Thermionic cathode electron gun for high current densities

Journal Article · Sat Aug 01 00:00:00 EDT 1987 · IEEE Trans. Plasma Sci.; (United States)

DOI:https://doi.org/10.1109/TPS.1987.4316719· OSTI ID:5884440

Herniter, M E; Getty, W D

An electron gun using lanthanum hexaboride (LaB/sub 6/) as a cathode material is being studied for use as a robust thermionic emitter at high cathode current densities. It has a standard planar cathode, Pierce-type electron gun design with a space-charge-limited perveance of 3.2 x 10/sup -6/ A/V/sup 3/2/. Thus far it has been operated up to 36 kV in the space-charge-limited regime. The cathode is heated by electron bombardment and radiation from an auxiliary tungsten filament. The total heating requirement is found to be 202 W/cm/sup 2/ of cathode area at a cathode temperature of 1626/sup 0/C. These observations are found to be in reasonable agreement with a thermal steady-state power balance model. Beam current distribution measurements are made with a movable collector and Faraday cup, and are found to be in agreement with an electron-gun computer code. The cathode temperature distribution is also measured.

• Research Organization: Dept. of Electrical Engineering and Computer Science, Univ. of Michigan, Ann Arbor, MI 48109
• OSTI ID: 5884440
• Journal Information: IEEE Trans. Plasma Sci.; (United States), Vol. PS-15:4
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ELECTRON GUNS
BEAM CURRENTS
THERMIONIC DIODES
CURRENT DENSITY
ELECTRON BEAM ION SOURCES
ELECTRON TEMPERATURE
LANTHANUM BORIDES
SPACE CHARGE
TUNGSTEN
BORIDES
BORON COMPOUNDS
CURRENTS
DIODE TUBES
ELECTRON TUBES
ELEMENTS
ION SOURCES
LANTHANUM COMPOUNDS
METALS
RARE EARTH COMPOUNDS
THERMIONIC TUBES
TRANSITION ELEMENTS
640301* - Atomic
Molecular & Chemical Physics- Beams & their Reactions
700103 - Fusion Energy- Plasma Research- Kinetics