Parametric study of the generation of electromagnetic waves in an active experiment with electron beams

Active experiments in the ionosphere aim to artificially and significantly modify the space and/or ionospheric environment over large spatial scales. A typical goal of such experiment would be to deplete high energy particles from selected orbits, using, for example, physical processes based on wave-particle interactions with artificially emitted electromagnetic waves. In this work, we study electromagnetic waves generated by an electron beam in the ionosphere. We use the Beam Plasma Interaction Experiment (Beam PIE) as reference, with a typical altitude of ~500 km and a ~15 keV electron pulsed beam emitted parallel to the magnetic field. We rely on the heavily parallelized SMILEI code to perform a parametric study with fully kinetic Particle-In-Cell simulations of such beams. Such study is only made possible thanks to simulation cost reduction through a dimension reduction to a 2D problem with cylindrical symmetry. Varying both the main parameters of the beam (beam density, frequency, length, etc.) and of the ambient environment (magnetic field strength and cold plasma density), we investigate the impact of those parameters on the electromagnetic wave generation mechanism and the wave’s properties. We especially look into the dependance of the wave’s energy distribution and power to the initial beam properties.