Semi-analytical Model of Laser Resonance Absorption in Plasmas

TL;DR

This paper introduces a semi-analytical model to describe laser resonance absorption in inhomogeneous plasmas, accurately predicting energy absorption across various density scale lengths by solving Maxwell's equations.

Contribution

The paper presents a new semi-analytical approach to model laser resonance absorption in plasmas, bridging classical approximations and numerical results.

Findings

Model accurately predicts absorbed energy fraction versus incidence angle.

Explains classical high-density results and numerical simulations.

Applicable across a wide range of density scale lengths.

Abstract

When an electromagnetic wave is obliquely incident on an inhomogeneous high density plasma, it will be absorbed resonantly as long as it is polarized in the plane of incidence and has an electric field component along the plasma electron density gradient. This process takes place by linear mode conversion into an electron plasma wave. In this paper, we have considered the resonant absorption of laser light near the critical density of a plasma with linear electron density profile. The behaviour of the electric and magnetic vectors of a laser light propagating through inhomogeneous plasma has been studied by calculating them using Maxwell's equations using a new semi-analytical model. The absorbed fraction of the laser light energy, then, evaluated and plotted versus the angle of incidence. It has been shown that this new model can explain the previous classical approximated results at high density scale lengths as well as the reported numerical results in almost all density scale lengths.