Simulation of nonlinear wave particle interactions in space plasmas using the VHS technique

This paper is concerned with a new technique for the numerical simulation of nonlinear wave particle interactions in collision free space plasmas. The problem looked at is the interaction between a continuous distribution of hot electrons (--KeV) and a narrow band of quasi narrow band EM wave field in the VLF band (4kHz). The whistler wave field is assumed to be ducted in that the local Κ vector is aligned parallel to the local magnetic field. The important interaction is a nonlinear cyclotron resonance between electrons with the resonance velocity and the wave field. The parabolic variation of ambient magnetic field with distance confines the interaction region to with a few thousand kms of the magnetospheric equator of L=4. Such nonlinear wave particle interactions cause a wide variety of phenomena in the VLF band, most notably triggered VLF emissions. The author numerically simulates a rising frequency emission