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Title: Neutral particle dynamics in a high-power RF source

Previous studies on the spatial discharge structure in the SPIDER source of negative hydrogen/deuterium ions carried out at low applied power are extended towards description of the discharge maintenance under the conditions of the actual rf power deposition of 100 kW planned for a single driver of the source. In addition to the expected higher electron density, the results show strong increase of the electron temperature and of the temperatures of the neutral species (hydrogen atoms and molecules). In the discussions, not only the spatial distribution of the plasma parameters but also that of the fluxes in the discharge (particle and energy fluxes) is involved. The obtained results come in confirmation of basic concepts for low-pressure discharge maintenance: (i) mutually related electron density and temperature as a display of the generalized Schottky condition, (ii) discharge behavior governed by the fluxes, i.e. strong nonlocality in the discharge, and (iii) a non-ambipolarity in the discharge regime, which originates from shifted maxima of the electron density and temperature and shows evidence in a vortex electron flux and in a dc current in a rf discharge, the latter resulting from a shift in the positions of the maxima of the electron density and plasmamore » potential.« less
Authors:
; ;  [1] ;  [2]
  1. Faculty of Physics, Sofia University, 5, J. Bourchier Blvd., Sofia BG-1164 (Bulgaria)
  2. Department of Applied Physics, Technical University-Sofia, 8, Kl.Ohridski Blvd., Sofia BG-1000 (Bulgaria)
Publication Date:
OSTI Identifier:
22391444
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 1655; Journal Issue: 1; Conference: NIBS 2014: 4. International Symposium on Negative Ions, Beams and Sources, Garching (Germany), 6-10 Oct 2014; Other Information: (c) 2015 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; 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; ATOMS; DEUTERIUM IONS; ELECTRIC CURRENTS; ELECTRIC DISCHARGES; ELECTRON DENSITY; ELECTRON TEMPERATURE; ELECTRONS; HYDROGEN; ION SOURCES; MAINTENANCE; MOLECULES; NEUTRAL PARTICLES; PLASMA; PLASMA POTENTIAL; RF SYSTEMS; SPATIAL DISTRIBUTION; VORTICES