Calculating Opacity in Hot, Dense Matter using Second-Order Electron-Photon and Two-Photon Transitions to Approximate Line Broadening

TL;DR

This paper proposes a novel method for calculating opacity in hot, dense plasma by using second-order electron-photon and two-photon transitions, aiming to improve line broadening models beyond traditional Lorentzian approximations.

Contribution

It introduces a new approach to approximate line broadening in plasma opacity calculations using second-order transitions, extending beyond the line centre.

Findings

Preliminary results indicate increased opacity away from absorption lines.

The approach offers a potential improvement over existing models for plasma opacity.

It provides a theoretical basis for more accurate opacity calculations in dense matter.

Abstract

Calculations of the opacity of hot, dense matter require models for plasma line broadening. However, the most general theories are too complex to calculate directly and some approximation is inevitably required. The most widely-used approaches focus on the line centre, where a Lorentzian shape is obtained. Here, we demonstrate that in the opposite limit, far from the line centre, the opacity can be expressed in terms of second-order transitions, such as electron-photon and two-photon processes. We suggest that this insight could form the basis for a new approach to improve calculations of opacity in hot, dense matter. Preliminary calculations suggest that this approach could yield increased opacity away from absorption lines.