title: Fluid nonlinear frequency shift of nonlinear ion acoustic waves in multi-ion species plasmas in the small wave number region.
abstract: The properties of the nonlinear frequency shift (NFS), especially the fluid NFS from the harmonic generation of the ion-acoustic wave (IAW) in multi-ion species plasmas, have been researched by Vlasov simulation. Pictures of the nonlinear frequency shift from harmonic generation and particle trapping are shown to explain the mechanism of NFS qualitatively. The theoretical model of the fluid NFS from harmonic generation in multi-ion species plasmas is given, and the results of Vlasov simulation are consistent with the theoretical result of multi-ion species plasmas. When the wave number kλ_{De} is small, such as kλ_{De}=0.1, the fluid NFS dominates in the total NFS and will reach as large as nearly 15% when the wave amplitude |eϕ/T_{e}|∼0.1, which indicates that in the condition of small kλ_{De}, the fluid NFS dominates in the saturation of stimulated Brillouin scattering, especially when the nonlinear IAW amplitude is large.
authors.affiliation: HEDPS, Center for Applied Physics and Technology, Peking University, Beijing 100871, China.
authors.forename: Q S
authors.initials: QS
authors.lastname: Feng
authors.affiliation: HEDPS, Center for Applied Physics and Technology, Peking University, Beijing 100871, China.|School of Physics and Electronics, Hunan University, Changsha 410082, People's Republic of China.
authors.forename: C Z
authors.initials: CZ
authors.lastname: Xiao
authors.affiliation: HEDPS, Center for Applied Physics and Technology, Peking University, Beijing 100871, China.
authors.forename: Q
authors.initials: Q
authors.lastname: Wang
authors.affiliation: HEDPS, Center for Applied Physics and Technology, Peking University, Beijing 100871, China.|Institute of Applied Physics and Computational Mathematics, Beijing, 100094, China.|Collaborative Innovation Center of IFSA (CICIFSA), Shanghai Jiao Tong University, Shanghai, 200240, China.
authors.forename: C Y
authors.initials: CY
authors.lastname: Zheng
authors.affiliation: HEDPS, Center for Applied Physics and Technology, Peking University, Beijing 100871, China.|Institute of Applied Physics and Computational Mathematics, Beijing, 100094, China.
authors.forename: Z J
authors.initials: ZJ
authors.lastname: Liu
authors.affiliation: HEDPS, Center for Applied Physics and Technology, Peking University, Beijing 100871, China.|Institute of Applied Physics and Computational Mathematics, Beijing, 100094, China.|Collaborative Innovation Center of IFSA (CICIFSA), Shanghai Jiao Tong University, Shanghai, 200240, China.
authors.forename: L H
authors.initials: LH
authors.lastname: Cao
authors.affiliation: HEDPS, Center for Applied Physics and Technology, Peking University, Beijing 100871, China.|Institute of Applied Physics and Computational Mathematics, Beijing, 100094, China.|Collaborative Innovation Center of IFSA (CICIFSA), Shanghai Jiao Tong University, Shanghai, 200240, China.
authors.forename: X T
authors.initials: XT
authors.lastname: He