New paradigm for the self-consistent modeling of wave-particle and wave-wave interactions in the saturation of electromagnetically driven parametric instabilities

We introduce two new and complementary simulation models, which have domain s of quantitative agreement, for the self-consistent evolution of the elect ron distribution, Langmuir decay cascades, and Langmuir collapse. In our re duced-description particle-in-cell (RPIC) simulations, Langmuir decay casca des and cycles of collapse are seen for the first time in particle simulati on. The velocity distribution in our Zakharov model is evolved using quasil inear diffusion plus Cerenkov emission loss and agrees in expected domains with the RPIC results. These techniques promise to solve long known problem s in the standard simulations of laser-plasma instabilities.