Z-pinches have been intensively studied for their applications to high energy density (HED) physics, x-ray sources, astrophysics, and inertial confinement fusion. Alumel (mostly Ni) double planar wire array (DPWA) Z-pinch experiments were performed on the Zebra generator at the enhanced current of 1.6 MA with an advanced setup of diagnostics to measure the temporal evolution of x-ray radiation from plasmas. The implementation of two time-gated spectrometers which recorded hard and soft x-ray radiation allowed for simultaneous studies of K-shell and L-shell radiating plasmas, respectively, in a single experiment. Two almost identical DPWA experiments established a wide observation window around the main x-ray burst. Overall, time-gated plasma spectroscopy provided more information on temporal evolution of 'hot' and 'cold' K-shell radiating plasmas compared to slowly evolving L-shell radiating plasma. In addition, new spectral features such as from hollow ions were observed and studied using the time-gated K-shell plasma spectroscopy, which is important for further investigation of exotic ion states in HED plasmas.
This paper investigates the use of Z-pinches to study high-energy density plasmas, focusing on the simultaneous measurement of K-shell and L-shell x-ray radiation. The experiments provided insights into the temporal evolution of 'hot' and 'cold' plasmas, as well as the observation of new spectral features like hollow ions, which are important for understanding exotic ion states in high-energy density plasmas.