Anisotropic LMN dielectronic resonances from ratios of magnetic-dipole lines

TL;DR

This study detects and analyzes anisotropic LMN dielectronic resonances in highly-charged tungsten ions using EUV magnetic-dipole line ratios, revealing the importance of anisotropy effects in electron beam ion trap measurements.

Contribution

It introduces a method to observe anisotropic dielectronic resonances in highly-charged ions through magnetic-dipole line ratios, emphasizing anisotropy effects in modeling.

Findings

Detection of multi-keV LMN dielectronic resonances in tungsten ions.

Confirmation of anisotropy effects due to electron beam propagation.

Simultaneous registration of resonances from multiple ions.

Abstract

Signatures of multi-keV LMN dielectronic resonances in highly-charged 3d^n ions of tungsten were detected in the intensity ratios of extreme-ultraviolet magnetic-dipole lines within ground configurations. The measurements were performed with an electron beam ion trap at beam energies of about 6 keV. Large-scale collisional-radiative modeling incorporating magnetic sublevels of autoionizing levels showed the significance of anisotropy effects due to the monodirectional propagation of the electron beam. The observation method allows simultaneous resolved registration of dielectronic resonances from several ions.