Identify the species driving fast magnetosonic/whistler waves

Determine which plasma population—the proton core, proton beam, or electrons—drives the growth or damping of fast magnetosonic/whistler waves in the hybrid simulation, using an analysis beyond the linear PLUME description.

Background

The study finds that fast magnetosonic/whistler waves are clearly present in the wavelet helicity spectrogram but have weak or near-zero linear growth rates in the PLUME analysis. Moreover, the species-resolved growth-rate decomposition breaks down when the normalized damping or growth rate is sufficiently large, so the contributions of the core, beam, and electrons cannot be interpreted reliably within the applicable linear approximation.

Because the observed fast magnetosonic/whistler waves may be nonlinearly generated and strongly damped, identifying which plasma population is responsible for their growth or damping remains unresolved by the methods used in the study.