Auroral kilometric radiation and electron pairing

TL;DR

This paper proposes that electron pairing near mirror points in the auroral region could drive the electron cyclotron maser instability, explaining fine structures in auroral kilometric radiation.

Contribution

It introduces a novel mechanism involving electron pairing to explain auroral kilometric radiation fine structures, using a simplified gyrotron model and Dirac distribution.

Findings

Estimated bandwidth and frequency drift match observations.

Mechanism predicts specific spatial locations for radiation.

Model suggests electron pairing influences auroral radio emissions.

Abstract

We suggest that pairing of bouncing medium-energy electrons in the auroral upward current region close to the mirror points may play a role in driving the electron cyclotron maser instability to generate an escaping narrow band fine structure in the auroral kilometric radiation. We treat this mechanism in the gyrotron approximation, for simplicity using the extreme case of a weakly relativistic Dirac distribution instead the more realistic anisotropic J\"uttner distribution. Promising estimates of bandwidth, frequency drift and spatial location are given.