Diffractive imaging of transient electronic core-shell structures in a nanoplasma

TL;DR

This paper demonstrates how coherent diffraction imaging with free-electron lasers can visualize ultrafast electronic and structural changes in xenon clusters, revealing transient core-shell formations during nanoplasma development.

Contribution

It introduces a resonant scattering method to image ultrafast electron dynamics and transient structures in nanoplasmas using intense EUV pulses.

Findings

Detection of transient core-shell structures in xenon clusters.

Resonant scattering reveals electron dynamics during nanoplasma formation.

Simulations support the experimental observation of ionization-induced refraction changes.

Abstract

We have recorded the coherent diffraction images of individual xenon clusters with intense extreme ultraviolet pulses to elucidate the influence of light-induced electronic changes on the diffraction pattern. Using the FLASH free-electron laser we tuned the wavelength to specific xenon atomic and ionic resonances. The data show the emergence of a transient core-shell structure within the otherwise homogeneous sample. Simulations indicate that ionization and nanoplasma formation result in a cluster shell with strongly altered refraction. The presented resonant scattering approach enables imaging of ultrafast electron dynamics on their natural time scale.