The SLAC Polarized Electron Source and Beam for E-158

TL;DR

This paper reports on the performance of SLAC's polarized electron source and beam during E-158's initial physics run, aiming to measure parity violation in Moller scattering with high precision.

Contribution

It provides detailed performance data of the polarized electron source and beam for the first physics run of E-158, enabling precise parity violation measurements.

Findings

Successful operation of the polarized electron source

Achievement of the desired beam polarization and stability

Preparation for high-precision asymmetry measurement

Abstract

SLAC E-158 is making the first measurement of parity violation in Moller scattering. E-158 measures the right-left cross-section asymmetry, A_LR, in the scattering of a 45-GeV polarized electron beam off unpolarized electrons in a liquid hydrogen target. E-158 plans to measure the expected Standard Model asymmetry of ~10^-7 to an accuracy of better than 10^-8. This paper discusses the performance of the SLAC polarized electron source and beam during E-158's first physics run in April/May 2002.