Accession Number : AD0687630

Title :   METASTABLE ATOMS AND MOLECULES. III. METASTABLE IMPACTS ON SURFACES WITH VARIOUS WORK FUNCTIONS,

Corporate Author : LOCKHEED MISSILES AND SPACE CO PALO ALTO CALIF LOCKHEED RESEARCH LAB

Personal Author(s) : Varney,R. N.

Report Date : 09 MAY 1968

Pagination or Media Count : 5

Abstract : Surfaces of atomically clean tungsten, with work function 4.5 eV, tungsten oxidized with a monolayer of oxide and having a work function 6.6 eV, and tungsten coated with BaO with a work function probably under 2 eV were hit by metastable atoms or molecules of Ar, Xe, N2, and H2. The emission of secondary electrons by metastable atoms and the surface ionization of the atomic metastables were shown to follow the expected dependency on the work function. The N2 molecular metastables were weakly surface ionized as N2(+) on the oxidized tungsten but not on the surfaces of lower work function. Secondary electron emission either did not occur at all or was obscured by the large emission of CN(-) negative ions. No CN(-) emission nor electron emission was observed on the W-O surface. Metastables of H2 dissociated on the clean and the oxidized surfaces. On the clean surface, one atom became H(2p) and gave out Lyman alpha radiation. On the W-O surface, one of the H atoms became a proton and no Lyman alpha radiation was produced. No other ion emission than H(+) occurred. (Author)

Descriptors :   (*TUNGSTEN, WORK FUNCTIONS), (*MOLECULAR BEAMS, INTERACTIONS), IONIZATION POTENTIALS, ELECTRON TRANSITIONS, ARGON, XENON, HYDROGEN, NITROGEN, TUNGSTEN COMPOUNDS, OXIDES, SURFACE PROPERTIES

Subject Categories : Physical Chemistry

Distribution Statement : APPROVED FOR PUBLIC RELEASE