Waves in two component electron-dust plasma

A self-consistent model of linear waves propagating in a two component dust y plasma whose constituents are positively charged dust grains and electron s is presented. Ionization and recombination processes on the dust particle surface, elastic Coulomb collisions of electrons with dust, electron-neutr al collisions, dust-electron and dust-neutral collisions, as well as dust c harge variations are taken into account. The relationships between the char acteristic frequencies of these processes are studied. A linear dispersion relation is obtained and some limiting cases are analyzed. It is shown that Langmuir waves are damped due to electron collisions. It is also found tha t low frequency waves are always stable in such a system, and there exist t wo dust-acoustic modes: (1) the usual dust acoustic mode, similar to the io n acoustic wave in electron-ion plasmas; and (2) an acoustic mode with redu ced phase velocity, associated with dust particle charge variations. The st atic response of electron-dust plasmas is examined and the screening length of the system is determined. (C) 2001 American Institute of Physics.