X-ray emission from exotic ions in dense Al pulsed power plasmas*

During the last decade, with the substantial increase in laser pulse intensities and very active research on X-ray Free Electron Lasers, the observation of extreme states of matter became possible using advanced plasma spectroscopy. In particular, the new spectral features that are attributed to x-ray emission from exotic states of matter (KK hollow ions with the empty K shell) attracted a lot of attention. Despite the substantial progress made in modeling such new spectroscopic features from laser-produced plasmas, only a few papers considered hollow ion radiation from Z-pinch plasmas. In search of such exotic spectral features, we have analyzed x-ray data produced with wire arrays and X-pinches on various university-scale Z-pinch generators. Here we present the results of our search for KK hollow ion spectroscopic features from low-atomic-number Z- and X-pinches on university-scale generators based on the analysis of many experiments with alloyed aluminum (Al 95% and Mg 5%) wire loads. We discuss the nonthermal effects in dense pulsed power plasmas that can lead to generation of such exotic ions and preliminary modeling, as well as future work.