Meter-scale supersonic gas jets for multi-GeV laser-plasma accelerators

TL;DR

This paper reports the development of meter-scale supersonic gas jets suitable for multi-GeV laser-plasma accelerators, enabling longer plasma channels for higher energy electron acceleration.

Contribution

It introduces two types of supersonic gas jets, including the longest gas jet laser plasma to date, with demonstrated uniformity and density control for extended LWFA experiments.

Findings

Successful creation of 1.0-meter-long hydrogen plasma

Demonstrated density profile control with modular jets

Achieved uniform axial gas flow in long jets

Abstract

Pushing the high energy frontier of laser wakefield electron acceleration (LWFA) to 10 GeV and beyond requires extending the propagation of relativistic intensity pulses to ~1 m in a low density ($N_e\sim 10^{17} cm^{-3}$) plasma waveguide. We present the development and characterization of two types of supersonic gas jet for meter-scale multi-GeV laser wakefield accelerators. The first type is a 30-cm long single-module gas jet, which demonstrates good axial uniformity using hydrogen, the preferred working gas for LWFA. The second type is a modular jet composed of multiple 11-cm-long modules. Longitudinal density profile control is demonstrated with a 2-module (22 cm long) hydrogen jet using gas valve trigger timing. A 1.0-m-long jet is then assembled from 9 modules, and generation of 1.0-m long hydrogen plasma is demonstrated using a femtosecond Bessel beam. To our knowledge, this is the longest gas jet laser plasma yet generated.