SPRES study on surface of barium tungsten cathodes coated with os film

Author

Yin Sheng-yi ; Yang Jing-xin ; Zhang Hong-lai ; Wang Yu ; Wang Xin-Xin

Author_Institution

Key Lab. of High Power Microwave Sources & Technol., Chinese Acad. of Sci., Beijing, China

fYear

2010

fDate

14-16 Oct. 2010

Firstpage

19

Lastpage

20

Abstract

In order to study the characteristics of barium tungsten cathodes coated with Os film during activation, a photoelectron spectroscopy using synchrotron radiation (SPRES) at Beijing Synchrotron Radiation Laboratory is utilized. SPRES is a far more sensitive tool to determine surface composition than either XPS or AES. The cathode, manufactured by ourselves, has a stated impregnant composition of 6BaO/CaO/2Al₂O₃, a tungsten matrix porosity of 25-26%, and a sputter-deposited coating of Os approximately 0.35μm thick. The cathode is activated by heating according to A→B→C steps: A-step 950°C × 60 min, B-step 1050°C × 60 min, and C-step 1150°C × 60 min. The vacuum is kept below 1×10^-8 Pa during measurements. The photon energies for SPRES collection are 700 eV and 900 eV, and scan step is 0.16 eV. All photoemission spectra are adjusted by adjusting the Pt4f of the Pt slice welded to the cathode holder surface as 71.20 eV.

Keywords

barium compounds; cathodes; osmium; photoelectron spectra; photoemission; sputtered coatings; surface composition; synchrotron radiation; Ba-W-Os; Beijing Synchrotron Radiation Laboratory; Os film coating; Pt slice; Pt4f slice; SPRES; barium tungsten cathodes; cathode holder surface; photoelectron spectroscopy; photoemission spectra; photon energies; sputter deposition; surface composition; synchrotron radiation; tungsten matrix porosity; Barium;

fLanguage

English

Publisher

ieee

Conference_Titel

Vacuum Electron Sources Conference and Nanocarbon (IVESC), 2010 8th International

Conference_Location

Nanjing

Print_ISBN

978-1-4244-6645-0

Type

conf

DOI

10.1109/IVESC.2010.5644436

Filename

5644436