Results 241 to 250 of about 1,131,290 (276)
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Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences, 1979
During the last few years, improvements in ionization techniques have revived interest in negative ion mass spectrometry and its applications. Ion sources that operate at pressures of up to 1 Torr (133 Pa) produce high concentrations of low energy electrons which may react directly with suitable sample molecules to form negative molecular ...
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During the last few years, improvements in ionization techniques have revived interest in negative ion mass spectrometry and its applications. Ion sources that operate at pressures of up to 1 Torr (133 Pa) produce high concentrations of low energy electrons which may react directly with suitable sample molecules to form negative molecular ...
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Ion–Molecule Reactions of Negative Ions. I. Negative Ions of Sulfur
The Journal of Chemical Physics, 1968Negative ions from carbonyl sulfide and carbon disulfide have been studied in a time-of-flight mass spectrometer. The principal ions formed by dissociative resonance electron capture in carbonyl sulfide are S− and O−. Those from carbon disulfide are S− and CS−.
John G. Dillard, J. L. Franklin
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Autodetachment of negative ions
Physical Review A, 1991The autodetachment of 1s2s2p 4p0 in He- and nsnp 2 4P(e) in Be- (n = 2), Mg- (n = 3), and Ca- (n = 4) is calculated using an extension to continum processes of the multiconfiguration Hartree-Fock method. The main interest is to investigate the processes giving rise to long-lived, metastable states in negative ions. In He- and Be- our results agree with
, Brage, , Fischer
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Annual Review of Physical Chemistry, 1979
This article surveys experimental methods for studying the interactions of small, free atomic and molecular negative ions with radiation, and the structural information that can be obtained from such studies. The subject is an old one, having its origins some 40 years ago when Wildt (1) recognized that Hwas a major source of opacity in the solar ...
R R Corderman, W C Lineberger
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This article surveys experimental methods for studying the interactions of small, free atomic and molecular negative ions with radiation, and the structural information that can be obtained from such studies. The subject is an old one, having its origins some 40 years ago when Wildt (1) recognized that Hwas a major source of opacity in the solar ...
R R Corderman, W C Lineberger
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Applied Physics Letters, 1974
The principle of detailed balance is used to show that at a maximum in an electron excitation cross section, due to a very-short-lived negative ion resonance (10−14–10−16 sec), the electron deexcitation cross section can be significantly smaller than the electron excitation cross section. Using experimental estimates of the various necessary parameters,
David E. Golden, Stephan Ormonde
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The principle of detailed balance is used to show that at a maximum in an electron excitation cross section, due to a very-short-lived negative ion resonance (10−14–10−16 sec), the electron deexcitation cross section can be significantly smaller than the electron excitation cross section. Using experimental estimates of the various necessary parameters,
David E. Golden, Stephan Ormonde
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Physical Review, 1964
Results of Hartree-Fock calculations on the ions of ${\mathrm{Li}}^{\ensuremath{-}}$, ${\mathrm{B}}^{\ensuremath{-}}$, ${\mathrm{C}}^{\ensuremath{-}}$, ${\mathrm{N}}^{\ensuremath{-}}$, ${\mathrm{O}}^{\ensuremath{-}}$, ${\mathrm{F}}^{\ensuremath{-}}$, ${\mathrm{N}}^{\ensuremath{-}\ensuremath{-}}$, ${\mathrm{O}}^{\ensuremath{-}\ensuremath{-}}$ in states ...
Enrico Clementi, A. D. McLean
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Results of Hartree-Fock calculations on the ions of ${\mathrm{Li}}^{\ensuremath{-}}$, ${\mathrm{B}}^{\ensuremath{-}}$, ${\mathrm{C}}^{\ensuremath{-}}$, ${\mathrm{N}}^{\ensuremath{-}}$, ${\mathrm{O}}^{\ensuremath{-}}$, ${\mathrm{F}}^{\ensuremath{-}}$, ${\mathrm{N}}^{\ensuremath{-}\ensuremath{-}}$, ${\mathrm{O}}^{\ensuremath{-}\ensuremath{-}}$ in states ...
Enrico Clementi, A. D. McLean
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The Physics of Fluids, 1975
In a plasma composed of negative (SF−6) ions, positive (Ar+) ions, and electrons (with ne/n+ reducible to less than 10−3) a fast ion mode (vph≈9Cs), due to the out-of-phase motion between positive and negative ions, is observed with reduced spatial attenuation. This fast ion mode exhibits spatial growth in the presence of a fast ion beam.
A. Y. Wong, D. L. Mamas, D. Arnush
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In a plasma composed of negative (SF−6) ions, positive (Ar+) ions, and electrons (with ne/n+ reducible to less than 10−3) a fast ion mode (vph≈9Cs), due to the out-of-phase motion between positive and negative ions, is observed with reduced spatial attenuation. This fast ion mode exhibits spatial growth in the presence of a fast ion beam.
A. Y. Wong, D. L. Mamas, D. Arnush
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Physical Review, 1958
Negative helium ions have been produced with an ion source previously used for negative hydrogen ion production. Positive helium ions pass through a charge-exchange tube filled with hydrogen gas and the resulting negative ions are magnetically analyzed.
P. M. Windham +2 more
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Negative helium ions have been produced with an ion source previously used for negative hydrogen ion production. Positive helium ions pass through a charge-exchange tube filled with hydrogen gas and the resulting negative ions are magnetically analyzed.
P. M. Windham +2 more
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The Journal of Chemical Physics, 1959
A semiempirical method is proposed for the computation of the electron affinities of negative atomic ions by extrapolation from the ionization potentials of the corresponding isoelectronic sequences. The method is based on a formula which can be justified on physical grounds and of which at least two parameters have direct physical interpretation.
H. R. Johnson, F. Rohrlich
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A semiempirical method is proposed for the computation of the electron affinities of negative atomic ions by extrapolation from the ionization potentials of the corresponding isoelectronic sequences. The method is based on a formula which can be justified on physical grounds and of which at least two parameters have direct physical interpretation.
H. R. Johnson, F. Rohrlich
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MRS Proceedings, 1994
AbstractNegative-ion implantation is a promising technique for forthcoming ULSI (more than 256 M bits) fabrication and TFT (for color LCD) fabrication, since the surface charging voltage of insulated electrodes or insulators implanted by negative ions is found to saturate within so few as several volts, no breakdown of insulators would be expected ...
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AbstractNegative-ion implantation is a promising technique for forthcoming ULSI (more than 256 M bits) fabrication and TFT (for color LCD) fabrication, since the surface charging voltage of insulated electrodes or insulators implanted by negative ions is found to saturate within so few as several volts, no breakdown of insulators would be expected ...
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