Investigation of Wave Excitation by Conventional and Parametric Antennas in the Ionospheric Plasma Using Three-Dimensional Particle-in-Cell Simulations

Abstract:

Conventional antennas immersed in a cold, magnetized plasma (CMP) and operating in the very low frequency (VLF) range (e.g. loop and dipole antennas) excite plasma waves that are predominantly electrostatic. For example, loop antennas excited in the frequency range ω_LH < ω < ω_ce (where ω_LH and ω_ce are the lower hybrid and electron cyclotron frequencies) produce electrostatic lower oblique resonance (LOR) waves. Likewise a dipole antenna excited in the frequency range ω_ci < Ω < ω_LH (where ω_ci is the ion cyclotron frequency) produce electrostatic ion acoustic (IA) type density perturbations. The goal of our research is to increase power radiated into the electromagnetic part of the VLF wave spectrum, specifically into electromagnetic Whistler waves. These waves are generated in a CMP due to a nonlinear parametric coupling of the strong quasi-electrostatic electric fields from the loop antenna and the density perturbations from the dipole antenna. Therefore, a parametric antenna is made by parametrically coupling these two waves. Because EM Whistler waves are effective sources of pitch angle diffusion, one application of a parametric antenna includes radiation belt remediation in Earth’s space environment. In this poster we show electric field patterns from the loop and dipole antennas and the EM spectrum excited due to the parametric interaction.