One-dimensional modulational instability models of intense Langmuir plasma oscillations using the Silin-Zakharov equations

The modulational instability mechanisms of intense Langmuir oscillations in a plasma are reviewed both for field energy densities below (Zakharov's model) and above (Silin's model) the plasma's thermal energy density. It is shown by a one-dimensional example that V E Zakharov's mechanism involving nonlinear absorption of Langmuir oscillations in plasma also holds for intense cold plasma fields described by V P Silin's model. It is also shown that the development mechanisms of the modulational instability of Langmuir oscillations are similar for nonisothermal and cold plasmas. Hybrid models treating electrons quasihydrodynamically and ions as particles are analyzed in detail, which allows the study of the direct mechanism by which energy is transferred to ions in the instability development process.