Particle-in-Cell Simulations of Two-dimensional Bernstein-Greene-Kruskal (BGK) Modes and Electrostatic Structures

Electrostatic structures have been observed in many regions of space plasmas, including the solar wind, the magnetosphere, and the auroral acceleration region. One possible theoretical description of some of these structures is the concept of Bernstein-Greene-Kruskal (BGK) modes, which are exact nonlinear steady-state solutions of the Vlasov-Poisson system of equations in collisionless kinetic theory. We will present latest Particle-in-Cell (PIC) simulations using exact solutions of two-dimensional (2D) BGK modes in a magnetized plasma with finite magnetic field strength [Ng, Bhattacharjee, and Skiff, Phys. Plasmas 13, 055903 (2006)] as initial conditions to study their stability. We will also present simulations using more general initial conditions, which shows that while these are not steady-state solutions, they still keep their overall structures with modulations having frequency of the order of electron cyclotron frequency. This work is supported by a National Science Foundation grant PHY-1004357.