Evaluation of a measure on the quasi-steady state assumption of Collisional Radiative Models via Intrinsic Low Dimensional Manifold Technique

TL;DR

This paper evaluates the validity of quasi-steady state assumptions in Collisional Radiative Models of plasmas using a novel measure inspired by Intrinsic Low Dimensional Manifold techniques, highlighting discrepancies in low energy states.

Contribution

It introduces a new error measure based on local source estimates to assess quasi-steady state assumptions in plasma models, improving classification accuracy.

Findings

Conventional classification may be inaccurate due to local production effects.

The new measure identifies discrepancies in low energy excited states.

The technique is validated on mercury and argon lamps.

Abstract

Collisional and radiative dynamics of a plasma is exposed by so-called Collisional Radiative Models [1] that simplify the chemical kinetics by quasi-steady state assignment on certain types of particles. The assignment is conventionally based on the classification of the plasma species by the ratio of the transport to the local destruction frequencies. We show that the classification is not exact due to the role of the time-dependent local production, and a measure is necessary to confirm the validity of the assignment. The main goal of this study is to evaluate a measure on the quasi-steady state assumptions of these models. Inspired by a chemical reduction technique called Intrinsic Low Dimensional Manifolds [2, 3], an estimate local source is provided at the transport time-scale. This source is a deviation from the quasi-steady state for the particle and its value is assigned as an error of the quasi-steady state assumption. The propagation of this error on the derived quantities is formulated in the Collisional Radiative Models. Based on the error a novel technique is proposed to discriminate the quasi-steady states. The developed analysis is applied to mercury and argon fluorescent lamps separately and the corresponding errors are presented. We observe that the novel and conventional technique agrees for most of the excited levels but disagrees for a few low energy excited states.