Abstract
A macroscopic Coulomb crystal of solid particles in a plasma has been observed. Images of a cloud of "dust" particles, which are charged and levitated in a weakly ionized argon plasma, reveal a hexagonal crystal structure. The crystal is visible to the unaided eye. The particles are cooled by neutral gas to 310 K, and their charge is , corresponding to a Coulomb coupling parameter . For such a large value, strongly coupled plasma theory predicts that the particles should organize in a Coulomb solid, in agreement with our observations.
- Received 25 January 1994
DOI:https://doi.org/10.1103/PhysRevLett.73.652
©1994 American Physical Society