Recent advances in the theory of nonlinear surface waves

Transition radiation is a process of a rather general character. It occurs when some source, which does not have a proper frequency (for example, a charge) moves at a constant velocity in an inhomogeneous and (or) nonstationary medium or near such a medium. The simplest type of transition radiation takes place when a charge crosses a boundary between two media (the role of one of the media may be played by vacuum). In the case of periodic variation of the medium, transition radiation possesses some specific features (resonance transition radiation or transition scattering). Transition scattering occurs, in particular, when a permittivity wave falls onto an nonmoving (fixed) charge. Transition scattering is closely connected with transition bremsstrahlung radiation. All these transition processes are essential for plasma physics. Transition radiation and transition scattering have analogues outside the framework of electrodynamics (like in the case of Vavilov?Cherenkov radiation). In the present report the corresponding range of phenomena is elucidated, as far as possible, in a generally physical aspect.

Transition Radiation and Transition Scattering

A traditional cold‐plasma boundary model is revised to allow for proper description of nonlinear effects in surface wave propagation. It is shown that induced nonlinear surface currents can exist at the boundary. As an example, the third‐order ponderomotive phenomena are considered, and the effect of the boundary condition on these nonlinear interactions is examined.

Boundary effects on the nonlinear interactions of surface waves

Ion-acoustic surface waves in a highly collisional plasma are considered. It is shown that the dispersion and damping of these waves differ considerably from those for a weakly collisional plasma.

Low-frequency surface acoustic waves in a collisional plasma

This paper derives a nonlinear equation containing up to third-order terms in the field on the basis of the kinetic theory, which describes the interaction of high-frequency surface potential waves in a semiinfinite collisionless plasma. The modulation instability of the regular pump field of the surface waves is investigated. The characteristics of nonlinear interaction related to the specifics of the surface waves are analyzed.

A. N. Stepanovich

Papers

Nonlinear interaction of surface potential waves in a semiinfinite plasma