A nucleation experiment in low gravity conditions: Monitoring and collection of Mg and Zn particles

Abstract

Abstract An experiment on the nucleation and growth of solid particles from the condensation of vapor in low gravity conditions was performed onboard NASA's KC-135 Microgravity Research Aircraft. In addition to the systems to monitor relevant physical parameters, two systems have been developed and used to observe the growth process of the particles and to extract these particles for further microscopic analyses. A dynamic light scattering system is used to measure the in situ mean particle size while a second independent system allows the collection of the nucleated particles directly from the condensation front. These samples have been analyzed in the lab using Scanning Electron Microscopy (SEM). Mean particle sizes are approximately 300 nm and 150 nm for Mg and Zn particles, respectively. Evidence for particle-particle coagulation of Mg into “fractal” like clusters is seen while Zn shows no evidence for any coagulation over the conditions explored.