The effect of work function reduction on above-surface neutralization of multicharged ions

Journal Article · Sat May 01 04:00:00 EDT 1993 · Bulletin of the American Physical Society

OSTI ID:281587

Meyer, F W; Folkerts, L; Hughes, I G ^[1]

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1. Oak Ridge National Laboratory, TN (United States); and others

The critical distance above the surface at which conduction band electrons can start to neutralize incident multicharged projectiles by classical overbarrier transitions is inversely proportional to the metal work function. By varying the amount of Cs coverage on a Au single crystal target between 0 and 1 monolayers, we have been able to verify an up to 3.3 eV decrease of the surface work function, corresponding to more than a factor of two decrease relative to that tabulated for clean Au. This change should result in more than doubling the above-surface interaction time. At larger above-surface distances, however, the electron capture most likely occurs into higher principal quantum numbers of the projectile. The subsequent deexcitation cascade by which inner shells of the projectiles are populated may thus require more time. We have investigated the overall effect that lowering the work function has on the above-surface component of projectile K-Auger electron emission for grazing incidence N{sup 6+} ions interacting with cesiated Au single crystals. We will present results showing that an enhancement of this component is indeed observed, and that it is strongly dependent on incidence angle.

• DOE Contract Number: AC05-84OR21400
• OSTI ID: 281587
• Report Number(s): CONF-9305421--
• Journal Information: Bulletin of the American Physical Society, Journal Name: Bulletin of the American Physical Society Journal Issue: 3 Vol. 38; ISSN 0003-0503; ISSN BAPSA6
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
ELECTRON CAPTURE
GOLD
ION COLLISIONS
MULTICHARGED IONS
NITROGEN IONS
SURFACES
WORK FUNCTIONS