Mode transition and nonlinear dynamics in the beam-injected plasma

Summary form only given. The motions of electron beams in a discharge plasma are simulated using the 1-D particle-in-cell code (XPDP1). With appropriate pressures, beam current, beam velocity, and voltages, there is mode transition from the anode glow mode (AGM) to the temperature limited mode (TLM). The transition happens when the ionized ions which make the potential positive fill the entire space. During transition from AGM to TLM, the dynamics show chaotic motions and the current increases to the injected beam current. After the TLM is established, the dynamics of electron current and potential show self oscillation, periodic doubling, or chaos for various electron to ion number ratios, sheath sizes, and bulk potential levels. The higher bulk potential level is, the larger fluctuation amplitude of current is observed. For higher pressures of neutral gas, the dynamics show more chaotic but small amplitude of fluctuation motions.