Radiation of sound from a charged dust particle moving at high velocity

Radiation of sound waves from a rapidly moving charged dust particle in dusty plasmas is considered. For the limiting case, where the dusty plasma can be described by a Vlasov-type equation, analytical expressions are derived for the fully three-dimensional radiation pattern, including the effects of the Landau damping of sound waves. The results are illustrated by simple cases, which can be expressed by known functions. The radiation pattern obtained can be used to determine the sound speed, but also the temperature ratio of dust and singly charged particles, electrons, and ions. The analysis applies equally well for a fast charged dust particle propagating through a thermal plasma. The analytical results are supported by numerical simulations, including also a study of magnetized plasmas which are not as easily tractable for analytical investigations. (C) 2003 American Institute of Physics.