Deexcitation of helium 2 [sup 3][ital S], 2 [sup 1][ital S], and 2 [sup 3][ital P] atoms at Ar and Xe films

Journal Article · Wed Jun 01 04:00:00 EDT 1994 · Physical Review A; (United States)

DOI:https://doi.org/10.1103/PhysRevA.49.4703· OSTI ID:7307303

Oro, D M; Soletsky, P A; Zhang, X; Dunning, F B; Walters, G K ^[1]

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1. Department of Physics and the Rice Quantum Institute, Rice University, P.O. Box 1892, Houston, Texas 77251 (United States)

Measurements of ejected electron energy distributions are used in conjunction with electron spin labeling techniques to probe the mechanisms by which He(2 [sup 3][ital S]), He(2 [sup 1][ital S]), and He(2 [sup 3][ital P]) atoms are deexcited at Ar and Xe films adsorbed on a cooled Cu(100) substrate. The data for both surfaces contain features similar to those observed in gas-phase Penning ionization, indicating that ejection results, in part, from Auger deexcitation, i.e., surface Penning ionization. For Xe, however, additional features are observed that can be attributed to resonance ionization of an incident excited atom followed by neutralization of the resulting He[sup +] ion through an interaction that involves neighboring Xe atoms in the film. Indeed, the Xe data provide an exceptional example of a surface at which Auger deexcitation and resonance ionization occur in parallel with one another, with a branching ratio that changes significantly as the internal energy of the incident atoms increases. The ejected electron yield from both Ar and Xe films is substantially higher than for clean Cu(100), indicating that such films might form the basis of an efficient thermal-energy helium metastable-atom detector.

• OSTI ID: 7307303
• Journal Information: Physical Review A; (United States), Journal Name: Physical Review A; (United States) Vol. 49:6; ISSN 1050-2947; ISSN PLRAAN
• Country of Publication: United States
• Language: English

Related Subjects

665300* -- Interactions Between Beams & Condensed Matter-- (1992-)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ARGON
ATOM COLLISIONS
AUGER EFFECT
COLLISIONS
COPPER
DE-EXCITATION
ELECTRON EMISSION
ELEMENTS
EMISSION
ENERGY SPECTRA
ENERGY-LEVEL TRANSITIONS
FILMS
FLUIDS
GASES
HELIUM
IONIZATION
METALS
NONMETALS
ORIENTATION
RARE GASES
SPECTRA
SPIN ORIENTATION
SUBSTRATES
TRANSITION ELEMENTS
XENON