Measurements and radiation transport of emitted and absorbed spectral lines within an expanded, dense aluminum plasma*

Emission and absorption lines have been measured within an expanded, dense aluminum plasma plume produced by electron beam isochoric heating of 100-um-thick aluminum foils. The intense, monochromatic electron beam (20 MeV, 1.45 kA, 80-ns FWHM) deposits approximately 5 J in a sub-1-mm FWHM spot, heating and subsequently expanding the material through the warm dense plasma phase [1]. A spectroscopic-quality radiation transport model [2] has been developed using inputs from a radiation-hydrodynamics code [3] along with the LANL suite of atomic physics codes [4] to provide a complete simulation capability for matching the experimental spectra. The resulting model has been benchmarked by visible interferometer measurements. New simulations predicting the EUV spectrum (< 200 nm) of the dense aluminum plasma plume are presented, along with the design and current status of a grazing-incidence EUV spectrometer that will be deployed to make the experimental measurements. A comparison between aluminum Sesame [5] EOS 3715 and 3720 for the radiation-hydrodynamics model is also discussed.

[1] N. B. Ramey et al., Phys. Plasmas 28, 033301 (2021).

[2] P. Hakel, Comp. Phys. Commun. 207, 415 (2016).

[3] G. B. Zimmerman and W. L. Kruer, Comments Plasma Phys. Controlled Fusion 2, 51 (1975).

[4] C. J. Fontes et al., J. Phys. B 48, 144014 (2015).

[5] SESAME Library, Report No. UCID-118574-82-2 (Lawrence Livermore National Laboratory, 1982).