Plasma emission by counter-streaming electron beams

• Main Author: Ziebell, Luiz Fernando
• Publication Date: 2016
• Other Authors: Petruzzellis, Larissa Teixeira, Yoon, Peter H., Gaelzer, Rudi, Pavan, Joel
• Format: Article
• Language: eng
• Source: Repositório Institucional da UFRGS
• Download full: http://hdl.handle.net/10183/141540
• topic: Vento solar; Turbulência em plasmas; Plasmas; Radiation mechanisms: non-thermal; Solar wind; Sun: radio radiation; Turbulence; Waves

The radiation emission mechanism responsible for both type-II and type-III solar radio bursts is commonly accepted as plasma emission. Recently Ganse et al. suggested that type-II radio bursts may be enhanced when the electron foreshock geometry of a coronal mass ejection contains a double hump structure. They reasoned that the counter-streaming electron beams that exist between the double shocks may enhance the nonlinear coalescence interaction, thereby giving rise to more efficient generation of radiation. Ganse et al. employed a particle-in-cell simulation to study such a scenario. The present paper revisits the same problem with EM weak turbulence theory, and show that the fundamental (F) emission is not greatly affected by the presence of counter-streaming beams, but the harmonic (H) emission becomes somewhat more effective when the two beams are present. The present finding is thus complementary to the work by Ganse et al.