QUANTITATIVE DEPTH PROFILING ANALYSES OF THE SURFACE-LAYER IN BE-CU DYNODES

A programmable SIMS instrument was developed and used to perform accurate depth profiling analyses of an activated Be-Cu alloy. The instrument provides information at every 75 A under typical ion bombarding conditions, 0. 3 mu A of 8 keV **4**0Ar** plus . Analytical results indicate that the BeO of 10 wt. % or more is formed on the surface, which is composed of a reasonably homogeneous BeO layer with a thickness of the order of 300 to 500 A. The BeO spreads out toward the inner layer and reaches 5000 A or more. The Be concentration on the surface is less than 0. 2 wt. %, but at a depth of more than 3000 A it approximates the concentration of the mother body, about 1. 9 wt. %.