A particle-in-cell approach to obliquely propagating electrostatic waves

Abstract

The electron-acoustic and beam-driven modes associated with electron beams have previously been identified and studied numerically. These modes are associated with Broadband Electrostatic Noise found in the Earth's auroral and polar cusp regions. Using a 1-D spatial Particle-in-Cell simulation, the electron-acoustic instability is studied for a magnetized plasma, which includes cool ions, cool electrons and a hot, drifting electron beam. Both the weakly and strongly magnetized regimes with varying wave propagation angle, θ, with respect to the magnetic field are studied. The amplitude and frequency of the electron-acoustic mode are found to decrease with increasing θ. The amplitude of the electron-acoustic mode is found to significantly grow at intermediate wavenumber ranges. It reaches a saturation level at the point, where a plateau forms in the hot electron velocity distribution after which the amplitude of the electron-acoustic mode decays.

Ion-beam/plasma modes in ultradense relativistic quantum plasmas: Dispersion characteristics and beam-driven instability

“…The excitation of electrostatic (ES) nonlinear localized waves [16,17] via ion beam injection into plasma has been studied theoretically, via small-amplitude [18,19] or largeamplitude nonlinear wave phenomenology [20] and also numerically, e.g. via particle-in-cell (PIC) simulations [21][22][23][24][25].…”