Ts. Perry et al., ABSORPTION EXPERIMENTS ON X-RAY-HEATED MID-Z CONSTRAINED SAMPLES, Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics, 54(5), 1996, pp. 5617-5631
Results of a niobium absorption experiment are presented that represen
t a major step in the development of techniques necessary for the quan
titative characterization of hot, dense matter. The general requiremen
ts for performing quantitative analyses of absorption spectra are disc
ussed. Hydrodynamic simulations are used to illustrate the behavior of
tamped x-ray-heated matter and to indicate potential two-dimensional
problems inherent in the technique. The absorption spectrum of a low-Z
material, in this case aluminum, mixed with niobium provides a temper
ature diagnostic, which together with radiography as a density diagnos
tic fully characterizes the sample. A discussion is presented of opaci
ty calculations and a comparison to the measurements is given that ill
ustrates the need for experiments to provide a critical test of theory
. The experimental technique is placed in context with a review of pre
vious measurements using absorption spectroscopy to probe hot, dense m
atter. It is shown that the overall experimental concepts, although un
derstood, were not always achieved in previous experiments.