First electron beam polarization measurements with a Compton polarimeter at Jefferson Laboratory
arXiv:hep-ex/0203012 · doi:10.1016/S0370-2693(02)02091-9
Abstract
A Compton polarimeter has been installed in Hall A at Jefferson Laboratory. This letter reports on the first electron beam polarization measurements performed during the HAPPEX experiment at an electron energy of 3.3 GeV and an average current of 40 $μ$A. The heart of this device is a Fabry-Perot cavity which increased the luminosity for Compton scattering in the interaction region so much that a 1.4% statistical accuracy could be obtained within one hour, with a 3.3% total error.