Numerical Design Tool for Space-Borne, Plasma-Coupled VLF Antenna Systems

Relativistic electrons trapped by Earth’s magnetic field pose a threat to spacecraft in low Earth orbit (LEO). High-power, very low frequency (VLF) whistler waves can remediate this threat by deflecting electrons to smaller pitch angles that take them deeper into Earth’s atmosphere. Such VLF transmission was demonstrated with the Demonstration and Science Experiments (DSX) mission. The complex interaction between antenna and local plasma calls for high-fidelity models that allow the computation of the performance of a specific antenna design. To address this gap, SSI proposes to develop a Model for Antennas Immersed in PLasma (MAIPL). MAIPL will consist of a 3D, electromagnetic (EM) particle-in-cell (PIC) solver that calculates antenna surface charging in the presence of a magnetized plasma, the resulting near-field radiation pattern, and the performance of the system in terms of radiated power and efficiency. MAIPL will also characterize the effects of an artificial plasma source on the system. In Phase I, a reduced-dimensionality EM PIC model will be developed and applied to demonstrate propagation of VLF radiation in representative problems. In Phase II, the model will be extended to 3D with multi-scale mesh and parallel computing capabilities that then can be applied to dipole and parametric loop antennas.