Validating Continuum Lowering Models via Multi-Wavelength Measurements of Integrated X-ray Emission

TL;DR

This paper introduces a novel method for validating continuum lowering models in dense plasmas using total emission intensity measurements across various wavelengths, bypassing the need for detailed spectral line identification.

Contribution

It presents a new approach that validates continuum lowering models solely through integrated emission data, applicable even when spectral signatures are overlapping or indistinct.

Findings

Validated models using published Al data

Applied method to Fe plasmas with overlapping emissions

Demonstrated effectiveness without spectral line identification

Abstract

X-ray emission spectroscopy is a well-established technique used to study continuum lowering in dense plasmas. It relies on accurate atomic physics models to robustly reproduce high-resolution emission spectra, and depends on our ability to identify spectroscopic signatures such as emission lines or ionization edges of individual charge states within the plasma. Here we describe a method that forgoes these requirements, enabling the validation of different continuum lowering models based solely on the total intensity of plasma emission in systems driven by narrow-bandwidth x-ray pulses across a range of wavelengths. The method is tested on published Al spectroscopy data and applied to the new case of solid-density partially-ionized Fe plasmas, where extracting ionization edges directly is precluded by the significant overlap of emission from a wide range of charge states.