Discrete charging model and parametric excitation of the so-called acoustic mode in dusty plasmas

A simple harmonic oscillator model has been considered for the statistical charging process of the dust grainlike impurity ions. Treating it as a driv er eigenmode and the plasma eigenmodes under consideration (the acoustic mo des and plasma oscillations! as the idler modes, a simple process of parame tric excitation of the idler modes has been discussed. It is suggested that the proposed model could provide a seeding mechanism for resonant excitati on of the electrostatic plasma modes. (C) 1999 American Institute of Physic s. [S1070-664X(98)02109-0].