Role of neutral-particle bombardment in dust-dust interactions in plasmas

It is shown that the interaction of dust with neutral plasma particles can lead to attractive forces between dust particles, both in the case where th e distance between dust particles is less than the mean free path of neutra l particles and in the case where it is greater. The expressions for attrac tive forces differs in the two limits only by a numerical coefficient. The additional force of dust interaction is found to be due to the neutrals cre ated by recombination of charged plasma particles on the surface of dust pa rticles. The influence of radiative dust cooling on dust-dust interaction i s considered.