Theory of ion-acoustic turbulence in plasma with anisotropically heated ions

A simple approximation extending the theory of ion-acoustic turbulence (IAT) is proposed. The approximation is based on the idea of efficient anisotropic ion heating in the Coulomb plasma model. The model makes it possible not only to employ the main results of the existing IAT theory without an assumption of strong ion collisions, but also to substantially extend them. The role of Cherenkov absorption of ion-acoustic waves is revealed. This absorption is caused by an anisotropic ion distribution in the new regimes of IAT that are related to its angular distribution and manifest themselves in electron and ion heating. A specific feature of the model is the finite time of existence of one of the IAT regimes under study.