Rapid turn-on of shelf-stored tubes: an update

Author

Haas, G.A. ; Thomas, R.E. ; Marrian, Christie R.K. ; Shih, Arnold

Author_Institution

B.K. Systems, Washington, DC, USA

Volume

38

Issue

10

fYear

1991

fDate

10/1/1991 12:00:00 AM

Firstpage

2244

Lastpage

2251

Abstract

The authors discuss the poisoning during shelf storage, of cathode surfaces as a result of adsorption of ambient gas residuals. The magnitude of the poisoning depends on the type of cathode and residual gas and follows the same order in which these different cathodes adsorbed the various ambient gases (i.e. sticking coefficients). Turn-on consists of several simultaneous processes. These involve the desorption of the poisoning compounds and the regeneration of a new Ba-O surface via the impregnant within the cathode matrix. The effects which various factors have on the reactivation time are also discussed. These include different exposures to poisoning gases, heating time and temperature, Ba impregnant concentration, Ba-O bonding, cathode types, surface composition and pore spacing. In addition, from analysis of low-energy interatomic and valence Auger data, the surface configurations were determined during various stages of poisoning and activation

Keywords

adsorption; desorption; microwave tubes; thermionic cathodes; Ba impregnant concentration; Ba-O bonding; BaO; adsorption; ambient gas residuals; cathode matrix; cathode surfaces; cathode types; desorption; heating time; impregnant; poisoning gases; pore spacing; rapid-turn-on; reactivation time; shelf-stored tubes; sticking coefficients; surface composition; temperature; valence Auger data; Bonding; Cathodes; Electrons; Gases; Heating; Modems; Surface finishing; Surface topography; Temperature; Toxicology;

fLanguage

English

Journal_Title

Electron Devices, IEEE Transactions on

Publisher

ieee

ISSN

0018-9383

Type

jour

DOI

10.1109/16.88506

Filename

88506