THE FLOW DIFFUSION NUCLEATION CHAMBER - A QUANTITATIVE TOOL FOR NUCLEATION RESEARCH

We have developed a flow diffusion nucleation chamber designed to quan titatively investigate the nucleation of vapors. The design and operat ional characteristics of the nucleation chamber are presented and disc ussed. Critical supersaturation data obtained with this nucleation cha mber are compared to literature data obtained using a thermal diffusio n cloud chamber. The flow nucleation chamber results accurately reprod uce the diffusion cloud chamber data. Results of preliminary measureme nts of nucleation at ambient pressure in the presence of different bac kground gases are presented. These data suggest that the nature of the background gas may influence nucleation at ambient pressure. These da ta, while still of a preliminary nature, are consistent with data alre ady published obtained at elevated pressures using a specially designe d high pressure cloud chamber also in our laboratory. (C) 1996 America n Institute of Physics.