X-ray and extreme-ultraviolet spectra from collisions of Ar$^{18+}$ and O$^{8+}$ ions with neutrals

TL;DR

This study measures K-shell x-ray and extreme-ultraviolet spectra from charge exchange collisions of highly charged argon and oxygen ions with neutrals, analyzing quantum states and comparing with theoretical models.

Contribution

It provides new experimental spectra and quantum state resolution for ion-neutral charge exchange, and evaluates the accuracy of existing theoretical models.

Findings

Measured K-shell x-ray emission from argon ions with various neutrals.

Resolved principal quantum numbers in EUV spectra from oxygen ions.

Identified discrepancies between measurements and multichannel Landau-Zener model predictions.

Abstract

We present measurements of K-shell x-ray emission following charge exchange of fully ionized argon with various neutral gaseous targets at small collision energies inside an electron beam ion trap. We also resolve the principal quantum number of electron capture in extreme-ultraviolet spectra from initially bare and hydrogen-like oxygen ions held in the same trap. We analyze discrepancies between these as well as previous measurements with theoretical models based on the multichannel Landau-Zener approach.