Secondary ions from hydrogen ion bombardment of metal surfaces

Journal Article · Fri Aug 01 04:00:00 EDT 1980 · J. Appl. Phys.; (United States)

DOI:https://doi.org/10.1063/1.328289· OSTI ID:5296889

McCaughan, D V; Sloane, R H; Geddes, J

The production of negative ions at metal surfaces under ion bombardment is of theoretical and practical interest. In this paper data for H/sup +/ and H/sup -/ production at clean and hydrogen-covered tungsten surfaces under H/sup +//sub n/ bombardment are given, and the data interpreted. In the experimental apparatus primary ion beams of H/sup +//sub n/ are impacted on a tungsten target, from which secondary H/sup +/ and H/sup -/ ions are emitted, and mass and energy are analyzed. It is found that the secondary H/sup +/ spectrum from H/sup +//sub n/ bombardment is a broad peak, reaching an E/sub max/ which is a function of the primary ion energy, independent of the state of hydrogen coverage of the tungsten surface. The H/sup -/ yield has a peak and tail distribution, the peak being a function of the degree of surface coverage. The mechanism whereby the high-energy peak arises and the amount of hydrogen trapped in the lattice is related to multiple scattering process in the target. The low-energy peak of H/sup -/ ions arises from surface atoms sputtered off the surface as H/sup -/ ions. A new theory explaining the secondary H/sup -/ production in terms of a two electron Auger process followed by resonant capture of an electron from a normally unoccupied state in the metal is presented.

• Research Organization: Royal Signals and Radar Establishment, Great Malvern, Worcs, United Kingdom
• OSTI ID: 5296889
• Journal Information: J. Appl. Phys.; (United States), Journal Name: J. Appl. Phys.; (United States) Vol. 51:8; ISSN JAPIA
• Country of Publication: United States
• Language: English

Related Subjects

640301* -- Atomic
Molecular & Chemical Physics-- Beams & their Reactions
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
CHARGED PARTICLES
COLLISIONS
ELEMENTS
EMISSION
ENERGY DEPENDENCE
ENERGY SPECTRA
HYDROGEN IONS
ION COLLISIONS
IONS
MASS SPECTROSCOPY
METALS
REFRACTORY METALS
SECONDARY EMISSION
SPECTRA
SPECTROSCOPY
SURFACES
TARGETS
TRANSITION ELEMENTS
TUNGSTEN