Refining Precision Møller Polarimetry for the MOLLER Experiment Using the Magneto-Optical Kerr Effect

Møller polarimetry is an ideal method for measuring the polarization of high-energy electron beams [1]. The upcoming MOLLER experiment at Jefferson Lab aims to make improved high-precision measurements of the electron weak charge from parity-violating Møller scattering and requires ±0.4% precision on beam polarization. This will be dominated by systematic uncertainty, the largest of which arises from the use of a polarized iron foil as our target [2]. Using the Magneto-Optical Kerr Effect, the magnetization saturation curve of the foil can be determined, minimizing this source of uncertainty. Discussion here will focus on the challenges and progress from our apparatus and future plans.