Computational stutuies of Langmuir solitons and oscillating two stream instabilities

By a Particle-in-Cell simulation, generation of Langmuir solitons \footnote{E. J. Valeo and W. L. Kruer, Phys. Rev. Lett. 33, 750 (1974).} is investigated. Onset of oscillating two stream instability (OTSI) \footnote{K. Nishikawa, J. Phys. Soc. Jpn., 24, 916 (1968).} is observed subsequent to the collapse of the solitons. The saturation mechanism of OTSI is discussed by by estimating the separatrix of resonating islands in the phase space.