High-resolution autoionizing line spectra of Mg ii and Al iii in the 160–260-Å range emitted from a Penning ionization discharge plasma

Spectra of aluminum and magnesium emitted from a Penning ionization discharge have been recorded in the XUV range by 2-m grazing-incidence spectrometer. Autoionizing satellite lines, originating from transitions between core excited levels lying in the continuum and ground or lowest excited states of the Na i-like Al iii and Mg ii, have been classified. Their implication for ionization cross-section estimates and XUV laser research is discussed.