Reflection of ion acoustic waves from a dusty plasma with a dust size distribution

A general dispersion relation for ion acoustic waves in a plasma containing charged dust grains is obtained taking an account of dust size distributio n. The dust size is given by a power law distribution. Assuming that the du ty plasma is well separated from the dust free plasma, the influence of thi s distribution is studied on the calculated reflection coefficient. On the basis of this reflection coefficient we have tried to interpret the mainten ance of large scale dust structures in the plasma environment.