Formation of droplets in weightless complex plasmas

Microparticles immersed in a low-temperature plasma acquire strong negative charges and thus repel each other. Nevertheless, effective attraction between the microparticles in such a complex plasma can occur due to the interplay between the fluxes of plasma ions and the microparticles. Here, we report the observation of droplets formed in a complex plasma during a parabolic flight, and explain their formation in terms of the ion drag force that sustains the droplet. We have found a good agreement between the experimentally determined droplet size and its theoretical estimate using the ion drag force mechanism. Lower values of the electron temperature result in better agreement, as is consistent with the pulsed mechanism of discharge used experimentally.

Automated summary

In a complex plasma, microparticles repel each other due to strong negative charges acquired in a low-temperature plasma, but effective attraction can occur through the interplay between plasma ion fluxes and microparticles. Observations of droplets formed in a complex plasma during a parabolic flight were explained by the sustained ion drag force. The experimentally determined droplet size matched well with the theoretical estimate using the ion drag force mechanism, particularly with lower electron temperature values.