Simulation Study of Plasma Emission in Beam-Plasma Interactions

Abstract

A two-dimensional electromagnetic particle-in-cell simulation of the beam-plasma interaction process is carried out to study the electromagnetic radiation at the plasma frequency and its second harmonic. In the simulation, a homogeneous plasma background with a periodic boundary condition is assumed. Electromagnetic radiation at the plasma frequency and its higher harmonics are widely believed to be responsible for solar type-II and type-III radio bursts. Traditional theory based upon weak turbulence of three-wave and nonlinear wave-particle interaction processes predicts radiation emission primarily at the fundamental and second harmonic of the plasma frequency. Electrostatic modes and electromagnetic radiation corresponding to this expectation at the fundamental and the second harmonics plasma frequencies are found. The radiation patterns of the fundamental and second harmonic electromagnetic modes are examined in detail.