# Mapping electromagnetic fields structure in plasma using a spin polarized electron beam

## TL;DR

This paper introduces a novel method for mapping electromagnetic fields in plasma using spin polarized relativistic electron beams, combining PIC and spin tracing simulations to reconstruct plasma wakefields.

## Contribution

The study demonstrates a new approach to reconstruct plasma electromagnetic fields by analyzing spin evolution of a polarized electron beam through combined simulations.

## Key findings

- Successfully reconstructed plasma wakefield from spin evolution data.
- Validated the feasibility of using spin polarized electron beams for field detection.
- Demonstrated main features of original fields through reconstructed data.

## Abstract

We propose a scheme to mapping electromagnetic fields structure in plasma by using a spin polarized relativistic electron beam. Especially by using Particle-in-Cell (PIC) and electron spin tracing simulations, we have successfully reconstructed a plasma wakefield from the spin evolution of a transmitted electron beam. Electron trajectories of the probe beam are obtained from PIC simulations, and the spin evolutions during the beam propagating through the fields are calculated by a spin tracing code. The reconstructed fields illustrate the main characters of the original fields, which demonstrates the feasibility of fields detection by use of spin polarized relativistic electron beams.