Instabilities of dust acoustic waves in a plasma with a significant background pressure of neutrals have been investigated. A long wavelength mode is found to be unstable due to recombination of electrons and ions on the surface of dust particles. At short wavelengths, a dissipative instability driven by relative drift between ions and the dust particles is found to be important. Nonlinearly, the short wavelength modes lead to the formation of $K-dV$ solitons whereas the long wavelength end is dominated by modulational instabilities.

• Received 18 March 1997

DOI:https://doi.org/10.1103/PhysRevLett.79.423