Dust charge distribution in complex plasma afterglow

¹  School of Physics A28, The University of Sydney - NSW 2006, Australia
²  GREMI (Groupe de Recherches sur l'Énergétique des Milieux Ionisés), CNRS/Université d'Orléans 14 rue d'Issoudun, 45067 Orléans Cedex 2, France, EU

Corresponding authors: lenaic.couedel@univ-orleans.fr lcouedel@physics.usyd.edu.au

Received: 28 July 2008
Accepted: 1 October 2008

Abstract

Dust charge distributions have been measured for the first time in a complex plasma. Experiments were performed late in a discharge afterglow. Residual charges of few hundred particles have been determined. It was found that the mean residual charge is negative but the tail of the distribution extends into the positive-charge region. The experiments were complemented by numerical simulations taking into account discreteness of the charging process and dependence of plasma parameters on the transition from ambipolar to free diffusion. It is shown that the existence of positively charged particles can be explained by the broadening of the dust charge distribution in the late complex plasma afterglow.