Effects of initial spin orientation on the generation of polarized electron beams from laser wakefield acceleration in plasma

TL;DR

This paper investigates how the initial spin orientation affects the polarization of electron beams generated by laser wakefield acceleration in plasma, revealing that longitudinal injection yields higher polarization.

Contribution

It provides a theoretical and numerical analysis of spin dynamics in laser wakefield acceleration, highlighting the impact of injection schemes on electron beam polarization.

Findings

Longitudinal injection produces more highly polarized electron beams.

Wakefields and laser fields significantly influence spin dynamics.

Theoretical and simulation approaches confirm the dependence on initial spin orientation.

Abstract

The effects of the initial spin orientation on the final electron beam polarization via laser wakefield acceleration in pre-polarized plasma are investigated theoretically and numerically. From a variation of the initial spin direction, the spin dynamics of the electron beam is found to depend on the self-injection mechanism. The effects of wakefields and laser fields are studied using test particle dynamics and particle-in-cell simulation based on the Thomas-Bargmann-Michel-Telegdi equation, respectively. Compared to the case of transverse injection, the scheme of longitudinal injection is more favorable to obtain a highly polarization electron beam.