Evolution of electron beam pulses of short duration in the solar corona

TL;DR

This paper investigates how short-duration electron beam pulses evolve in the solar corona, revealing rapid energy loss and thermalization processes crucial for understanding solar flare radio emissions.

Contribution

It introduces a numerical approach using the Fokker-Planck equation to model electron beam evolution in the corona, highlighting the impact of low energy cut-offs.

Findings

Short electron pulses lose most energy within one second.

Lower energy cut-offs lead to faster thermalization.

Electron beams with different cut-offs exhibit distinct evolution behaviors.

Abstract

Narrowband radio bursts with durations of the order of milliseconds, called spikes, are known to be associated with solar flares. In order to understand the particle beams responsible for the radio spike phenomena, evolution of electron beam pulses injected from a solar flare region into the corona is studied. Numerical integration of the Fokker-Planck (FP) equation is used to follow the evolution of the electron beam pulse. The simulations show that the short duration pulses lose most of their energy within a second of propagation into the corona. Electron beam with a small low energy cut off is thermalised faster than that with a high low energy cut off.