Multiple ionization of argon via xuv-photon absorption induced by 20-gigawatt high-harmonic pulses

TL;DR

This paper demonstrates multiple ionization of argon atoms using high-harmonic-generation pulses from a powerful laser source, revealing complex ionization channels and connecting nonlinear XUV processes with ultrafast timescales.

Contribution

It provides the first experimental observation of multi-ionization of argon with high-harmonic pulses and compares results with numerical models to identify ionization pathways.

Findings

Identification of direct and sequential ionization channels.

Correlation between intensity and ionization yield.

Potential for studying ultrafast nonlinear XUV processes.

Abstract

We report the observation of multiple ionization of Argon through multi-XUV-photon absorption induced by an unprecedentedly powerful laser driven high-harmonic-generation source. Comparing the measured intensity dependence of the yield of the different Argon charge states with numerical calculations we can infer the different channels -direct and sequential- underlying the interaction. While such studies were feasible so far only with FEL sources, this work connects highly-non-linear-XUV-processes with the ultra-short time scales, inherent to the harmonic pulses, and highlights the advanced perspectives of emerging large scale laser research infrastructures.