Speaker
Description
Electron beams accelerated by solar flares and nanoflares are believed to be responsible for several types of solar radio bursts observed in the corona and interplanetary medium, including flare-associated coronal Type U and J and interplanetary Type III radio bursts, and nanoflare-associated weak coronal type III bursts. The characteristic of these radio bursts is their frequency is consistent with the local electron plasma frequency. However, how electron two-stream instability driven by electron beams produces coherent emission with a duration of several orders of magnitude longer than the linear saturation time is a long-standing puzzle. Recently Che, Goldstein,Diamond and Sagdeev proposed that continuous plasma coherent emission is maintained by repetitive Langmuir collapse. The study of coherent radio emission provides a powerful tool to probe the plasma environment of solar corona and the mechanism of acceleration and energetic particle propagation.I will present this mechanism and the new features that can be observed by spacecrafts and ground based telescope.
