The conditions for effective clustering in a plasma discharge source identified via Monte-Carlo simulations

The assumption that the ionization and coagulation of metal particles in a plasma-generating duster source can be described by the orbital limited mot ion theory, examined by Monte Carlo calculations, was found inadequate. Tha t assumption cannot firstly predict the modes of cluster ionization observe d experimentally Secondly, the effectiveness of coagulation was found to de pend on the initial size of the condensing particles. Specifically, the coa gulation of dust particles proceeds in a satisfactory degree. The coagulati on of single atoms in a cluster source, however, saturates at about 140 ato ms per cluster, in serious underestimation of relevant experimental data. ( C) 1999 Acta Metallurgica Inc.