Achieving High Efficiency And Enhanced Beam Quality In Laser Wakefield Acceleration

TL;DR

This paper presents a method to improve efficiency and beam quality in laser wakefield acceleration by using shorter laser pulses and a two-step dechirping process, achieving high-energy, low-spread electron beams.

Contribution

It introduces a novel approach combining shorter laser pulses and dechirping to enhance energy transfer efficiency and beam quality in laser wakefield acceleration.

Findings

Achieved 10-30% energy transfer efficiency.

Generated 420 MeV electron beams with 2% energy spread.

Produced high-charge electron beams with 5.5 nC charge.

Abstract

Laser wakefield acceleration, characterized by the extremely high electric field gradient exceeding 100GV/m, is regarded as a compact and cost affordable technology for the next generation of particle colliders and light sources. However, it has always been a major challenge to effectively increase the energy transfer efficiency from the laser to the accelerated beam, while ensuring the beam quality remains suitable for practical applications. This study demonstrates that the laser with shorter pulse duration allows for a two-step dechirping process of the accelerated electron beam with charge of nanocoulomb level. The electron beams with an energy spread of 1% can be generated with the energy transfer efficiency of 10% to 30% in a large parameter space. For example, one electron beam with the energy of 420MeV, the charge of 5.5nC and the RMS energy spread of 2% can be produced using an 8.3J laser pulse with 7.2fs duration.