Fig.6 is a data fit. The deviation from the Poisson distribution behavior can be understanded

I've produced a function for using this efficiency for out-bending runs analysis. It is based on eg1b 1.6 GeV outbending data.

Function name is int cceffn_out(int run_number, int sector_number, float *point, float *dir, float *Nphe,float *Nphe_err, float *cc_eff, float *Theta, float *Phy);

C- Inputs : run_number - number of a run - to trace possible
C- changes in efficiency
C- sector_number - number of the sector
C- point(3) - coordinates of the point on the track
C- somewhere after CC (where B=0):
C- it could be EC or SC matching point.
C- dir(3) - direction vector at that point.
C- *** IMPORTANT ! *** Point and direction must be in Sector RS
C-
C- Outputs : Nphe - estimated number of photoelectrons
C- for the track.
C- Nphe_err - estimated error in Nphe
C- cc_eff - estimated Cerenkov detector efficiency
C- theta, phy - projective angles from the target
C- to the track cross-point with "special Cerenkov plane".
C-
C- Controls: Function returnes :
C- C- 0 : no errors
C- -1 : can't read initialization file
C- -2 : Wrong sector number ( must be from 1 to 6 ) C- -3 : No crossing with the plane - check coordinates
C- and direction - possible wrong coordinate system
C- -4 : Not enough data to define efficiency
C-
C- Created 11-AUG-2003 Alexander V. Vlassov
C-
C----------------------------------------------------------------------

It is a full analog of cceffn1 function but only for outbending electrons. More info can be find at http://www.jlab.org/~vlassov/cc/cc_outbend/index.html

Any comments / suggestions are appreciated !

Mail to me!