Interaction potentials in a plasma with streaming ions and non-spherical dust rods

Interaction potentials in a plasma are calculated in the presence of a diel ectric response function that accounts for ion streaming and dipole moments of non-spherical charged dust rods. It is found that, besides the Debye-Hu ckel potential, there appears an oscillatory wake potential due to the comb ined effects of dust ion-acoustic (DIA) waves and dipole oscillons that res onate with a test charge. In the negative part of the wake potential, the i ons can be focused and negatively charged dust rods may attract each other, forming organized structures. Thus, our investigation offers a clue for th e dust rod alignment, which has been observed in some laboratory experiment s. (C) 2001 Elsevier Science B.V. All rights reserved.