Numerical Simulation of Alfven Solitons Employing Derivative Nonlinear Schroedinger Equation
Y. Nishimura1*
1Institute of Space and Plasma Sciences, National Cheng Kung University, Tainan, Taiwan
* Presenter:Y. Nishimura
Dynamics of Langmuir solitons [coupling between Langmuir waves and ion acoustic waves (IAW)] can be described by Zakharov equations which can be reduced nonlinear Schroedinger equation (NLS) in a static density limit. On the other hand, Alfven solitons (coupling between circularly polarized shear Alfven waves and IAWs) can be described by derivative nonlinear Schroedinger equation (DNLS). Both the solitions play roles in regulating turbulence in laboratory and space plasmas. Existence of the solitons can induce transport in the phase space due to the overlapping of the resonant islands, which then result in generation of high energy particles. Our preliminary numerical analysis on Alfven solitons suggests that Alfven solitons can possibly find their own stable states [S. R. Spangler, Astrophys. J. 299, 122 (1985)] for a beta>1 right circularly polarized, and beta <1 and right circularly polarized Alfven waves. Stability of the nonlinear waves is investigated.

Keywords: Nonlinear Alfven waves, Derivative nonlinear Schroedinger equation, Numerical simulation