Fast electron generation by Coulomb scattering on spatially correlated ions in a strong laser field

TL;DR

This paper investigates how Coulomb scattering on spatially correlated ions in strong laser fields can generate fast electrons, analyzing mechanisms, energy spectra, and methods to enhance electron acceleration.

Contribution

It introduces a detailed analysis of electron acceleration via Coulomb scattering in strong laser fields, including multi-collision strategies and confinement techniques to boost high-energy electron production.

Findings

Multi-collision collisions significantly increase maximum electron energy.

External confinement enhances electron focusing and energy output.

2D systems show reduced efficiency without confinement.

Abstract

Electrons colliding with spatially fixed ions in strong laser fields are investigated by solving the time-dependent Schr\"odinger equation. Considering first simple one-dimensional model systems, the mechanisms and energy spectra of fast electrons are analyzed, starting from collisions on a single ion. By using these electrons as projectiles for a second and third collision, the maximum possible energy obtained can be significantly increased. We then generalize the analysis to 2D systems where additional angular degrees of freedom lead to a drastic loss of efficiency. This problem can be overcome by introducing external confinements, which allow to focus the electrons and increase the intensity of high-energy electrons.