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Title: Observation of Ω mode electron heating in dusty argon radio frequency discharges

The time-resolved emission of argon atoms in a dusty plasma has been measured with phase-resolved optical emission spectroscopy using an intensified charge-coupled device camera. For that purpose, three-dimensional dust clouds have been confined in a capacitively coupled rf argon discharge with the help of thermophoretic levitation. While electrons are exclusively heated by the expanding sheath (α mode) in the dust-free case, electron heating takes place in the entire plasma bulk when the discharge volume is filled with dust particles. Such a behavior is known as Ω mode, first observed in electronegative plasmas. Furthermore, particle-in-cell simulations have been carried out, which reproduce the trends of the experimental findings. These simulations support previous numerical models showing that the enhanced atomic emission in the plasma can be attributed to a bulk electric field, which is mainly caused by the reduced electrical conductivity due to electron depletion.
Authors:
; ; ;  [1] ;  [2]
  1. Institut für Physik, Ernst-Moritz-Arndt-Universität Greifswald, 17489 Greifswald (Germany)
  2. Universitätsrechenzentrum, Ernst-Moritz-Arndt-Universität Greifswald, 17489 Greifswald (Germany)
Publication Date:
OSTI Identifier:
22220699
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Plasmas; Journal Volume: 20; Journal Issue: 8; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; 46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; ARGON; ATOMS; CAMERAS; CHARGE-COUPLED DEVICES; DUSTS; ELECTRIC CONDUCTIVITY; ELECTRIC FIELDS; ELECTRONS; EMISSION SPECTROSCOPY; HEATING; HIGH-FREQUENCY DISCHARGES; IMAGES; NUMERICAL ANALYSIS; PLASMA DIAGNOSTICS; PLASMA SHEATH; PLASMA SIMULATION; RADIOWAVE RADIATION; SENSORS; TIME RESOLUTION