Low-frequency whistler waves excited by relativistic laser pulses

TL;DR

This paper demonstrates through simulations that relativistic laser pulses can excite intense, vortex-like whistler waves in magnetized plasma, revealing a new excitation mechanism with potential applications in fast ignition.

Contribution

It introduces a novel mechanism for exciting relativistic whistler waves using laser pulses in highly magnetized plasma, supported by simulation results and theoretical analysis.

Findings

Whistler waves with vortex-like topology can be excited by relativistic lasers.

Energy transfer from laser to whistler waves exceeds 15%.

Dispersion and polarization match cold-plasma theory.

Abstract

It is shown by multi-dimensional particle-in-cell simulations that intense secondary whistler waves with special vortex-like field topology can be excited by a relativistic laser pulse in the highly magnetized, near-critical density plasma. Such whistler waves with lower frequencies obliquely propagate on both sides of the laser propagation axis. The energy conversion rate from laser to whistler waves can exceed 15%. Their dispersion relations and field polarization properties can be well explained by the linear cold-plasma model. The present work presents a new excitation mechanism of whistler modes extending to the relativistic regime and could also be applied in magnetically assisted fast ignition.