Low-frequency electromagnetic fluctuations in a plasma with strong external magnetic field

A general approach to the description of the fluctuations of the electric a nd magnetic fields in a plasma placed in a strong external magnetic field i s developed. The wave dispersion is considered and the dependences of the d amping rates of the Alfven and magnetosonic waves on the propagation angle and parameters of the plasma are analysed. The spectral distributions of th e fluctuations of the electric and magnetic fields in the frequency ranges omega much less than omega(Bi) and omega less than or similar to omega(Bi) of the spectrum for the plasma with strong external magnetic field are stud ied in detail. The spectral distributions of the fluctuations of the electr ic and magnetic fields in non-equilibrium plasmas are treated. Effective te mperatures have been introduced both for the collective Alfven and magnetos onic fluctuations and for the incoherent fluctuations in low-frequency rang e; they can be used as convenient parameters for the description of the non -equilibrium state of plasmas in diagnostics in facilities devised for real ization of the controlled thermonuclear fusion.