Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1678245 | Ultramicroscopy | 2009 | 5 Pages |
Abstract
High detection efficiency combined with spatial resolution on a nm-scale makes the field ionization process a promising candidate for spatially resolved neutral particles detection. The effective cross-sectional area Ïeff can serve as a measure for the effectiveness of such a field ion detector. In the present contribution, we combine quantum-mechanical calculations of the field-modified electron density distribution near the tungsten tip surface and of the resulting local field distributions, performed using the functional integration method, with a classical treatment of the atom trajectories approaching the tip in order to calculate the Ïeff values for ionization of free He atoms over an apex of a tungsten field emitter tip. The calculated values are compared with experimental data for supersonic He atomic beams at two different temperatures 95 and 298Â K.
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Physical Sciences and Engineering
Materials Science
Nanotechnology
Authors
B. Holst, J. Piskur, P.P. Kostrobiy, B.M. Markovych, Y. Suchorski,