Fluid Model Analysis of the Distribution of the Negative Ion Density before the Extraction from a Tandem Type of a Plasma Source

This paper reports the results of computations to obtain the spatial distributions of the charged particles in a bounded active plasma dominated by negative ions. Using the fluid model with a constant collision frequency for electrons, positive ions and negative ions the cases of both detachment-dominated gases (such as oxygen) and recombination-dominated gases (such as chlorine) are examined. It is concluded that it is valid to use a Boltzmann relation ne = ne0exp(eV/kT) for the electrons of density ne, where the temperature T is approximately the electron temperature Te, and that the density nn of the negative ions at low pressures obeys nn = nn0exp(eV/kTn), where Tn is the negative-ion temperature. However, at high pressure in detachment-dominated gases where the ratio of negative-ion density to electron density is constant and greater than unity, and when the attachment rate is larger than the ionization rate, the negative ions are distributed with the same effective temperature as the electrons. In all other cases there is no simple relationship. Thus to put nn/ne = const, nn = ne0exp(eV/kTe) and nn = nn0exp(eV/kTn) simultaneously is mathematically inconsistent and physically unsound. Accordingly, expressions deduced for ambipolar diffusion coefficients based on these assumptions have no validity. The correct expressions for the situation where nn/ne = const are obtained without invoking a Boltzmann relation for the negative ions.

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Grid bias effect upon the negative ion density in a tandem plasma source

Thin Solid Films ◽

10.1016/j.tsf.2005.08.058 ◽

2006 ◽

Vol 506-507 ◽

pp. 575-578 ◽

Cited By ~ 1

Author(s):

H. Takahashi ◽

T. Kasuya ◽

M. Wada

Keyword(s):

Plasma Source ◽

Negative Ion ◽

Bias Effect ◽

Ion Density

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Positive Corona and Atmospheric Negative Ion Density under Repetitive Impulse Conditions

IEEE Transactions on Industry Applications ◽

10.1109/tia.1987.4505019 ◽

1987 ◽

Vol IA-23 (6) ◽

pp. 990-994 ◽

Cited By ~ 1

Author(s):

Norman L. Allen ◽

Gerard Berger ◽

Derek Dring

Keyword(s):

Negative Ion ◽

Ion Density

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Comparative studies of the laser Thomson scattering and Langmuir probe methods for measurements of negative ion density in a glow discharge plasma

Plasma Sources Science and Technology ◽

10.1088/0963-0252/12/3/314 ◽

2003 ◽

Vol 12 (3) ◽

pp. 403-406 ◽

Cited By ~ 21

Author(s):

M Noguchi ◽

T Hirao ◽

M Shindo ◽

K Sakurauchi ◽

Y Yamagata ◽

...

Keyword(s):

Glow Discharge ◽

Comparative Studies ◽

Langmuir Probe ◽

Discharge Plasma ◽

Thomson Scattering ◽

Negative Ion ◽

Glow Discharge Plasma ◽

Ion Density

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A New Negative Ion Plasma Source for Material Processing

IEEE Conference Record - Abstracts. 2005 IEEE International Conference on Plasma Science ◽

10.1109/plasma.2005.359141 ◽

2005 ◽

Author(s):

Kazuya Fujiwara ◽

Masakatsu Endo ◽

Yasushi Ikeda ◽

Haruo Shindo

Keyword(s):

Material Processing ◽

Plasma Source ◽

Negative Ion ◽

Ion Plasma

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Effects of Negative Ion Density Control on Statistical Three Lags of Positive Impulse Corona in Dry Air

IEEJ Transactions on Fundamentals and Materials ◽

10.1541/ieejfms1990.119.4_451 ◽

1999 ◽

Vol 119 (4) ◽

pp. 451-457 ◽

Cited By ~ 1

Author(s):

Jian-bo Yang ◽

Hiroyasu Katase ◽

Tatsuya Mori ◽

Yasuji Izawa ◽

Kiyoto Nishijima

Keyword(s):

Negative Ion ◽

Ion Density ◽

Dry Air ◽

Density Control

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Experimental evidence for the role of ions in particle nucleation under atmospheric conditions

Proceedings of The Royal Society A Mathematical Physical and Engineering Sciences ◽

10.1098/rspa.2006.1773 ◽

2006 ◽

Vol 463 (2078) ◽

pp. 385-396 ◽

Cited By ~ 116

Author(s):

Henrik Svensmark ◽

Jens Olaf P Pedersen ◽

Nigel D Marsh ◽

Martin B Enghoff ◽

Ulrik I Uggerhøj

Keyword(s):

Sulphur Dioxide ◽

Aerosol Particles ◽

Experimental Studies ◽

Negative Ion ◽

Cloud Formation ◽

Particle Nucleation ◽

Atmospheric Conditions ◽

Ion Density ◽

Stable Clusters

Experimental studies of aerosol nucleation in air, containing trace amounts of ozone, sulphur dioxide and water vapour at concentrations relevant for the Earth's atmosphere, are reported. The production of new aerosol particles is found to be proportional to the negative ion density and yields nucleation rates of the order of 0.1–1 cm −3 s −1 . This suggests that the ions are active in generating an atmospheric reservoir of small thermodynamically stable clusters, which are important for nucleation processes in the atmosphere and ultimately for cloud formation.

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