Dust particulate-phonon interaction and the resulting instability

Summary form only given. A highly charged test dust-particulate placed in the sheath region of a low-temperature discharge plasma is known to form an oscillatory wake potential. the attractive interaction produced by such an oscillatory potential is considered to be responsible for the formation of plasma crystals. The dust particulate-phonon interaction Hamiltonian was derived and the resulting effective potential was found to agree with the wake potential derived by the test particulate method. The Hamiltonian formulation revealed that the wake potential is the result of interaction between a pair of dust particulates by exchanging phonons. We study the instability associated with the system in which a collection of dust particulates interact among themselves by phonon exchange. It is found that the system becomes hydrodynamically unstable. Such an instability may be relevant to the phase transition of a coulomb crystal observed experimentally in a radio frequency discharge chamber.