Surface production of H[sub [minus]] ions by backscattering of H[sup +]and H[sup +][sub 2] ions in the 3--50 eV ion energy range

Conference · Mon Oct 05 04:00:00 EDT 1992 · AIP Conference Proceedings (American Institute of Physics); (United States)

OSTI ID:6934985

Isenberg, J D; Kwon, H J; Seidl, M ^[1]

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1. Stevens Institute of Technology, Hoboken, NJ (United States)

Results of measurements of the total yield of H[sub [minus]] ions due to surface conversion of H[sup +] and H[sub 2][sup +] ions at low work function surfaces are presented. A low energy (3--50 eV) ion beam strikes the target at normal incidence. All secondary charged particles are collected. Calculations of the theoretical negative ion yield as a function of incident perpendicular energy have been modified to include energy and particle losses due to scattering. The scattering is modeled using TRIM calculations of particle and energy reflection coefficients. A cosine distribution in scattering angle has been assumed. The surface investigated was polycrystalline molybdenum, cesiated by vapor deposition. The work functions were determined by measurements of photoemission threshold of these surfaces. H[sup [minus]] and electron yields were determined by taking the ratio of the secondary charged particle currents to the proton current to the target. Secondary electrons were suppressed by a magnetic field. H[sup [minus]] and electron yields of order 20% per incident nucleon were obtained.

• OSTI ID: 6934985
• Report Number(s): CONF-921145--
• Conference Information: Journal Name: AIP Conference Proceedings (American Institute of Physics); (United States) Journal Volume: 287:1
• Country of Publication: United States
• Language: English

Related Subjects

661220* -- Particle Beam Production & Handling
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ANIONS
BACKSCATTERING
BARYONS
CATIONS
CHARGED PARTICLES
ELEMENTARY PARTICLES
ELEMENTS
EMISSION
ENERGY RANGE
EV RANGE
EV RANGE 01-10
EV RANGE 10-100
FERMIONS
FUNCTIONS
HADRONS
HYDROGEN IONS
HYDROGEN IONS 1 MINUS
HYDROGEN IONS 1 PLUS
ION SOURCES
IONIZATION
IONS
METALS
MOLYBDENUM
NUCLEONS
PROTONS
SCATTERING
SECONDARY EMISSION
SURFACE IONIZATION
TRANSITION ELEMENTS
Ta
Targets-- (1992-)
WORK FUNCTIONS