Ionization dynamics and x-ray transmission of aluminum plasma at temperature reaching 110 eV.

In this research, ∼0.14-micron-thick aluminum tamped by plastic is heated up to ∼110eV by the x-ray pulse from the Z-pinch-driven dynamic Hohlraum on an 8-MA machine in China. After an ∼6-ns heating stage, higher-energy xrays from an ∼2-ns- long backlight pulse pass through the hot aluminum. The transmission is estimated by comparing the radiation passing through the aluminum sample in one shot with the radiation through only the plastic in another shot, with the x-ray spectra obtained using an elliptically bent concave crystal spectrometer. The transmission reveals features corresponding to x-ray absorption in Li-like and a series of He-like aluminum ions that provide values for its temperature and density. One method involves using a tabulated opacity database, while the other involves analyzing the line shapes and line ratios of the absorption features. The challenges in these measurements are discussed both theoretically and experimentally.