A Lead Fluoride Calorimeter for the Hall A DVCS Experiment

A 132-block PbF₂ electromagnetic calorimeter has been built in Jefferson Lab Hall A for use in the upcoming Deeply Virtual Compton Scattering (DVCS) experiment. This calorimeter will be used to detect high energy photons ( ∼1.5-3.5 GeV) as part of a triple-coincidence measurement of the exclusive reaction ep arrow epγ. The scattered electron and recoiling proton will be detected in one of the Hall A high resolution spectrometers and in a scintillator array, respectively. Construction of the calorimeter finished in 2003. Since then, the system has been tested with cosmic rays. It has also been tested with a light emitting diode (LED) scanner array which is part of the calibration and gain monitoring system. The design and construction of the calorimeter will be described, as well as the current state of cosmic and LED testing.