Compact Petawatt-Class Laser Wakefield Acceleration with Plasma Telescope

TL;DR

This paper introduces a plasma mirror telescope design that significantly reduces the focal length of petawatt-class laser wakefield accelerators, enabling more compact setups for ultra-high-power lasers.

Contribution

It proposes a plasma-based off-axial parabolic mirror to miniaturize LWFA systems driven by lasers beyond 1PW, demonstrated through simulations.

Findings

Achieves meter-range focal length with plasma mirror

Generates 9 GeV electron bunches with 1-PW laser

Maintains high acceleration gradients in compact setup

Abstract

The compactness of laser wakefield acceleration (LWFA) is limited by its long focal length for high power lasers, e.g., more than 10 meters for 1-peatawatt (PW) laser pulse and up to hundreds of meters for 10-100 PW lasers. The long focal length originates from the low damage threshold of the optical off-axial parabolic (OAP) mirror and consequent large spot size. We propose implementing an OAP plasma mirror (PM) to form a telescope geometry, reducing the beam size and hence constraining the focal length to meter-range for LWFA driven by lasers beyond 1PW. Three-dimensional particle-in-cell simulations are performed to characterize the reflection of a 1-PW laser by the plasma OAP and find that optimal condition is achieved within only 1-m optical length. The new method successfully generates 9GeV electron bunch in the subsequent LWFA stage with consistent acceleration gradients to that of the 1-PW laser via ordinary focusing. The proposed geometry provides a solution of compact LWFAs available for even 100-PW laser systems.