Photon Tagger E-Counters

The E-counters in the photon tagger are used to determine the energy of the beam photons to an accuracy of ~0.1%. The stability of these detectors is crucial to measuring the photon flux to within 1% as required by PrimEx.


  • September 27, 2004: Here are links to the files of the tagger E-counter and T-counter energies at E0=5.75 GeV: T_ctrs_575.dat, E_ctrs_575.dat.

  • March 2003: E-counter Replacement. (HTML page)

  • December 2002: Beam test of New Discriminator/Scalers. (HTML page)

  • November 13, 2002: Plateau results from G7. (HTML page)


    Here are some occupancy plots made from E-counters EPICS scalers in the final day of the CLAS G7 run on November 12th, 2002.

    Here are the E-counters on a linear scale with 50nA of beam on a 3x10-3 r.l.radiator.
    Here is the same picture as above, only on a log scale.
    Here is the linear scale again, only zoomed in on the top 100 E-counters. These are the E-counters which will be used by PrimEx.


    Below is a list of files in the primex/subsystems/tagger/files folder. Put your file in that directory and refresh this page to have it appear on the list. The files are shown in alphabetical order, so it may be useful to append "year-month-date" to your filename.

    empty_folder.txt