Kinetic dynamics of an initial perturbation in a plasma with negative ions

Relaxation of initial perturbation in a plasma with negative ions, the cause whereof may consist in a laser photo-break-off, is considered on the basis of kinetic approach. Expressions for describing the plasma density relaxation with negative ions in a laser channel are obtained. The hydrodynamic approximation by cold positive ions (T+ << Te) is adequate. The hydrodynamic approach by higher temperatures of positive ions (T+ ≤ Te) proves to be incorrect, while the Landau attenuation effect begins to show its essential influence