An ultra-high vacuum time-of-flight (TOF) atom-probe field-ion microscope (FIM) specifically designed for the study of defects in metals is described. Performance experiments show that this instrument can clearly resolve the seven stable isotopes of molybdenum, the five stable isotopes of tungsten, and the two stable isotopes of rhenium in a tungsten-25at.% rhenium alloy. The entire process of applying the evaporation pulse to the FIM specimen, measuring the dc and the pulse voltages, and analyzing the TOF data is controlled by a Nova 1220 computer. With this automated system we can presently record and analyze 600 TOF events min-1.
|Original language||English (US)|
|Number of pages||4|
|State||Published - May 1976|
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