Synthesis of water ice particles in a plasma chamber

Abstract

[1] We describe a new type of experiment where micrometer-size water ice particles are created from D 2 and O 2 in the plasma chamber, with the electrodes cooled by liquid nitrogen. In the reactor, D 2 and O 2 are decomposed by electron impacts and form precursors for chemical reactions. Water ice particles are produced within a second after plasma ignition. We propose a simple growth/sedimentation model, which reproduces the experimental data.

Study on morphology and growth of water–ice grains spontaneously generated in a laboratory plasma

“…1 shows a photo of the water-ice dusty plasma; a detailed description is given elsewhere (Chai and Bellan, 2013). The apparatus incorporates design features of a previously existing experiment at the Max-Planck-Institute for Extraterrestrial Physics (Shimizu et al, 2010) but differs in two important aspects: the inter-electrode separation is adjustable and water vapor is directly injected into an argon plasma instead of forming water molecules in a plasma created from a fill of D 2 and O 2 . Adjustable electrodes provide a wider range of pressures for plasma breakdown and direct injection of water vapor into a pre-existing argon plasma provides independent means for controlling and measuring the water vapor pressure.…”

Measurement of net electric charge and dipole moment of dust aggregates in a complex plasma

“…The formation of ice particles on dust grains in Earth's upper atmosphere gives rise to unusual phenomena such as noctilucent clouds and localized electron depletions ("biteouts") associated with these clouds [3]. These ice particles also reflect and absorb energy, influencing atmospheric dynamics [4]. Dust is also readily found in magnetic confinement fusion devices, which has consequences for the safety of fusion reactors as well as their operation and performance [5].…”

Vortex motion of dust particles due to non-conservative ion drag force in a plasma

“…4 Dust particle vortex flow has attracted much recent attention because of relevance to waves, instabilities, and turbulent transport. 5,6 Dust particle vortex flow has been observed in microgravity experiments, 7,8 in experiments where the gravitational force is compensated by the thermophoretic force, 9,10 and in experiments where the vortex flow is externally induced by a probe or by a laser. 11,12 However, the cause of vortex flows remains controversial.…”

“…11,12 However, the cause of vortex flows remains controversial. Akdim and Goedheer 13 and Schwabe and Graves 14 postulated that a non-zero curl of the total force exerted on dust particles causes vortex flow; Shimizu et al 10 argued that dust particle vortex flow is induced by vortex neutral gas flow caused by the temperature gradient between two electrodes; and Fortov et al 15 claimed that dust particle vortex flow results when the gradient of dust charge is not parallel to non-electrostatic forces such as the ion drag force and gravitational force.…”