Accuracy of K-shell spectra modeling in high-density plasmas

Area of Science:

• Atomic physics
• Plasma spectroscopy
• Astrophysical plasma modeling

Background:

• Helium-like and lithium-like argon K-shell spectra are essential for plasma diagnostics.
• Dielectronic satellites influence Stark-broadened line profiles in high-density plasmas.

Purpose of the Study:

• To present spectroscopic measurements of argon emission for testing plasma spectroscopic K-shell models.
• To investigate the kinetics modeling of helium-beta and its associated lithium-like satellites.
• To compare experimental data with theoretical predictions for satellite line intensities.

Main Methods:

• Spectroscopic measurements of helium-like and lithium-like argon emission.
• Thomson scattering diagnostics on gas bag targets to determine plasma parameters.
• Experiments conducted in gas bag plasmas at densities of (0.6-1.1)x10^21 cm^-3.
• Independent electron temperature determination using ultraviolet Thomson scattering.

Main Results:

• Measured line radiation in the He-beta wavelength region.
• Observed lithium-like dielectronic satellites on the red wing of the He-beta line.
• Good agreement between satellite intensities and kinetics modeling for dielectronic capture.
• Discrepancies noted for inner-shell collisional excited transitions.

Conclusions:

• The study provides critical tests of plasma spectroscopic K-shell models using argon emission data.
• Kinetics modeling shows good agreement for satellites populated by dielectronic capture.
• Discrepancies in modeling inner-shell collisional excited transitions require further investigation.