Controlled Injection in a Laser Plasma Accelerator via an Optically Generated Waveguide Constriction

TL;DR

This paper introduces an all-optical method to control electron injection in laser plasma accelerators, enabling the production of high-quality, tunable electron beams with significant energy and low spread.

Contribution

It presents a novel constricted waveguide injection technique that creates a controllable plasma structure within a waveguide for improved electron acceleration.

Findings

Generated a 1.1 GeV electron beam with 10 pC charge

Achieved 0.35% energy spread in simulations

Demonstrated tunability of plasma sources for better control

Abstract

We propose a novel scheme for controlling the injection of a high-quality electron bunch into a channel-guided laser plasma accelerator. This all-optical technique, constricted waveguide injection, creates a highly tunable controlled injection structure natively within a plasma waveguide, a key requirement for efficient acceleration of high-quality multi-GeV electron beams. We describe a simple optical setup to tailor the plasma and present start-to-end simulations showing the injection structure formation and the generation of a 1.1 GeV electron beam with 10 pC of charge and 0.35 % energy spread using 1 J of drive laser energy. Highly tunable tailored plasma sources, like those proposed here, enable fine control over the injection and acceleration processes and thus will be crucial for the development of application-focused laser plasma accelerators.