Electron Spin Precession at CEBAF

TL;DR

This paper discusses a method to enhance the polarization of electrons delivered to multiple experimental halls at CEBAF by redistributing energy gain in the accelerator, improving experimental outcomes.

Contribution

It introduces a novel approach to optimize electron polarization by adjusting energy gain distribution without changing total energy, beyond traditional initial spin adjustments.

Findings

Improved polarization delivery to multiple halls.

Energy redistribution enhances polarization without increasing total energy.

Method maintains overall accelerator energy while optimizing polarization.

Abstract

The nuclear physics experiments at the Thomas Jefferson National Accelerator Facility often require longitudinally polarized electrons to be simultaneously delivered to three experimental halls. The degree of longitudinal polarization to each hall varies as function of the accelerator settings, making it challenging in certain situations to deliver a high degree of longitudinal polarization to all the halls simultaneously. Normally, the degree of longitudinal polarization the halls receive is optimized by changing the initial spin direction at the beginning of the machine with a Wien filter. Herein, it is shown that it is possible to further improve the degree of longitudinal polarization for multiple experimental halls by redistributing the energy gain of the CEBAF linacs while keeping the total energy gain fixed.