Propagation and application of VLF waves generated by HF heating of ionosphere in the magnetosphere

It has been proposed that VLF radiations, resulting from high-frequency (HF) transmitter heating of the ionosphere, can be potentially used for artificial radiation belt remediation. In the present study we first perform a parametric study of these VLF wave propagation paths and characteristics in the near-Earth magnetosphere, using our own developed ray tracing code. Then, based on the resonance condition and dispersion equation, we make an analysis about the energy of electrons resonating with these artificial VLF waves. The results indicate that VLF waves can propagate outward by magnetospheric reflection and finally settle down at certain higher L-shells in the inner magnetosphere. The waves can propagate further when the frequency is lower or the initial latitude is higher. But, it is also possible that VLF waves touch the ionosphere and get absorbed there without any magnetospheric reflection, if the waves are launched at very high latitudes. In the magnetosphere, VLF waves at higher latitude or lower L-shell can resonate with higher energy electrons and at lower latitude and higher L-shell can resonate with lower energy electrons. For higher harmonic, resonance interaction needs higher energy electrons.