Recombination dynamics of clusters in intense extreme-ultraviolet and near-infrared fields

Bernd Schütte,Thomas Fennel,Mathias Arbeiter,Marc J J Vrakking,Arnaud Rouzée,Tim Oelze,Maria Krikunova

doi:10.1088/1367-2630/17/3/033043

Abstract

We investigate electron-ion recombination processes in clusters exposed to intense extreme-ultraviolet (XUV) or near-infrared (NIR) pulses. Using the technique of reionization of excited atoms from recombination (REAR), recently introduced in Schütte et al (2014 Phys. Rev. Lett. 112 253401), a large population of excited atoms, which are formed in the nanoplasma during cluster expansion, is identified under both ionization conditions. For intense XUV ionization of clusters, we find that the significance of recombination increases for increasing cluster sizes. In addition, larger fragments are strongly affected by recombination as well, as shown for the case of dimers. We demonstrate that for mixed Ar–Xe clusters exposed to intense NIR pulses, excited atoms and ions are preferentially formed in the Xe core. As a result of electron-ion recombination, higher charge states of Xe are efficiently suppressed, leading to an overall reduced expansion speed of the cluster core in comparison to the shell.

Highlights

March 2015We investigate electron-ion recombination processes in clusters exposed to intense extremeauthor(s) and the title of the work, journal citation ultraviolet (XUV) or near-infrared (NIR) pulses
The ionization processes in rare-gas clusters interacting with intense light pulses exhibit significant differences depending on the laser wavelengths
Our studies reveal that charge recombination preferentially takes place in the Xe core of the clusters, similar to the results on clusters ionized by intense XUV pulses

Summary

March 2015

We investigate electron-ion recombination processes in clusters exposed to intense extremeauthor(s) and the title of the work, journal citation ultraviolet (XUV) or near-infrared (NIR) pulses. From recombination (REAR), recently introduced in Schütte et al 112 253401), a large population of excited atoms, which are formed in the nanoplasma during cluster expansion, is identified under both ionization conditions. For intense XUV ionization of clusters, we find that the significance of recombination increases for increasing cluster sizes. We demonstrate that for mixed Ar–Xe clusters exposed to intense NIR pulses, excited atoms and ions are preferentially formed in the Xe core. As a result of electron-ion recombination, higher charge states of Xe are efficiently suppressed, leading to an overall reduced expansion speed of the cluster core in comparison to the shell

Introduction

Experimental setup

Electron-ion recombination following intense XUV ionization of clusters

Findings

Summary