Theoretical Studies of L-shell X-ray Line Polarization and M-shell X-ray Spectroscopic Emission from Highly Ionized Xenon Ions
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Authors
Gill, Amandeep Kaur
Issue Date
2023
Type
Dissertation
Language
Keywords
HED Plasmas , Non-LTE Modeling , X-ray Line Polarization
Alternative Title
Abstract
The field of high-energy-density (HED) physics has important applications, such as inertial confinement fusion and the development of intense radiation sources. X-ray plasma spectroscopy and spectropolarimetry are integral to the study of HED plasmas. Comparison of x-ray line emission spectra to non-local thermodynamic equilibrium (non-LTE) modeling and inclusion of non-thermal effects provides insights to laboratory-produced plasmas and underlying atomic processes. Xenon (Xe) radiation has been extensively studied for lithography applications and Xe gas-puffs have proven to be efficient radiation sources. Consequently, a new M-shell Xe non-LTE model was constructed using atomic database calculations with the Flexible Atomic Code (FAC) and is presented in this dissertation. From this new model, plasma parameter-sensitive synthetic spectra are presented and benchmarked with two different HED plasma experiments. Notable results include a robust description of emission lines arising from ionization stages Co-like to Ar-like Xe that are identified in both experiments, the first is a laser-irradiated gas-puff and the second is a reversed polarity gas-puff Z-pinch. The difference between spectra was mostly caused by non-thermal effects manifesting in the Z-pinch as characteristic L-shell Xe lines. HED plasmas are able to produce beams of non-Maxwellian electrons that may cause partially polarized x-ray line emission. Expanding upon this work, comprehensive theoretical study of L-shell Xe and the effects of x-ray line polarization on dielectronic satellite lines is accomplished. X-ray line degree of polarization and polarization-dependent spectra of Na-like Xe influenced by electron beams were calculated using different formalism and methods. Accuracy of FAC atomic data was explored. Future development of current M-shell Xe model and L-shell Xe polarization work will focus on applications to various HED plasma experiments with Xe as dopants or uniform targets.