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Title: The effect of a direct current field on the microparticle charge in the plasma afterglow

Residual charges of individual microparticles forming dense clouds were measured in a RF discharge afterglow. Experiments were performed under microgravity conditions on board the International Space Station, which ensured particle levitation inside the gas volume after the plasma switch-off. The distribution of residual charges as well as the spatial distribution of charged particles across the cloud were analyzed by applying a low-frequency voltage to the electrodes and measuring amplitudes of the resulting particle oscillations. Upon “free decharging” conditions, the charge distribution had a sharp peak at zero and was rather symmetric (with charges concentrated between −10e and +10e), yet positively and negatively charged particles were homogeneously distributed over the cloud. However, when decharging evolved in the presence of an external DC field (applied shortly before the plasma switch-off) practically all residual charges were positive. In this case, the overall charge distribution had a sharp peak at about +15e and was highly asymmetric, while the spatial distribution exhibited a significant charge gradient along the direction of the applied DC field.
Authors:
 [1] ;  [2] ; ; ; ; ;  [1] ;  [3] ;  [1] ;  [4] ; ;  [5] ;  [6] ; ; ; ;  [7]
  1. Max Planck Institute for extraterrestrial Physics, P.O. Box 1312, Giessenbachstr., 85741 Garching (Germany)
  2. (France)
  3. Centre National de la Recherche Scientifique, Aix-Marseille-Université, Laboiratoire de Physique des Intéractions Ioniques et Moléculaires, UMR 7345, 13397 Marseille cedex 20 (France)
  4. (United States)
  5. Groupe de Recherches sur l'Energétique des Milieux Ionisés, UMR7344, CNRS, Univ. Orléans, F-45067 Orléans (France)
  6. Yuri Gagarin Cosmonauts Training Center, RU-141160 Star City (Russian Federation)
  7. Joint Institute for High Temperatures, RU-125412 Moscow (Russian Federation)
Publication Date:
OSTI Identifier:
22218392
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Plasmas; Journal Volume: 20; Journal Issue: 12; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; AFTERGLOW; CHARGE DISTRIBUTION; CHARGED PARTICLES; DIRECT CURRENT; ELECTRIC POTENTIAL; HIGH-FREQUENCY DISCHARGES; INTERNATIONAL SPACE STATION; PLASMA DENSITY; PLASMA DIAGNOSTICS; PLASMA SWITCHES; PLASMA WAVES; SPATIAL DISTRIBUTION; WEIGHTLESSNESS