Comment on "Electron impact excitation and ionization cross section of tungsten ions, W${}^{44+}$" by El-Maaref et al. [J. Quant. Spectrosc. Radiat. Transfer 2019, 224:147]

Abstract

In a recent paper, El-Maaref et al. [J. Quant. Spectrosc. Radiat. Transfer 2019, 224:147] have reported atomic data for Zn-like W~XLV. Their results are mainly for energy levels, radiative rates, collision strengths ($\Omega$) for electron impact excitation, and cross sections for ionization, but for only for a few levels/transitions, and in a very limited range of energy. For the calculations of $\Omega$ they have adopted the DARC code. In this comment, through our independent calculations, we demonstrate that their results for $\Omega$ are highly underestimated by over two orders of magnitude, and hence are totally unreliable.

4pp including 1 Table and 2 Figures will soon appear in JQSRT (2019)