AUTOMATIC MEASUREMENT OF SECONDARY ELECTRON EMISSION CHARACTERISTICS OF TAC, TIC AND ZRC

A method and apparatus for plotting automatically the secondary electron emission yield curves from metals in an ultra-high vacuum environment are described. The yield curves from metals can be plotted in times of only a few seconds before the surfaces become contaminated. In addition, both the variation of the back-scattering coefficient with primary energy and the yield with angle of incidence of primaries may be plotted. Typical curves from Ni, Pt and Ta are presented to indicate the performance of the apparatus. Measurements using the apparatus are reported on the secondary electron emission characteristics of the three carbides TaC, TiC and ZrC as a function of primary energy and angle of incidence. In addition the yield curves are correlated with a theoretical universal yield curve.