Laser-plasma acceleration in a conical plasma channel with longitudinally inhomogeneous plasma profile

TL;DR

This paper explores how a conical plasma channel with a longitudinally increasing density profile enhances laser-plasma acceleration by maintaining the wakefield phase and increasing the energy of self-injected bunches, outperforming homogeneous channels.

Contribution

It introduces the use of a longitudinally inhomogeneous plasma density gradient in a conical channel to improve acceleration efficiency and energy gain in laser-plasma accelerators.

Findings

Inhomogeneous plasma increases the accelerating gradient.

Conical geometry prevents laser pulse expansion and compression.

Combined effects lead to higher bunch energy and momentum.

Abstract

Laser-plasma acceleration is considered as a modern method of accelerating bunches using a wakefield excited by a laser pulse. This paper demonstrates the use of a longitudinally inhomogeneous increasing plasma density gradient in a conical channel to increase of the energy of a self-injected bunch. Comparison of a conical channels with homogeneous and inhomogeneous plasma and also conical and cylindrical homogeneous channels, shows a clear advantage of an inhomogeneous conical channel. The longitudinally inhomogeneous plasma helps to maintain the self-injected bunch in the wakefield acceleration phase and increases the accelerating gradient. The conical geometry prevents laser pulse expanding, and compress it. The combined effect was shown: the inhomogeneous plasma use, the effect of a conical geometry led to significant increasing the accelerating gradient and longitudinal momentum of the bunch.