Pinching injection in wakefields for spin-polarized electron beams

TL;DR

This paper proposes a novel method utilizing driver beam pinching in plasma wakefield acceleration to inject spin-polarized electron beams, preserving electron spin and easing target restrictions.

Contribution

It introduces a new injection scheme that leverages beam pinching, enabling spin-polarized electron injection and improving upon existing methods with hydrogen halide targets.

Findings

Electron spin is preserved at 50% during injection.

The scheme works across a wide range of parameters.

It offers a pathway to relax restrictions on target polarization.

Abstract

Pinching of the driver beam in plasma wakefield acceleration is generally considered an unwanted effect that needs to be mitigated. Here, we propose that this effect can be utilized for the injection of spin-polarized electron beams from hydrogen halide targets into wakefields. Particle-in-cell simulations show that the electron spin is preserved on a level of 50% for a wide range of parameters due to the injection geometry. The presented injection scheme provides a possible pathway to alleviate some of the restrictions associated with pre-polarized hydrogen halide targets.