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Title: Influence of trapped electrons on the time-independent states of a negatively biased single-ended Q machine

Abstract

Measurements of basic plasma parameters in a low-density single-ended Q machine with a negatively biased cold plate are compared with pertinent predictions of time-independent collisionless plane-diode theory. As was also found in particle simulations [Phys. Fluids B {bold 3}, 244 (1991)] and previous experiments, theory and experiment agree well if space-charge conditions near the hot-plate surface are electron rich, in which case the potential distributions are monotonically decreasing. For ion-rich conditions, however, where the potential distributions exhibit a single maximum located in front of the hot plate, the plasma properties are found to depend very sensitively on the amount and distribution of the electrons trapped in the region of positive potential. In this regime, the experimental findings agree very well with a theoretical model in which a certain amount of trapped electrons is assumed. {copyright} {ital 1996 American Institute of Physics.}

Authors:
; ; ; ;  [1]
  1. Plasma and Energy Physics Group, Institute for Theoretical Physics, University of Innsbruck, A-6020 Innsbruck (Austria)
Publication Date:
OSTI Identifier:
279748
Resource Type:
Journal Article
Journal Name:
Physics of Plasmas
Additional Journal Information:
Journal Volume: 3; Journal Issue: 4; Other Information: PBD: Apr 1996
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION; Q DEVICES; COLLISIONLESS PLASMA; KINETIC EQUATIONS; PLASMA DIAGNOSTICS; PLASMA POTENTIAL; SPACE CHARGE; TRAPPED ELECTRONS

Citation Formats

Oertl, M, Kuhn, S, Krumm, P, Schupfer, N, and Crystal, T L. Influence of trapped electrons on the time-independent states of a negatively biased single-ended Q machine. United States: N. p., 1996. Web. doi:10.1063/1.871743.
Oertl, M, Kuhn, S, Krumm, P, Schupfer, N, & Crystal, T L. Influence of trapped electrons on the time-independent states of a negatively biased single-ended Q machine. United States. doi:10.1063/1.871743.
Oertl, M, Kuhn, S, Krumm, P, Schupfer, N, and Crystal, T L. Mon . "Influence of trapped electrons on the time-independent states of a negatively biased single-ended Q machine". United States. doi:10.1063/1.871743.
@article{osti_279748,
title = {Influence of trapped electrons on the time-independent states of a negatively biased single-ended Q machine},
author = {Oertl, M and Kuhn, S and Krumm, P and Schupfer, N and Crystal, T L},
abstractNote = {Measurements of basic plasma parameters in a low-density single-ended Q machine with a negatively biased cold plate are compared with pertinent predictions of time-independent collisionless plane-diode theory. As was also found in particle simulations [Phys. Fluids B {bold 3}, 244 (1991)] and previous experiments, theory and experiment agree well if space-charge conditions near the hot-plate surface are electron rich, in which case the potential distributions are monotonically decreasing. For ion-rich conditions, however, where the potential distributions exhibit a single maximum located in front of the hot plate, the plasma properties are found to depend very sensitively on the amount and distribution of the electrons trapped in the region of positive potential. In this regime, the experimental findings agree very well with a theoretical model in which a certain amount of trapped electrons is assumed. {copyright} {ital 1996 American Institute of Physics.}},
doi = {10.1063/1.871743},
journal = {Physics of Plasmas},
number = 4,
volume = 3,
place = {United States},
year = {1996},
month = {4}
}