Kimitaka Sato1, Naoharu Yamaguchi1, Ryo'ichi Suzuki1 and Ryûtarô Matsumoto1
1Tokyo Research Institute, Nippon Steel Corporation, Kawasaki
Mass spectrographic method equipped with a triggered DC spark source is thought to be available for the microprobe analysis of steel, so the correlation of the source condition with the size of the crater and the kind and the shape of the material of the counter electrode were investigated in detail. The experimental results obtained are as follows: The size of the crater for the ion source is remarkablly smaller than that when a radio frequency spark source equipped to a solid mass spectrograph, was used. The sample electrode should be set to a higher voltage side than to an earth side, in order to obtain the smaller size of a crater and to minimize weight of counter electrode by sparking as possible. The size of crater can be made less than 80 microns by controlling the total exposing power to less than 1 × 10-11 coulombs and by sharpening the tip of the material of the counter electrode. Reproducibility is nearly within 10%, so the proposed technique is effective in order to study the behavior of trace elements in a microscopic area of 100 μ diameter on the surface of the steel and the other alloys.
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