Electron Acceletaion by Laser Driven Electron Plasma Wave in Plasma with Density Ramp: Cosh Gaussian Laser Beam

Abstract

Abstract This paper presents a theoretical investigation into the nonlinear propagation of a Cosh-Gaussian (ChG) laser beam through plasma with axial inhomogeneity. The study takes into consideration the relativistic mass nonlinearity of plasma electrons in response to the laser beam. Additionally, the research explores the influence of self-focusing on the excitation of electron plasma waves (EPWs). The analysis employs variational theory to derive semi-analytical solutions for the nonlinear wave equations governing the laser beam and EPWs. Furthermore, the study examines the acceleration of electrons trapped within the excited EPWs. The results obtained from numerical analysis indicate a more pronounced self-focusing effect of the Cosh-Gaussian laser beam when optimal values of the decentered parameter are utilized. This finding is beneficial for generating high-amplitude EPWs, enabling electron acceleration by extending the interaction length.