Modelling of dust grain formation in a low-temperature plasma reactor used for simulating parasitic discharges expected under tokamak divertor domes

• Published in: Plasma sources science & technology Vol. 19; no. 3; p. 034023
• Main Authors: Michau, A, Lombardi, G, Arnas, C, Delacqua, L Colina, Redolfi, M, Bonnin, X, Hassouni, K
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Bristol IOP Publishing 01.06.2010; Institute of Physics
• Subjects: Applied sciences; Basic studies of specific kinds of plasmas; Carbon; Cathode sputtering; Clusters; Controled nuclear fusion plants; Direct current; Dust; Dusty or complex plasmas ; plasma crystals; Energy; Energy. Thermal use of fuels; Exact sciences and technology; Installations for energy generation and conversion: thermal and electrical energy; Magnetic confinement and equilibrium; Mathematical models; Nanostructure; Physics; Physics of gases, plasmas and electric discharges; Physics of plasmas and electric discharges; Power exhaust; divertors; Reactors; Tokamaks; Trapping; Thermonuclear reactors; Tokamak; Nucleation; Electric discharges; Theoretical study; Tritium; Dusty plasmas; Thermonuclear fusion; Carbon; Plasma facing component; Sputtering; Cold plasma; Fusion reactor divertors; Graphite; Confined plasma; Argon; Edge plasma
• ISSN: 0963-0252; 1361-6595
• DOI: 10.1088/0963-0252/19/3/034023

The presence of nanostructured dust particles has been reported in thermonuclear fusion reactors with carbon plasma-facing components. These particles contribute to tritium retention and pollution of the edge plasma. Understanding the way these particles can grow in the plasma phase is necessary for designing engineering solutions that avoid or at least limit their formation. As a first step towards this goal, this paper presents a numerical study of the formation of dust in a simple model laboratory electrical discharge: a dc discharge generated in argon with a graphite electrode. The aim here is to investigate whether carbon sputtering through ion and fast neutral bombardment of the cathode and subsequent molecular growth of carbon clusters and particle nucleation and development can explain dust formation in this model discharge. Results show that field reversal effects and negative cluster formation and trapping can fully explain dust formation in such a dc discharge.