Emission phases of implosion sources for x-ray absorption fine structure spectroscopy

At the Laboratory for Laser Energetics' Omega Laser Facility, thin plastic shells were directly driven with similar to 20 kJ resulting in a time-integrated x-ray yield of similar to 10(12) ph/eV/sr at 7 keV. Using temporally, spatially, and spectrally discriminating diagnostics, three x-ray emission phases were identified: corona emission produced by the laser ablation of the shell, core stagnation, and afterglow emission due to the expanding hot material after stagnation. The newly measured corona and afterglow emission phases account for similar to 25% of the total x-ray signal and produce x-ray emission at a different time or larger radius than previously considered. The resulting implications of this additional emission for x-ray absorption fine structure spectroscopy are discussed. Finally, improvements to the laser drive intensity and uniformity produced a factor-of-2 increase in total x-ray emission while decreasing the size of the stagnated core.& nbsp;(C) 2022 Author(s).All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY)license (http://creativecommons.org/licenses/by/4.0/).