A vacuum double-crystal spectrometer for reference-free highly charged ions X-ray spectroscopy

TL;DR

This paper introduces a vacuum double-crystal spectrometer coupled with an electron-cyclotron resonance ion source for highly charged ions, achieving high-precision X-ray measurements and detailed spectral analysis.

Contribution

The paper presents a novel spectrometer design and an ab initio simulation code that accurately reproduces experimental spectra of highly charged ions.

Findings

Achieved measurement accuracy of a few parts per million.

Successfully measured X-ray transitions in Ar$^{14+}$, Ar$^{15+}$, and Ar$^{16+}.

Developed a simulation code that reproduces spectra with unprecedented accuracy.

Abstract

We have built a vacuum double crystal spectrometer, which coupled to an electron-cyclotron resonance ion source, allows to measure low-energy x-ray transitions in highly-charged ions with accuracies of the order of a few parts per million. We describe in detail the instrument and its performances. Furthermore, we present a few spectra of transitions in Ar$^{14+}$, Ar$^{15+}$ and Ar$^{16+}$. We have developed an ab initio simulation code that allows us to obtain accurate line profiles. It can reproduce experimental spectra with unprecedented accuracy. The quality of the profiles allows the direct determination of line width.