Revisiting N$_2$-N$_2$ collisional linewidth models for S-branch rotational Raman scattering

TL;DR

This study evaluates and compares two prevalent Raman linewidth models, MEG and ECS, by fitting their parameters to experimental data and analyzing their effectiveness in modeling N$_2$-N$_2$ collisional linewidths.

Contribution

It provides a critical assessment of existing linewidth models and offers fitted parameters based on experimental data, highlighting differences with previous literature.

Findings

Fitted parameters for MEG and ECS models to experimental linewidths

Comparison reveals differences with previously published parameters

Discussion of model assumptions and applicability

Abstract

This paper presents an evaluation of two commonly accepted Raman linewidth models typically used to fit CARS model parameters to data; the Modified Exponential Gap (MEG) and the Energy Corrected Sudden (ECS) models. The adjustable parameters in each model have been fit to published experimental linewidths, and comparisons are made to the various publications that have already provided similar adjustable constants. The approaches presented in the literature are discussed as are differences with the findings presented here.