The effect of electron holes on cyclotron maser emission driven by horseshoe distributions

TL;DR

This study quantitatively examines how electron holes influence electron-cyclotron maser emission driven by horseshoe distributions, revealing significant growth rate enhancements and potential explanations for fine radiation structures.

Contribution

It introduces an integrated distribution function including electron holes to analyze their impact on ECM, a novel approach in this context.

Findings

Electron holes can increase ECM growth rates by 2-3 times.

Electron holes may explain narrowband radiation fine structures.

The effect is significant in a very narrow waveband.

Abstract

This Brief Communication presents a quantitative investigation for the effect of electron holes on electron-cyclotron maser (ECM) driven by horseshoe distributions. The investigation is based on an integrated distribution function for the horseshoe distributions with electron holes. Results show that the presence of electron holes can significantly enhance the ECM growth rate by 2-3 times in a very narrow waveband. The present study suggests that these electron holes probably are responsible for some fine structures of radiations, such as narrowband events in auroral kilometric radiation and solar microwave spikes.