Scattering of ultrastrong electromagnetic waves by magnetized particles

TL;DR

This paper investigates how ultrastrong electromagnetic waves interact with magnetized particles, revealing that waves with amplitudes exceeding the background magnetic field can rapidly energize particles, leading to significant scattering and high-energy emissions relevant to astrophysical phenomena.

Contribution

It demonstrates that ultrastrong waves can pump energy into particles via resonance, causing large scattering cross sections and high-energy emissions, impacting models of neutron star magnetospheres.

Findings

Waves with E_0 > B_bg pump particle energy rapidly.

Particles reach radiation reaction limit quickly.

Wave scattering cross section becomes very large.

Abstract

Observations of powerful radio waves from neutron star magnetospheres raise the question of how strong waves interact with particles in a strong background magnetic field $B_{bg}$. This problem is examined by solving the particle motion in the wave. Remarkably, waves with amplitudes $E_0>B_{bg}$ pump particle energy via repeating resonance events, quickly reaching the radiation reaction limit. As a result, the wave is scattered with a huge cross section. This fact has implications for models of fast radio bursts and magnetars. Particles accelerated in the wave emit gamma-rays, which can trigger an $e^\pm$ avalanche and, instead of silent escape, the wave will produce X-ray fireworks.