Fig. 1. Experimental setup for opacity measurements: (a) arrangement of Hohlraum, sample, backlighter, and diagnostics; (b) geometry of crystal spectrometers; (c) the view angles of FXRDs simulated by IRAD3D.

Fig. 2. Time evolution of radiation flux recorded by the three FXRDs at different view angles in shot N20087: (a) raw radiation flux; (b) contributions of Hohlraum and backlighter.

Fig. 3. (a) Time evolution and (b) peak values of radiation temperature reconstructed from three FXRDs at different view angles.

Fig. 4. (a) Raw images and (b) cross sections of backlighter (shot N20100) and absorption (shot N20087) spectra in the Sc transmission measurements.

Fig. 5. Measured Sc transmission spectrum obtained by comparing the absorption of the Mo/Sc mixture sample in shot N20087 and of the backlighter in shot N20010, and the spectra calculated with a DTA model at electron temperatures of 131, 122, and 140 eV and a density of 0.006 g/cm³.

Fig. 6. Radiation temperature felt by the sample at 1.7 ns simulated by IRAD3D.

Fig. 7. Time evolution of electron temperature and density in (a) Sc and (b) Mo plasmas predicted by a hydrodynamic simulation by MULTI, along with the radiation temperature (dash-dotted line) used in the simulation.

Fig. 8. Experimental Mo transmission measurement in shot N20085: (a) raw image; (b) cross sections of backlighter and absorption spectra; (c) cross section of transmission spectrum.

Fig. 9. Charge state fractions in the Mo plasma at T_e = 132, 138, and 144 eV and ρ = 0.009 g/cm³.

Fig. 10. Contributions of Mo ions to the total transmission spectrum. An artificial optical depth was used in the calculation to enable a illustrative comparison with the experimental spectrum.

Fig. 11. Transmissions of Mo ions calculated by the DCA model with different configurations.

Fig. 12. Comparison between Mo L-shell transmission spectra obtained from experimental measurements and from DCA model calculations at different electron temperatures.