Transformations of dust structures in glow DC discharge in neon: effect of gas temperature and discharge current

Abstract

The dependence of the shape of the dust structures on discharge current and pressure in neon glow DC discharge at temperatures 77 K and 295 К has been studied experimentally. It was found that when the discharge current was increased, the radial size of the dust cloud increased, and the axial size decreased. It was found that at 295 К the dust clouds were formed by individual dust particles, while at 77 K they consisted of a mixture of dust particles and simplest threadlike clusters formed from dust particles. The decrease of gas pressure led to increase in distances between the dust particles and clusters, and reduced the dynamic stability of the dust particles and clusters. At 295 К an increase of the discharge current resulted in the formation of voids in dust structures, while at 77 K the formation of the dust structures with voids was not observed even at maximum discharge currents. The formation of clusters at cryogenic cooling can be interpreted as ‘condensation’ and ‘deposition’ of dust particles.