DC Emission Characteristic of Nanosized-Scandia-Doped Impregnated Dispenser Cathodes

Author

Wenlong Liang ; Yiman Wang ; Jinshu Wang ; Wei Liu ; Fan Yang

Author_Institution

Sch. of Mater. Sci. & Eng., Beijing Univ. of Technol., Beijing, China

Volume

61

Issue

6

fYear

2014

fDate

Jun-14

Firstpage

1749

Lastpage

1753

Abstract

To meet the requirements for advanced vacuum electron devices and modern electron beam instruments, dc emission properties of nanosized-scandia-doped impregnated (SDI) cathodes have been investigated in a closely spaced diode configuration system with water-cooled copper anode. The SDI cathodes were made from nanosized-scandia-doped tungsten powder, which was produced by a spray-drying process. A space-charge-limited dc current density of over 60 A/cm² has been measured at 950 °C_b. An on-going life test with a dc load of 30 A/cm² at 950 °C_b has completed more than 2000 h of operation to date. The electron cooling for dc beam emission is discussed.

Keywords

cathodes; current density; drying; electron field emission; life testing; powder technology; scandium; space charge; spraying; tungsten; DC beam emission characteristic; SDI cathodes; W:Sc; advanced vacuum electron devices; closely spaced diode configuration system; electron beam instruments; electron cooling; nanosized-scandia-doped impregnated dispenser cathodes; nanosized-scandia-doped tungsten powder; on-going life test; space-charge-limited dc current density; spray-drying process; temperature 950 degC; water-cooled copper anode; Cathodes; Current density; Density measurement; Powders; Temperature measurement; Tungsten; Scandate cathode; thermionic emission; vacuum electron devices (VEDs); vacuum electron devices (VEDs).;

fLanguage

English

Journal_Title

Electron Devices, IEEE Transactions on

Publisher

ieee

ISSN

0018-9383

Type

jour

DOI

10.1109/TED.2014.2319298

Filename

6810805