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Title: Generalization of the Child-Langmuir law to the alternate extraction of positive and negative ions

Abstract

Using a combined analytical and simulation approach, we investigate positive and negative ion extraction between two electrodes from an ion-ion plasma source. With a square voltage waveform applied to the electrodes, we obtain approximate analytical solutions for the time-averaged extracted current densities, which are given simply by: J{sub p}{sup ac}=[α−fL√((M{sub p})/(q{sub p}V{sub 0}) )]J{sub p}{sup dc}, and J{sub n}{sup ac}=[(1−α)−fL√((M{sub n})/(q{sub n}V{sub 0}) )]J{sub n}{sup dc}, where J{sup ac} is the time-averaged current density, α is the square waveform duty cycle, f is the frequency, L is the electrode gap length, M is the ion mass, q is the ion charge, V{sub 0} is the applied voltage amplitude, J{sup dc} is the dc extracted current density, and the subscripts p and n refer to positive and negative ions, respectively. In particular, if J{sup dc} is the dc space-charge limited current density, then these equations describe the square waveform generalization of the Child-Langmuir law.

Authors:
 [1]
  1. Laboratoire de Physique des Plasmas, CNRS, Sorbonne Universités, UPMC Univ Paris 06, Univ Paris-Sud, Ecole Polytechnique, 91128 Palaiseau (France)
Publication Date:
OSTI Identifier:
22407951
Resource Type:
Journal Article
Journal Name:
Physics of Plasmas
Additional Journal Information:
Journal Volume: 21; Journal Issue: 12; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 1070-664X
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; AMPLITUDES; ANALYTICAL SOLUTION; ANIONS; CURRENT DENSITY; ELECTRIC POTENTIAL; ELECTRODES; EQUATIONS; LANGMUIR PROBE; PLASMA; PLASMA SIMULATION; SPACE CHARGE; WAVE FORMS

Citation Formats

Lafleur, T., E-mail: trevor.lafleur@lpp.polytechnique.fr, ONERA-The French Aerospace Lab, 91120 Palaiseau, and Aanesland, A. Generalization of the Child-Langmuir law to the alternate extraction of positive and negative ions. United States: N. p., 2014. Web. doi:10.1063/1.4903850.
Lafleur, T., E-mail: trevor.lafleur@lpp.polytechnique.fr, ONERA-The French Aerospace Lab, 91120 Palaiseau, & Aanesland, A. Generalization of the Child-Langmuir law to the alternate extraction of positive and negative ions. United States. https://doi.org/10.1063/1.4903850
Lafleur, T., E-mail: trevor.lafleur@lpp.polytechnique.fr, ONERA-The French Aerospace Lab, 91120 Palaiseau, and Aanesland, A. 2014. "Generalization of the Child-Langmuir law to the alternate extraction of positive and negative ions". United States. https://doi.org/10.1063/1.4903850.
@article{osti_22407951,
title = {Generalization of the Child-Langmuir law to the alternate extraction of positive and negative ions},
author = {Lafleur, T., E-mail: trevor.lafleur@lpp.polytechnique.fr and ONERA-The French Aerospace Lab, 91120 Palaiseau and Aanesland, A.},
abstractNote = {Using a combined analytical and simulation approach, we investigate positive and negative ion extraction between two electrodes from an ion-ion plasma source. With a square voltage waveform applied to the electrodes, we obtain approximate analytical solutions for the time-averaged extracted current densities, which are given simply by: J{sub p}{sup ac}=[α−fL√((M{sub p})/(q{sub p}V{sub 0}) )]J{sub p}{sup dc}, and J{sub n}{sup ac}=[(1−α)−fL√((M{sub n})/(q{sub n}V{sub 0}) )]J{sub n}{sup dc}, where J{sup ac} is the time-averaged current density, α is the square waveform duty cycle, f is the frequency, L is the electrode gap length, M is the ion mass, q is the ion charge, V{sub 0} is the applied voltage amplitude, J{sup dc} is the dc extracted current density, and the subscripts p and n refer to positive and negative ions, respectively. In particular, if J{sup dc} is the dc space-charge limited current density, then these equations describe the square waveform generalization of the Child-Langmuir law.},
doi = {10.1063/1.4903850},
url = {https://www.osti.gov/biblio/22407951}, journal = {Physics of Plasmas},
issn = {1070-664X},
number = 12,
volume = 21,
place = {United States},
year = {Mon Dec 15 00:00:00 EST 2014},
month = {Mon Dec 15 00:00:00 EST 2014}
}