Parametric excitation of surface ion cyclotron extraordinary polarized waves by an external alternating electric field

摘要

An external alternating electric field in the range of ion-cyclotron frequencies is shown to excite extraordinary polarized surface electromagnetic waves at the second harmonic of ion-cyclotron frequencies. The kinetic model of a uniform semi-bounded plasma is applied. Plasma electrodynamical properties are described by using the Vlasov-Boltzmann kinetic equation in the approach of weak spatial plasma dispersion. Two components of these modes' wave vector, which are oriented across an external steady magnetic field, are taken into account. Fields of these ion-cyclotron modes are described by Maxwell equations. Their phase velocity is assumed to be much lower than light velocity. The external alternating electric field is assumed to be uniform and monochromatic. The nonlinear boundary condition is formulated for the tangential magnetic field of the studied surface waves (SW). An infinite set of equations is derived for the values of tangential electric field harmonics on the plasma interface. This set is solved using the approach to the wave packet consisting of the main harmonic and two nearest satellite harmonics. Simple analytical expressions for the growth rates of parametric instability of these SW are derived. The influence of plasma parameters on their parametric excitation is numerically analyzed.