Wakefield generation in magnetized plasmas

TL;DR

This paper investigates wakefield generation in magnetized plasmas with electromagnetic pulses perpendicular to the magnetic field, revealing spectrum broadening and increased pulse loss at high cyclotron frequencies through simulations and theoretical modeling.

Contribution

It introduces a set of equations for scalar and vector potentials that explain wakefield behavior in strongly magnetized plasmas, extending previous understanding.

Findings

Wakefield spectrum peaks at inverse skin depth for moderate magnetic fields.

At high cyclotron frequencies, the spectrum broadens significantly.

Pulse loss rate increases markedly when cyclotron frequency exceeds plasma frequency.

Abstract

We consider wakefield generation in plasmas by electromagnetic pulses propagating perpendicular to a strong magnetic field, in the regime where the electron cyclotron frequency is equal to or larger than the plasma frequency. PIC-simulations reveal that for moderate magnetic field strengths previous results are re-produced, and the wakefield wavenumber spectrum has a clear peak at the inverse skin depth. However, when the cyclotron frequency is significantly larger than the plasma frequency, the wakefield spectrum becomes broad-band, and simultaneously the loss rate of the driving pulse is much enhanced. A set of equations for the scalar and vector potentials reproducing these results are derived, using only the assumption of a weakly nonlinear interaction.