Accession Number : ADA132379
Title : Chemical Vapor Deposition of Oriented Tungsten Foils for Thermionic Cathodes.
Descriptive Note : Final rept. 1 Oct 81-30 Nov 82,
Corporate Author : GA TECHNOLOGIES INC SAN DIEGO CA
Personal Author(s) : Yang,L
PDF Url : ADA132379
Report Date : Jun 1983
Pagination or Media Count : 21
Abstract : Efforts under the present contract were devoted to the preparation of CVD tungsten emitters containing a variety of preferred crystallographic orientations. The work is divided into two phases. In Phase I, a CVD tungsten deposition apparatus was built and CVD tungsten samples of various preferred crystallographic orientations were prepared and characterized with respect to microstructures and nature and degree of preferred orientations. These samples were delivered to NRL for the evaluation of their electron emission properties. In Phase II, efforts were made to produce a high degree of preferred crystallographic orientations in thin CVD tungsten deposits (approx. 25 micron thickness) which are amenable to hole drilling by laser. Techniques for preparing CVD tungsten cathode structure were established and samples of oriented tungsten cathode structure were prepared for NRL evaluation.
Descriptors : *Tungsten, *Cathodes, *Vapor deposition, Foils(Materials), Emitters, Crystal structure, Fabrication, Thermionic emission, Orientation(Direction), Physical properties
Subject Categories : Physical Chemistry
Electrical and Electronic Equipment
Distribution Statement : APPROVED FOR PUBLIC RELEASE