Effect of the phase composition of barium-calcium alumoscandates on the emission properties of impregnated cathodes

Authors
Get'man, OI Rakitin, SP Panichkina, VV Rud', ZP
Citation
Oi. Get'Man et al., Effect of the phase composition of barium-calcium alumoscandates on the emission properties of impregnated cathodes, POWD MET ME, 39(11-12), 2000, pp. 584-589
Citations number
5
Categorie Soggetti
Metallurgy
Journal title
POWDER METALLURGY AND METAL CERAMICS
ISSN journal
10681302 → ACNP
Volume
39
Issue
11-12
Year of publication
2000
Pages
584 - 589
Database
ISI
SICI code
1068-1302(200011/12)39:11-12<584:EOTPCO>2.0.ZU;2-6
Abstract
The effect of scandium oxide additions on the emission properties of impreg nated tungsten cathodes was investigated. The synthesis of alumoscandates i n the BaO - CaO - Sc2O3 - Al2O3 system were studied by xray diffraction, th ermography, and petrographic analysis. The hygroscopic properties of the em ission-active material was determined. Based on the results of emission res ts the recommended optimal compositions of emission-active material are 2.4 BaO .0.6 CaO . 01 Sc2O3.0.9 Al2O3 and 2.6 BaO .1.9 CaO .0.1 Sc2O3.0.9 Al2O 3. Cathodes based on these compositions had lifetimes greater than 10000 h operating in the temperature range 900-1000 degreesC at current densities o f 15-20 A/cm(2) in a vacuum of the order of 10(-6) Torr.