Natural-linewidth measurements of the 3C and 3D soft-x-ray transitions in Ni XIX

TL;DR

This study precisely measured the natural linewidths and oscillator-strength ratio of the 3C and 3D soft-x-ray transitions in Ni XIX ions using synchrotron radiation, confirming previous data and theoretical predictions.

Contribution

First precise measurements of natural linewidths and oscillator-strength ratio for Ni XIX 3C and 3D transitions using high-resolution synchrotron radiation.

Findings

Natural linewidths measured with better than 10% accuracy.

Oscillator-strength ratio f(3C)/f(3D) = 2.51(11).

Results agree with previous experiments and theoretical calculations.

Abstract

We used the monochromatic soft-x-ray beamline P04 at the synchrotron-radiation facility PETRA III to resonantly excite the strongest $2p-3d$ transitions in neon-like Ni XIX ions, $[2p^6]_{J=0} \rightarrow [(2p^5)_{1/2}\,3d_{3/2}]_{J=1}$ and $[2p^6]_{J=0} \rightarrow [(2p^5)_{3/2}\,3d_{5/2}]_{J=1}$, respectively dubbed 3C and 3D, achieving a resolving power of 15\,000 and signal-to-background ratio of 30. We obtain their natural linewidths, with an accuracy of better than 10\%, as well as the oscillator-strength ratio $f(3C)/f(3D)$ = 2.51(11) from analysis of the resonant fluorescence spectra. These results agree with those of previous experiments, earlier predictions, and our own advanced calculations.