The role of electron density in magnetic turbulence

Inertial range energy transfer, decorrelation, and energy spectra are studi ed analytically and numerically for strongly anisotropic magnetohydrodynami c (MHD) turbulence augmented by electron density evolution. The model is re levant to interstellar turbulence and magnetic turbulence in fusion devices . For long wavelengths (compared to the ion gyroradius), magnetic and kinet ic energies are equipartitioned through interactions that decorrelate on th e Alfvenic time scale. Internal energy transfer is governed by advection an d decorrelates on the eddy turnover time scale. For short wavelengths, the roles of internal and kinetic energy reverse. Magnetic and internal energie s are equipartitioned by the kinetic Alfven interaction, while kinetic ener gy evolves under a decoupled fluid straining interaction. The spectral indi ces for magnetic, kinetic, and internal energies are -3/2, -3/2, and -7/4 f or long wavelengths, and -2, -5/3, and -2 for short wavelengths. (C) 2001 A merican Institute of Physics.