Laser-Induced Linear Electron Acceleration in Free Space

TL;DR

This paper develops a comprehensive theoretical model to explore the potential of laser-induced linear electron acceleration in free space, demonstrating significant energy gains in electrons with minimal energy spread.

Contribution

The authors present an exact, predictive formalism for free-space laser electron acceleration, including full Maxwell and relativistic particle interactions, which is novel in this research area.

Findings

Electrons can be accelerated from 30 keV to 7.7 MeV with 2.5% energy spread.

Electrons can reach 205 MeV with 0.25% energy spread using high-energy lasers.

The results suggest potential for compact, high-quality electron sources.

Abstract

Linear acceleration in free space is a topic that has been studied for over 20 years, and its ability to eventually produce high-quality, high energy multi-particle bunches has remained a subject of great interest. Arguments can certainly be made that such an ability is very doubtful. Nevertheless, we chose to develop an accurate and truly predictive theoretical formalism to explore this remote possibility in a computational experiment. The formalism includes exact treatment of Maxwell's equations, exact relativistic treatment of the interaction among the multiple individual particles, and exact treatment of the interaction at near and far field. Several surprising results emerged. For example, we find that 30 keV electrons (2.5% energy spread) can be accelerated to 7.7 MeV (2.5% spread) and to 205 MeV (0.25% spread) using 25 mJ and 2.5 J lasers respectively. These findings should hopefully guide and help develop compact, high-quality, ultra-relativistic electron sources, avoiding conventional limits imposed by material breakdown or structural constraints.