Effect of incoming radiation on the non-LTE spectrum of Xe at Te = 100 eV

TL;DR

This study investigates how diluted incoming radiation influences the non-LTE spectral properties of xenon at 100 eV, revealing that even minimal radiation significantly alters ionization and spectral line ratios.

Contribution

It provides a detailed atomic model and simulations showing the impact of radiation field parameters on xenon's spectral characteristics at high temperature.

Findings

Dilution D = 0.01 changes average charge state Z* by over 1.5

Different Tr and D combinations can produce similar Z* but different line ratios

Radiation field shape and atomic structure interplay affects spectral line ratios

Abstract

The effect of a diluted Planckian radiation field on a Xe gas at the electron temperature of 100 eV is investigated within the framework of a Collisional Radiative Model, using the HULLAC code. The atomic model spans 19 charge states, includes 20 375 configurations and contains more than 2 10^6 levels. We have simulated detailed spectra comprising more than 10^9 transitions with the Mixed UTA model. The radiation temperature Tr is varied from 0 to 1.5 Te. The dilution factor, D, applied to decrease the radiation field, is varied independently from 0 to 3 at fixed Tr = Te. In both cases, the average charge state Z* increases from 15 to 27, but in different ways. It is shown that even a dilution D = 0.01 changes Z* by more than 1.5. Different combinations of Tr and D yielding exactly the same Z*, may give line ratios sufficiently different to be observed. This fact is explained by the interplay of the shape of the radiation field and the atomic structure.