Astrophysical Gyrokinetics: Basic Equations and Linear Theory

摘要: Magnetohydrodynamic (MHD) turbulence is encountered in a wide variety of astrophysical plasmas, including accretion disks, the solar wind, and interstellar intracluster medium. On small scales, this often expected to consist highly anisotropic fluctuations with frequencies compared ion cyclotron frequency. For number applications, scales are also collisionless, so kinetic treatment necessary. We show that well described by low-frequency expansion theory called gyrokinetics. This paper first series examine turbulent plasmas gyrokinetic limit. derive explain nonlinear equations explore linear properties gyrokinetics as prelude simulations. The dispersion relation for obtained, its solutions those hot-plasma theory. These results used validate performance simulation code GS2 parameter regimes relevant plasmas. New on global energy conservation derived. briefly outline several problems be addressed future simulations, particle heating hot flows magnetic electric field power spectra origin small-scale density