First experiments with a water-jet plasma X-ray source driven by the novel high-power-high-repetition rate L1 Allegra laser at ELI Beamlines.

Anna Zymaková,Jakob Andreasson,Stefan Karatodorov,Alexandr Špaček,Roman Antipenkov,Jens Uhlig,Martin Albrecht,Ondřej Hort

doi:10.1107/s1600577521008729

Abstract

ELI Beamlines is a rapidly progressing pillar of the pan-European Extreme Light Infrastructure (ELI) project focusing on the development and deployment of science driven by high-power lasers for user operations. This work reports the results of a commissioning run of a water-jet plasma X-ray source driven by the L1 Allegra laser, outlining the current capabilities and future potential of the system. The L1 Allegra is one of the lasers developed in-house at ELI Beamlines, designed to be able to reach a pulse energy of 100 mJ at a 1 kHz repetition rate with excellent beam properties. The water-jet plasma X-ray source driven by this laser opens opportunities for new pump-probe experiments with sub-picosecond temporal resolution and inherent synchronization between pump and probe pulses.

Highlights

The quest to study light-mediated processes has driven the development of facilities capable of producing ultrashort pulses of X-ray radiation (Ponseca et al, 2017; Kranz & Wachtler, 2021; Chergui & Collet, 2017; Milne et al, 2014)
The L1 Allegra laser system is based on a broadband optical parametric chirpedpulse amplification (OPCPA), pumped by picosecond Yb:YAG thin-disc lasers
The difference between the number of events observed in a single pixel and the total number of events observed in any number of pixels is usually kept below 5%, or 20% if each exposed pixel is counted as a separate event, supporting this approach

Summary

Introduction

The quest to study light-mediated processes has driven the development of facilities capable of producing ultrashort pulses of X-ray radiation (Ponseca et al, 2017; Kranz & Wachtler, 2021; Chergui & Collet, 2017; Milne et al, 2014). Laser-driven plasma X-ray sources (PXS) (Mallozzi et al, 1974; Turcu & Dance, 1999; Benesch et al, 2004) are based on focusing a laser with ultrashort (sub-100 fs) pulse durations and a peak intensity of 1015–1017 W cmÀ2 onto a renewable target (Fullagar, Harbst et al, 2007; Korn et al, 2002; Zamponi et al, 2009; Uhlig et al, 2013; Weisshaupt et al, 2014; Afshari et al, 2020). PXS sources have shown a strong dependence on the electron temperature and integral flux of the driving power and on the precise interaction conditions (Miaja-Avila et al, 2015; Fullagar, Harbst et al, 2007) Based on these results, we will carefully estimate the perspective of the expected source X-ray flux and experimental conditions as the L1 Allegra laser approaches its design pulse energy of 100 mJ

Experimental

Characterization of this source for X-ray emission spectroscopy

Characterization of the direct flux and X-ray absorption spectrum

Discussion of average and peak flux

Findings

Summary and outlook