Self-action and absorption of the electromagnetic wave beam energy at relativistic nonlinearity in a inhomogeneous plasma

The plasma heating by intensive laser radiation is studied in the relativistic range, when the interaction of the powerful laser electromagnetic field and the plasma is governed by the relativistic nonlinearity. The main processes of this range are the relativistic instability and self-focusing which are expected to enhance considerably the efficiency of the beam energy transformation into plasma. The nonlinear parabolic differential equation describing the behaviour of the beam field amplitude was solved numerically. The qualititative characteristics of the solutions are discussed in detail and are interpreted by physical terms. (D.Gy.)