Development of the Low Granularity Pair Spectrometer counters in Hall D at JLab

The pair spectrometer in the photon beam line of Hall D at JLab is designed to monitor the stability of photon flux and the relative tagging efficiency of the photon tagger via a well known electron-positron pair production measurement. The pair spectrometer consists of a thin foil converter, a dipole magnet, and two identical left and right arm detector packages. Each detector package covers the electron or position energy from 3 GeV to 6.25 GeV. It consists of a front detector array for fine position resolution and rear scintillating hodoscopes to provide fast timing to form the pair production trigger. This presentation will focus on the construction and testing of the Low-Granularity Pair Spectrometer counters.