TY - JOUR
T1 - Quantitative LEIS analysis of thermionic dispenser cathodes
AU - Cortenraad, H.M.R.
AU - Denier van der Gon, A.W.
AU - Brongersma, H.H.
AU - Gärtner, G.
AU - Manenschijn, A.
PY - 1999
Y1 - 1999
N2 - 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 M-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.
AB - 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 M-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.
U2 - 10.1016/S0169-4332(99)00013-6
DO - 10.1016/S0169-4332(99)00013-6
M3 - Article
SN - 0169-4332
VL - 146
SP - 69
EP - 74
JO - Applied Surface Science
JF - Applied Surface Science
IS - 1-4
ER -