Optimization of H/sup -/ production from a small multicusp ion source

Journal Article · Sat Apr 01 04:00:00 EST 1989 · Rev. Sci. Instrum.; (United States)

DOI:https://doi.org/10.1063/1.1140359· OSTI ID:6343405

Leung, K N; Hauck, C A; Kunkel, W B; Walther, S R

A small multicusp source has been developed to generate volume-produced H/sup -/ ion beams in pulsed operation. To obtain high H/sup -/ current densities (J/sup -/>250 mA/cm/sup 2/), this source requires relatively high gas pressure and high discharge power. Experiments have been conducted to improve the arc and gas efficiencies, the beam pulse shape, and the H/sup -/ to electron ratio in the extracted beam by optimizing the filter magnetic field, the thickness and axial position of the extraction aperture in the plasma electrode, and by mixing xenon or other elements with hydrogen in the discharge. The biggest improvement is achieved by adding cesium to the source, resulting in a fivefold increase in the extractable H/sup -/ current and a substantial drop in the e/H/sup -/ ratio. In order to improve the lifetime of the cathode, both filament and coaxial type LaB/sub 6/ cathodes have been developed and have been operated successfully in this H/sup -/ source.

• Research Organization: Accelerator and Fusion Research Division, Lawrence Berkeley Laboratory, 1 Cyclotron Road, Berkeley, California 94720
• OSTI ID: 6343405
• Journal Information: Rev. Sci. Instrum.; (United States), Journal Name: Rev. Sci. Instrum.; (United States) Vol. 60:4; ISSN RSINA
• Country of Publication: United States
• Language: English

Related Subjects

640301* -- Atomic
Molecular & Chemical Physics-- Beams & their Reactions
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ALKALI METALS
ANIONS
BEAM CURRENTS
CESIUM
CHARGED PARTICLES
CURRENTS
CUSPED GEOMETRIES
ELECTRIC DISCHARGES
ELEMENTS
HYDROGEN IONS
HYDROGEN IONS 1 MINUS
ION SOURCES
IONS
MAGNETIC FIELD CONFIGURATIONS
METALS
OPEN CONFIGURATIONS
OPTIMIZATION