Convective excitation of quasistatic waves in an inhomogeneous anisotropic plasma

Local as well as surface waves excited in a streamingless plasma are investigated. In addition to the gradient instabilities of an isothermal plasma now branches of a convective type are found in plasmas with a hot electron componentZ T_e T_i. Both their frequencies and growth rates may exceed the ion cyclotron frequency, >_Bi even if the effect of the finite ion Larmor radius is negligible. Then the surface waves may become of enhanced importance. We compare, therefore, the conditions for excitation and the growth rates of the surface waves with those of the short wavelength (local) perturbations. Upper estimates of the saturated wave amplitudes are also given. For a special profile of the plasma density the problem is solved analytically also in the plasma boundary layer.On leave of absence from the Physical and Technical Institute, Kharkov, U.S.S.R.