Glow and dust in plasma boundaries

TL;DR

This paper investigates plasma sheath boundaries using dust particles and optical emission measurements, revealing how local maxima in emission relate to quasi-neutrality breaking and dust wave onset.

Contribution

It introduces a combined diagnostic approach using dust particles and optical emission to analyze sheath boundary phenomena in complex plasmas.

Findings

Optical emission maxima coincide with sheath boundary quasi-neutrality breaking.

Dust density waves are observed at the sheath boundary in high-density dust clouds.

Vertical force profiles from dust trajectories confirm sheath boundary locations.

Abstract

The sheath region is probed in different complex plasma experiments using dust particles in addition to measurement of the optical emission originating from the plasma. The local maximum in optical emission coincides with the breaking of quasi-neutrality at the sheath boundary as indicated by the vertical force profile reconstructed from dust particle trajectories, as well as by the local onset of dust density waves in high density dust clouds suspended in a dielectric box.