High-Current Density, High-Brightness Electron Beams from Large-Area Lanthanum Hexaboride Cathodes.
Abstract
Large (approx. 5 cm) diameter lanthanum hexaboride (LaB6) cathodes operated at 10 kV have produced 1-5 micro electron pulses with current density between 10 and 20 A/sq. cm. Normalized beam brightness, has been consistently measured. To obtain this high current density, the LaB6 cathodes have been heated to temperatures between approx 1600 - 1800 C. Very uniform temperature profiles are obtained by applying a carefully tailored electron bombardment heating power distribution. These measurements have been made between pressure .000001 to .00001 Torr, i.e., under much less demanding vacuum conditions than that required by conventional dispenser type cathodes. Keywords: Beam quality, Cathodes, Brightness.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 13, 1987
- Accession Number
- ADA187700
Entities
People
- Chris A. Kapetanakos
- P. Loschialpo
Organizations
- United States Naval Research Laboratory