Electron plasma wave excitation by a q-Gaussian laser beam and subsequent electron acceleration

Abstract

In this paper, we theoretically study the propagation dynamics of a q-Gaussian laser beam in a plasma by considering the relativistic and ponderomotive nonlinearities. The q-Gaussian laser beam exhibits unique characteristics while interacting with the plasma. The q-Gaussian laser beam redistributes the plasma density in a different way, which affects the laser self-focusing. A comparative study of the self-focusing for Gaussian and q-Gaussian laser beams is reported. The results obtained from numerical analysis reveal a stronger self-focusing of the q-Gaussian laser beam in plasmas, which is desirable to excite a large amplitude plasma wave for electron acceleration by extending the interaction length. We then extended this study to investigate the electron plasma wave excitation by the q-Gaussian laser beam. The electron plasma wave is driven more efficiently by the q-Gaussian laser beam. Our results show that the electron plasma wave field intensity enhances more than twofold for the q-Gaussian laser beam in comparison with the case of a Gaussian laser beam. The electron plasma wave excited by a q-Gaussian beam can accelerate the plasma electrons to higher energies. Numerical results are presented for the established set of laser and plasma parameters.