Riconda, C.Heron, A.Pesme, D.Huller, S.Tikhonchuk, V. T.Detering, F.2015-11-062015-11-061070-664Xhttp://hdl.handle.net/1885/16394The role of ion and electron kinetic effects is investigated in the context of the nonlinear saturation of a driven ion acoustic wave(IAW) and its parametric decay into subharmonics. The simulations are carried out with a full–particle-in-cell (PIC) code, in which both ions and electrons are treated kinetically. The full-PIC results are compared with those obtained from a hybrid-PIC code (kinetic ions and Boltzmann electrons). It is found that the largest differences between the two kinds of simulations take place when the IAW is driven above the ion wave-breaking limit. In such a case of a strong drive, the hybrid-PIC simulations lead to a Berstein-Greene-Kruskal-like nonlinear IAW of a large amplitude, while in the full-PIC the IAW amplitude decays to a small level after a transient stage. The electron velocity distribution function is significantly flattened in the domain of small electron velocities. As a result the nonlinear frequency shift due to the electron kinetic effects compensates partly the nonlinear frequency shift due to the ion kinetic effects, allowing then for the parametric decay of the driven IAW into subharmonics. These observations lead to the conclusion that electron kinetic effects become important whenever the nonlinear effects come into play.http://www.sherpa.ac.uk/romeo/issn/1070-664X..."Publishers version/PDF may be used on author's personal website, institutional website or institutional repository" from SHERPA/RoMEO site (as at 6/11/15). Copyright 2005 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Physics of Plasmas and may be found at https://doi.org/10.1063/1.2132272Keywords: Computer simulation; Electrons; Functions; Harmonic analysis; Parameter estimation; Velocity; Electron velocities; Kinetic effects; Nonlinear effects; Subharmonics; Ion acoustic waves2005-11-2210.1063/1.21322722015-12-08