A Spin-Light Polarimeter for Multi-GeV Longitudinally Polarized Electron Beams

Abstract

Abstract-The physics program at the upgraded Jefferson Lab (JLab) and the physics program envisioned for the proposed electron-ion collider (EIC) include large efforts to search for interactions beyond the Standard Model (SM) using parity violation in electroweak interactions. These experiments require precision electron polarimetry with an uncertainty of < 0.5 %. The spin dependent Synchrotron radiation (SR), called "spinlight," can be used to monitor the electron beam polarization. In this article we develop a conceptual design for a "spin-light" polarimeter that can be used at a high intensity, multi-GeV electron accelerator. We have also built a Geant4 based simulation for a prototype device and report some of the results from these simulations.

A toy Monte Carlo simulation for the transverse polarization of high-energy electron beams

“…By measuring spin dependence in the total synchrotron radiation (SR) power radiated, one can measure the transverse polarization of electron beam. Moreover, the spatial asymmetry of SR is longitudinal-spin dependent [16,17]. The feasibility of SR measurement limits the beam energy and current, which is best suited for the 4-20 GeV energy range, for current less than mA [16].…”

“…Moreover, the spatial asymmetry of SR is longitudinal-spin dependent [16,17]. The feasibility of SR measurement limits the beam energy and current, which is best suited for the 4-20 GeV energy range, for current less than mA [16].…”