Convective excitation of quasistatic waves in an inhomogeneous anisotropic plasma. I

The local as well as the surface waves excited in a streamingless plasma are investigated. In addition to the gradient instabilities of an isothermal plasma, branches of a convective type are found in the plasma with a hot electron component, ZTsub(e parallel)>>Tsub(i perpend.). Both their frequencies and growth rates may exceed the ion cyclotron frequency even if the effect of the finite ion Larmor radius is negligible. The surface waves may be of considerable importance. Therefore, the conditions are compared of the 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 particular profile of the plasma density the problem is solved analytically also in the plasma boundary layer. (author)