%0 Journal Article
%T Vlasov simulation of Langmuir wave packets
%A T. Umeda
%J Nonlinear Processes in Geophysics (NPG)
%D 2007
%I Copernicus Publications
%X Amplitude modulation and packet formation of Langmuir waves are commonly observed during a nonlinear interaction between electron beams and plasmas. In this paper, we briefly review the history of Langmuir wave packets as developed by recent spacecraft observations and computer simulations. New one-dimensional electrostatic Vlasov simulations are performed to study their formation processes. It is found that the formation of Langmuir wave packets involves both an incoherent turbulent process and a coherent nonlinear trapping process. Existence of cold ions does not affect nonlinear processes of the weak-electron-beam instability in which the ion distribution is hardly modified by the excited Langmuir wave packets.
%U http://www.nonlin-processes-geophys.net/14/671/2007/npg-14-671-2007.html