Mathematical simulation of the weak Langmuir turbulence dynamics

The time evolution of various anisotropic packets of Langmuir waves owing to their induced scattering at plasma ions is considered. The problem of isotropization of a weak Langmuir turbulence in dependence of initial data is studied. As has been found, the process of isotropization may be substantially longer than the process of the energy pumping-over over the spectrum. Three characteristic types of anisotropic spectra of Langmuir waves are examined. The evolutions of these three types of spectra are different. Curves of spatial distribution of the spectrum are given. In addition to the angle transformation of the spectrum, narrowing of the spectrum in the wave number space occurs. Results of numerical studies of the spectrum anisotropy as a time function are also given