Results 261 to 270 of about 427,941 (305)

Numerical analysis of negative ion temperature in a negative ion source

Review of Scientific Instruments, 2004
To understand the origin of the two energy groups of volume produced H− ions observed in the multicusp, hybrid-type H− ion source (Camembert III), numerical analysis by the three-dimensional Monte Carlo simulation code has been done. Realistic multicusp geometry and the electric field near the filament are taken into account in the model.
A. Hatayama, K. Makino, T. Sakurabayasi, K. Miyamoto, M. Ogasawara, M. Bacal   +5 more
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Ion wake fields in a plasma with negative ions

Physical Review E, 1994
Ion wake fields in a quasineutral plasma that contains negative ions are theoretically examined using two independent approaches. The two analyses described here are based on the initial assumption that a driving ion bunch may be injected into either a drifting plasma or a stationary plasma.
, Kim, , Yi, , Amin, , Lonngren
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Photodetachment of Positronium Negative Ions

Physical Review Letters, 2011
Photodetachment of the positronium negative ion, a bound state of one positron and two electrons, has been observed. Development of a method to produce the ions efficiently using a Na coated tungsten surface has enabled the first observation of the photodetachment. The obtained lower limit of the photodetachment cross section for the wavelength of 1064
K, Michishio, T, Tachibana, H, Terabe, A, Igarashi, K, Wada, T, Kuga, A, Yagishita, T, Hyodo, Y, Nagashima   +8 more
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Perfluoroadamantane and Its Negative Ion

The Journal of Physical Chemistry A, 2005
As a general rule, saturated hydrocarbons are unable to bind an electron, i.e., their electron affinities are negative, but the corresponding perfluorinated molecules can have significant electron affinities, especially in the case of branched and ring systems.
Qian-shu, Li, Xue-jun, Feng, Yaoming, Xie, Henry F, Schaefer   +3 more
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Regularities of Negative Ion Resonances

Topical Meeting on Multiple Excitations of Atoms, 1986
The effects of electron correlation in atomic and molecular systems are perhaps most pronounced in negative ions. No long-range Coulomb field is present to bind an additional electron to a parent state of a neutral atom. The stability of a negative ion state is thus usually attributed to one of two alternative mechanisms, both of which invoke electron ...
Charles W. Clark, Stephen J. Buckman
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Excited Negative Ions and Molecules and Negative Ion Production

1992
Abstract : Research has been performed to determine fundamental properties of negative ions; decay mechanisms and products of molecular Rydberg states; and mechanisms affecting H- production in ion source discharges. Experiments were performed on both stable and metastable states of Ca-, Cs-, He 2-, and WO3-; on the dissociative decay of Rydberg states
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Negative Ion Formation and Negative Ion-Molecule Reactions in Cyclopentadiene

The Journal of Chemical Physics, 1972
The low pressure source of a Bendix time-of-flight mass spectrometer has been employed for a study of positive and negative ion formation in cyclopentadiene (C5H6). Six negative ions in the mass spectrum of C5H6 have been investigated and particular attention has been paid to the cyclopentadienyl negative ion (C5H5-).
A. di Domenico, P. W. Harland, J. L. Franklin   +2 more
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Negative-ion sources for ion implantation

Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 1991
Abstract The development of negative-ion sources has now reached the state where they can be considered for implanter applications. In the following paper a conceptual negative-ion source is described, based on production by dissociative attachment in the plasma.
A.J.T. Holmes, G. Proudfoot
openaire   +1 more source

Physics with Negative Ions in Ion Traps

Physica Scripta, 1988
Photodetachment experiments with atomic and molecular negative ions have been carried out using a Penning ion trap. The experiments provide new information about photodetachment in the presence of a static magnetic field and about photodetachment in the presence of a strong laser field.
D J Larson, C J Edge, R E Elmquist, N B Mansour, R Trainham   +4 more
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A negative ion survey; towards the completion of the periodic table of the negative ions

Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 1997
Abstract The negative ion properties of many of the elements of the periodic table have been known for some years, however, there were some 36 elements for which conclusive experimental evidence for the existence of a stable negative ion had not been found.
M-J. Nadeau, M.A. Garwan, X-L. Zhao, A.E. Litherland   +3 more
openaire   +1 more source