959623253 GUO A plasma is a collection of fast-moving, charged particles. Although most matters in the universe are of forms of plasmas, the main goal of the plasma study is to control fusion. When collisions among particles are ignored, there are many interesting steady states in a collisionless plasma. The proposer studies their dynamical stability which has potential applications in the plasma control problem. %%% A plasma is a collection of fast-moving, charged particles. Although most matters in the universe are of forms of plasmas, the main goal of the plasma study is to control fusion. When collisions among particles are ignored, there are many interesting steady states in a collisionless plasma. The proposer studies their dynamical stability which has potential applications in the plasma control problem. ***