Work-function dependence of above-surface neutralization of multicharged ions

Journal Article · Wed Dec 01 04:00:00 EST 1993 · Physical Review A; (United States)

DOI:https://doi.org/10.1103/PhysRevA.48.4479· OSTI ID:5680553

Meyer, F W; Folkerts, L; Hughes, I G; Overbury, S H; Zehner, D M; Zeijlmans van Emmichoven, P A ^[1]; Burgdoerfer, J ^[2]

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1. Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6372 (United States)
2. Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6377 (United States) Department of Physics, University of Tennessee, Knoxville, Tennessee 37996-1200 (United States)

Measurements have been made of projectile [ital K]-Auger-electron emission during interactions of 60-keV N[sup 6+] ions grazingly incident on a Au(011) single crystal whose work function was modified by submonolayer deposits of Cs. [ital K] Auger spectra were obtained for incidence angles in the range 0.3[degree]--5[degree], using clean, as well as cesiated, Au surfaces whose work function had been reduced by as much as 3.3 eV. For incidence angles smaller than 5[degree], an enhancement on the above-surface [ital K] Auger component, relative to that observed for clean'' Au, could be discerned with decreasing surface work function, which appears to saturate below 0.7[degree] (corresponding to an inverse perpendicular velocity of about 200 a.u.[sup [minus]1]) at approximately 30--35 %. The experimental results are compared with modeling studies of the work-function dependence of above-surface neutralization and projectile [ital K] Auger emission, using a simulation based on the classical over-the-barrier model that was modified to treat the case of a two-component'' surface. The simulation results agree qualitatively with the experimental results up to [ital v][sub [perpendicular]][sup [minus]1]=200. At higher inverse perpendicular velocities, the simulated enhancement continues to increase and exceeds the clean Au result by more than a factor of 2 at [ital v][sub [perpendicular]][sup [minus]1]=1000. Speculations about possible reasons for this discrepancy will be presented.

• DOE Contract Number: AC05-84OR21400
• OSTI ID: 5680553
• Journal Information: Physical Review A; (United States), Journal Name: Physical Review A; (United States) Vol. 48:6; 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
ATOMIC IONS
AUGER EFFECT
BEAM NEUTRALIZATION
CHARGED PARTICLES
COLLISIONS
CORRELATIONS
CRYSTALS
ELECTRONIC STRUCTURE
ELEMENTS
FUNCTIONS
GOLD
ION COLLISIONS
IONS
K SHELL
METALS
MONOCRYSTALS
MULTICHARGED IONS
NITROGEN IONS
PROJECTILES
TRANSITION ELEMENTS
WORK FUNCTIONS