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Transition from moving to stationary double layers in a single-ended Q machineLarge-amplitude (less than about 100 percent) relaxation oscillations in the plasma potential are known to be generated when the cold endplate of a single-ended Q machine is biased positively. These oscillations are associated with double layers that form near the hot plate (plasma source) and travel toward the endplate at about the ion-acoustic velocity. At the endplate they dissolve and then form again near the hot plate, the entire process repeating itself in a regular manner. By admitting a sufficient amount of neutral gas into the system, the moving double layers were slowed down and eventually stopped. The production of stationary double layers requires an ion source on the high-potential side of the double layers. These ions are provided by ionization of the neutral gas by electrons that are accelerated through the double layer. The dependence of the critical neutral gas pressure required for stationary double-layer formation on endplate voltage, magnetic field strength, and neutral atom mass has been examined. These results are discussed in terms of a simple model of ion production and loss, including ion losses across the magnetic field.
Document ID
19900056506
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Song, Bin
(Iowa Univ. Iowa City, IA, United States)
Merlino, R. L.
(Iowa Univ. Iowa City, IA, United States)
D'Angelo, N.
(Iowa, University Iowa City, United States)
Date Acquired
August 14, 2013
Publication Date
August 1, 1990
Publication Information
Publication: Physics of Fluids B
Volume: 2
ISSN: 0899-8221
Subject Category
Plasma Physics
Accession Number
90A43561
Distribution Limits
Public
Copyright
Other

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