Asymptotic Representations of the Solution of the Problem on the Wave Field Structure Formed by the Plane Wave Incidence on a Semitransparent Ingomogeneous Plasma Layer (a Model Problem)

Different asymptotic representations of the exact solution of the problem about the oblique incidence of a plane wave on a plasma layer are considered. The plasma layer has a finite thickness and a parabolic profile of the electron density. The large parameter of the asymptotic forms is the ratio of the layer thickness to the wavelength. The following three cases are analyzed: the layer reflecting in the geometrical optics (GO) approximation, the layer being transparent in the GO approximation, and the critical layer. It is shown that the semitransparency effect is significant in the considerable neighborhood of the critical value of the layer parameters for given characteristics of the incident wave. The correct asymptotic forms are suggested for the adequate calculation of this effect. The results of the numerical modeling of the wave field structure are represented in the conditions of the considerable semitransparency effect. These results are compared with the GO solution.