On the disturbance caused by a stationary dust grain in a flowing plasma

A study has been made of the distributions of electric and velocity potentials around a dust particle immersed in a flowing, collisionless plasma. The dust particle acts as a sink for both ions and electrons, since it can draw no net current in the steady state. The dust particle is also assumed to be small compared with the Debye distance. An earlier paper considered the flow around an object much larger than the Debye distance [1]. In the present case an analytical solution has been found for both the electric potential and the velocity potential in cases where the ion streaming is slow. The electric potential contains a strong dipole component and a lesser contribution due to the small space charge associated with a quasi-neutral region. Further modelling and numerical work is required to obtain the solution to the problem for high ion streaming velocities.