Three-Dimensional Hybrid Kinetic Simulations of Solar Wind Turbulence

The interplanetary medium hosts a solar wind, which contains a broadband turbulent spectrum of large-amplitude Alfven waves. We present results from hybrid-kinetic simulations of this turbulent and essentially collisionless system. We confirm power-law indices obtained in previous analytical and numerical (e.g., gyrokinetic) studies, and carefully explore the location of the spectral break and physics occurring at the ion-Larmor scale. In the low-beta regime, we find evidence of perpendicular ion heating, which we interpret as stochastic heating arising from interactions between ions and strong fluctuations at wavelengths comparable to the ion-Larmor scale. We explore the dependence of ion heating on plasma beta. Finally, we discuss kinetic features in the ion distribution function and present field-particle correlations.