Kinetic theory of plasma and gas. Interaction of high-intensity laser pulses with plasmas

A kinetic theory of tenuous plasmas and gases is elaborated, which is physically equivalent to the conventional theory and is based on the construction of distribution function propagators that depend on these distribution functions. A theory of short high-intensity laser pulse–plasma interaction is constructed on the basis of this kinetic theory. A general characteristic is provided for the absorption of high-intensity laser radiation by a plasma and its associated parametric instabilities. Considered next are diverse regimes of subpicosecond relativistic laser pulse–plasma interaction. In the framework of the theory elaborated here, an investigation was made of hot-electron production in the interaction of relativistic femtosecond laser pulses with a weakly nonuniform plasma at densities of the order of and above the critical density, as well as of fast-proton production in the irradiation of a thin foil with an admixture of hydrogen. Calculations were carried out with real ion charges and at realistic ion charges and realistic plasma densities. The results are consistent both with calculations by the generally accepted particle-in-cell technique and with experimental data.