Dust-acoustic waves in strongly coupled plasmas with variable dust charge

A generalized theory of dust-acoustic waves in strongly coupled dusty plasm as containing variable-charge dusts or impurities is given. Relaxation proc esses associated with the strong coupling, as well as dust-charge variation , are taken into account. It is shown that the dispersion and damping prope rties of the waves are strongly affected by dust-dust correlation, dust cha rging and viscoelastic relaxations, and dust-neutral collisions. Multiple t ransitions between positive to negative dispersions are also found and disc ussed. (C) 2000 American Institute of Physics. [S1070-664X(00)03308-5].