Quantitative LEIS analysis of thermionic dispenser cathodes

被引：24

作者：

Cortenraad, R

van der Gon, AWD

Brongersma, HH

Gärtner, G

Manenschijn, A

机构：

[1] Eindhoven Univ Technol, Fac Appl Phys, NL-5600 MB Eindhoven, Netherlands

[2] Philips Forschungslab, D-52085 Aachen, Germany

[3] Philips Components, NL-5600 MD Eindhoven, Netherlands

来源：

APPLIED SURFACE SCIENCE | 1999年 / 146卷 / 1-4期

关键词：

cathodes; thermionic emission; LEIS; surface quantification; neutralisation; ion fraction;

D O I：

10.1016/S0169-4332(99)00013-6

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

An UHV LEIS setup has been converted into a dedicated apparatus to study the surface composition, structure and dynamics of real dispenser cathodes and cathode model systems based on W single crystals. LEIS, AES and LEED are available to investigate the surface characteristics, and the cathode emission properties are derived in situ from a close-spaced diode configuration. In this paper, the focus is on the quantitative surface composition of B-type and hi-type dispenser cathodes by LEIS. A straightforward quantification is hampered by the influence of the cathode workfunction on the neutralisation of the ions. It is shown that the ion fraction decreases as the workfunction of the cathode decreases. The Ba surface density is observed to increase with decreasing workfunction, However, before an accurate quantitative surface analysis can be performed a validation of the model used to correct for the influence of the ion fraction has to be performed. (C) 1999 Elsevier Science B.V. All rights reserved.

引用

页码：69 / 74

页数：6

共 10 条

[1]

CORTENRAAD R, P ITG 98 C DISPL VAC

[2] AUGER CHARACTERIZATION OF NEW AND AGED DISPENSER CATHODE SURFACES [J].