Electron Microburst Energy Dispersion Derived by Test Particle Simulation Code

Electron microbursts, energetic electron precipitation having duration less than 1 sec, have been thought to be generated by chorus wave and electron interactions. While the coincidence of chorus and microburst occurrence supports the wave-particle interaction theory, more crucial evidences have not been observed to explain the origin of microbursts. We think one of the observational evidences could be energy dispersion of microbursts. During chorus waves propagate along magnetic field, the resonance condition should be satisfied at different magnetic latitude for different energy electrons because chorus waves are coherent waves having narrow frequency band and electron microbursts have wide energy range, at least several hundreds KeV. If we observed electron microbursts at low altitude, the arrival time of different energy electrons should make unique energy dispersion structures. In order to observe the energy dispersion, we need a detector having fast time resolution and wide energy range. Our study is focused on defining the time resolution and energy range required to measure microburst energy dispersion. We performed test particles simulation interacting with simple coherent waves like chorus waves. By the wave-particle interaction, energetic electrons (test particles) changed pitch angles and some electrons were detected with energy dispersion at 600 km. We assumed a detector measuring microbursts at the altitude of 600 km. These results provide useful information in designing electron detectors for the future mission.