Particle-in-cell simulations of beam-driven electrostatic waves in a plasma

Using a particle-in-cell simulation, the characteristics of electrostatic waves are investigated in a three-electron component plasma including an electron beam. A Maxwellian distribution is used to describe the electron velocities. Three electrostatic modes are excited, namely electron plasma, electron acoustic, and beam-driven waves. These modes have a broad frequency spectrum and have been associated with intense broadband electrostatic noise observed in the Earth's auroral zone. The simulation results compare well with analytical dispersion and growth rate relations. This agreement serves to validate the simulation technique. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.3695402]