A New Impregnated Dispenser Cathode

Author

Shengyin Yin ; Zhaochuan Zhang ; Zhen Peng ; Qiang Zheng ; Yu Wang

Author_Institution

Key Lab. of High Power Microwave Sources & Technol., Inst. of Electron., Beijing, China

Volume

60

Issue

12

fYear

2013

fDate

Dec. 2013

Firstpage

4258

Lastpage

4262

Abstract

To meet the demand of terahertz devices, we develop a new type impregnated dispenser cathode. This cathode is impregnated with an active substance with molar ratio of 26BaO·29SrO·8Sc₂O₃·7CaO·Al₂O₃. We test its emission performance, practical work function distribution, and surface composition, and analyze the mechanism of the high emission performance. At 1100°CB, the pulse current density is 171.6±2.8 A/cm², 5.4 times of that of an M-type cathode. The peak work function of Miram curve is ~1.570 eV. Ba, Sc, Ca, Al, and O atoms are detected on most surfaces of tungsten grains. It is proposed that the Ba-Sc-Al-Ca-O layer on the surface of the cathode is responsible for the excellent emission performance.

Keywords

aluminium compounds; barium compounds; calcium compounds; cathodes; electron emission; scandium compounds; strontium compounds; BaO-SrO-Sc₂O₃-CaO-Al₂O₃; active substance; emission performance; impregnated dispenser cathode; pulse current; surface composition; temperature 1100 C; terahertz device; Atomic layer deposition; Barium; Cathodes; Current density; Surface treatment; Temperature measurement; Tungsten; Ba; Sr; emission performance; impregnated scandate cathode;

fLanguage

English

Journal_Title

Electron Devices, IEEE Transactions on

Publisher

ieee

ISSN

0018-9383

Type

jour

DOI

10.1109/TED.2013.2287729

Filename

6657795