# Extremely intense laser-based electron acceleration in a plasma channel

## TL;DR

This paper investigates how ultra-intense laser pulses create plasma channels in near-critical gases and enable electrons to reach multi-GeV energies through direct laser acceleration, considering the effects of radiation reaction.

## Contribution

It provides a detailed analysis of plasma channel formation and electron acceleration mechanisms at extreme laser intensities, highlighting the role of radiation reaction effects.

## Key findings

- Radiation reaction influences electron trajectories and energy gain.
- Electrons can reach multi-GeV energies within the plasma channel.
- Channel formation is driven by laser prepulse-induced plasma expansion.

## Abstract

Laser pulses of extreme intensities ($I>10^{22}~ \mathrm{W/cm^2}$) are about to become available in the laboratory. The prepulse of such a laser can induce a plasma expansion that generates a low-density channel in near-critical gas jets. We present a study of channel formation and subsequent direct laser acceleration of electrons within the pre-formed channel. Radiation reaction affects the acceleration in several ways. It first interferes with the motion of the return current on the channel walls. In addition, it reduces the radial expelling efficiency of the transverse ponderomotive force, leading to the radiative trapping of particles near the channel axis. These particles then interact with the peak laser intensity and can attain multi-GeV energies.