SELF-CONSISTENT CHARGED-PARTICLE MOTION IN NEGATIVE-ION PLASMAS

The self-consistent one-dimensional kinetic theory of relaxation of a low pressure quasineutral negative-ion plasma destroyed in a limited region by a powerful laser light pulse is developed. Using the self-similar method, well known in hydrodynamics, we examine the counterflow of the negative plasma species and show the important role of the self-consistent electric field. The negative-ion temperature determined from the ballistic model is valid when the ratio of negative-ion to positive-ion densities is lower than 0.1. The overshoot of electron density that was observed experimentally is described by this method. We show that the overshoot can disappear when the positive-ion mass or temperature goes up. The self-similar solutions are also supported by numerous experimental results.