High Resolution Tagger Hodoscope .

An intensity, high resolution tagged photon beam is critical for the highly rated experiments in Hall D at Jefferson Lab, such as the GlueX experiment and PrimEx-eta experiment. It is produced by a high energy electron beam off a thin radiator. The energies of resulting photons are measured by a Broadband Tagger Hodoscope (TAGH) with a dipole magnet. I tested and repaired the TAGH counters as my summer research project. The procedure and the result of this work will be reported.