Electron Probe X-Ray Microanalyzer

A 1–3 micron electron probe of simplified design has been constructed for x-ray spectrochemical analysis of metallic and nonmetallic specimens. At operating conditions of 20–30 kv and less than 0.1 microampere beam current, counting rates of about 3000 counts per second are obtained from pure elements such as iron; thus compositions as low as a few tenths percent are detectable. At increased voltage and current and with a beam size of 10–20 micron, counting rates may be increased to 50 000 counts per second. Applications include analysis of inclusions in metals and minerals, mass transfer material from liquid-metal cooling systems, phase composition, and intermetallic diffusion studies.