High-current density, high-brightness electron beams from large-area lanthanum hexaboride cathodes

Journal Article · Fri Apr 15 00:00:00 EDT 1988 · J. Appl. Phys.; (United States)

DOI:https://doi.org/10.1063/1.340990· OSTI ID:5268534

Loschialpo, P; Kapetanakos, C A

Large (approx.5 cm) diameter lanthanum hexaboride (LaB/sub 6/) cathodes operated at 10 kV have produced 1--5-..mu..s electron pulses with current density between 10 and 20 A/cm/sup 2/. Normalized beam brightness, B/sub n/ = I/(..pi beta gamma..epsilon)/sup 2/, approximately 3 x 10/sup 5/ A/cm/sup 2/ rad/sup 2/ has been consistently measured. To obtain this high-current density, the LaB/sub 6/ cathodes have been heated to temperatures between approx.1600 and 1800 /sup 0/C. Very uniform temperature profiles are obtained by applying a carefully tailored electron bombardment heating power distribution. These measurements have been made between pressure 10/sup -6/--10/sup -5/ Torr, i.e., under much less demanding vacuum conditions than that required by conventional dispenser-type cathodes.

• Research Organization: Advanced Beam Technologies Branch, Plasma Physics Division, Naval Research Laboratory, Washington, DC 20375
• OSTI ID: 5268534
• Journal Information: J. Appl. Phys.; (United States), Journal Name: J. Appl. Phys.; (United States) Vol. 63:8; 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
BEAM PRODUCTION
BEAMS
BORIDES
BORON COMPOUNDS
BRIGHTNESS
CATHODES
CURRENT DENSITY
DATA
ELECTRODES
ELECTRON BEAMS
ELECTRON EMISSION
ELECTRON SOURCES
EMISSION
EXPERIMENTAL DATA
FREE ELECTRON LASERS
INFORMATION
LANTHANUM BORIDES
LANTHANUM COMPOUNDS
LASERS
LEPTON BEAMS
NUMERICAL DATA
OPERATION
OPTICAL PROPERTIES
PARTICLE BEAMS
PARTICLE SOURCES
PHYSICAL PROPERTIES
RADIATION SOURCES
RARE EARTH COMPOUNDS
VERY HIGH TEMPERATURE