Electron and ion heating by whistler turbulence: Three‐dimensional particle‐in‐cell simulations

Abstract

AbstractThree‐dimensional particle‐in‐cell simulations of decaying whistler turbulence are carried out on a collisionless, homogeneous, magnetized, electron‐ion plasma model. The simulations use an initial ensemble of relatively long wavelength whistler modes with a broad range of initial propagation directions with an initial electron beta βe = 0.05. The computations follow the temporal evolution of the fluctuations as they cascade into broadband turbulent spectra at shorter wavelengths. Three simulations correspond to successively larger simulation boxes and successively longer wavelengths of the initial fluctuations. The computations confirm previous results showing electron heating is preferentially parallel to the background magnetic field Bo, and ion heating is preferentially perpendicular to Bo. The new results here are that larger simulation boxes and longer initial whistler wavelengths yield weaker overall dissipation, consistent with linear dispersion theory predictions of decreased damping, stronger ion heating, consistent with a stronger ion Landau resonance, and weaker electron heating.