Solar wind strahl broadening by self-generated plasma waves

• Autor(a) principal: Pavan, Joel
• Data de Publicação: 2013
• Outros Autores: Figueroa Viñas, Adolfo, Yoon, Peter H., Ziebell, Luiz Fernando, Gaelzer, Rudi
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UFRGS
• Texto Completo: http://hdl.handle.net/10183/109065
• topic: Ondas de Langmuir em plasmas; Plasmas astrofisicos; Vento solar; Ondas eletrostáticas em plasmas; Diffusion; Instabilities; Interplanetary medium; Plasmas; Solar wind; Waves

This Letter reports on the results of numerical simulations which may provide a possible explanation for the strahl broadening during quiet solar conditions. The relevant processes involved in the broadening are due to kinetic quasi-linear wave–particle interaction. Making use of static analytical electron distribution in an inhomogeneous field, it is found that self-generated electrostatic waves at the plasma frequency, i.e., Langmuir waves, are capable of scattering the strahl component, resulting in energy and pitch-angle diffusion that broadens its velocity distribution significantly. The present theoretical results provide an alternative or complementary explanation to the usual whistler diffusion scenario, suggesting that self-induced electrostatic waves at the plasma frequency might play a key role in broadening the solar wind strahl during quiet solar conditions.