Observation of submicron dust particles trapped in a diffused region of a low pressure radio frequency plasma

Abstract

Submicron dust particles (Cu, φ 50 nm) were observed to be trapped in an rf plasma at relatively low pressure. The laser light scattering by particles shows the time evolution of the dust particles for several hours after pulsed injection of the particles. The dust particles were localized in the diffused region as a large volume cloud. The suspension mechanism of the dust particles in the diffused plasma was explained by an electrostatic force due to the potential structure. The spatial distribution of the charge of the dust particles was determined by this potential structure. The dispersion relations of the self-excited dust acoustic waves were adopted to confirm the spatial distribution and the time evolution of the charge of the dust particles. © 2001 American Institute of Physics.