Upgraded photon calorimeter with integrating readout for Hall A Compton Polarimeter at Jefferson Lab

摘要

The photon arm of the Compton polarimeter in Hall A of Jefferson Lab has beenupgraded to allow for electron beam polarization measurements with better than1% accuracy. The data acquisition system (DAQ) now includes an integratingmode, which eliminates several systematic uncertainties inherent in theoriginal counting-DAQ setup. The photon calorimeter has been replaced with aCe-doped GSO crystal, which has a bright output and fast response, and workswell for measurements using the new integrating method at electron beamenergies from 1 to 6 GeV.