Kinetic equations for Stark line shapes

TL;DR

This paper revisits the kinetic modeling of Stark line shapes in plasma spectroscopy, incorporating triple correlations to improve accuracy and demonstrate their impact on line width estimates.

Contribution

It introduces a generalized approach to include triple correlations in kinetic equations for Stark line shape modeling, improving upon previous simplified collisional models.

Findings

Neglecting triple correlations can overestimate line widths.

Including triple correlations refines Stark line shape predictions.

Application to hydrogen lines shows significant differences in diagnostics.

Abstract

The BBGKY formalism is revisited in the framework of plasma spectroscopy. We address the issue of Stark line shape modeling by using kinetic transport equations. In the most simplified treatment of these equations, triple correlations between an emitter and the perturbing charged particles are neglected and a collisional description of Stark effect is obtained. Here we relax this assumption and retain triple correlations using a generalization of the Kirkwood truncature hypothesis to quantum operator. An application to hydrogen lines is done in the context of plasma diagnostic, and indicates that the neglect of triple correlations can lead to a significant overestimate of the line width.