Spectrum and impedance properties of a plasma in a helical magnetic field

Theoretical and numerical analyses of interaction between Alfven frequency range fields and a nonhomogeneous cylindrical plasma in a helical magnetic field have been carried out (for some time), this plasma being used to simulate a tokamak plasma. By this a MHD plasma model, considering gyrotropy as well as a kinetic model, considering finite ion Larmor radius effect and the thermal motion of electrons during RF field generation, have been used. With the help of MHD and kinetic numerical codes the spectra of global and slow (kinetic) Alfven waves, fast magneto-sonic and surface waves have been well studied for small-size tokamak with the gyrotropy parameter large enough: ω/ωci∼=0,3-0,5. In the present paper we investigate the spectra (dependence of eigenfrequencies on kza=na/R) of a global kinetic Alfven, fast magneto-sonic and surface waves, and active and reactive impedance of helical antennas for INTOR-type tokamak plasma parameters. (author) 4 refs., 5 figs