FORMATION OF SILVER CLUSTERS IN NOZZLE EXPANSIONS

The first successful experiments to generate continuum silver cluster beams from nozzle expansions are described. A mixture Ar/Ag expands out of a conical nozzle (0.35 mm dia., 10-degrees cone angle, length 17 mm). At 2150 K, total pressure 300 kPa, silver partial pressure 8 kPa the silver intensity measured with a rate meter 479 mm away from the source is 1.8 nm/s, or 0.02 gm-2 s-1. The data for the onset of clustering confirm the predictions of the scaling laws developed to compared condensation in nozzle expansions of metal vapors with that of rare gases.