Ion microprobe mass spectrometry using sputtering atomization and resonance ionization

Resonance ionization mass spectrometry (RIMS) has been applied to the measurement of U and Sm by utilizing ion beam sputtering atomization. The goal is to produce an ultrasensitive analytical technique for measuring elements of environmental concern in small particles or inclusions. An ion microprobe mass analyzer (IMMA) has been modified to allow production of a sputtered atom plume through which high-powered tunable laser radiation is directed. Ions of a given element are produced by a multistep resonance ionization process followed by extraction into a double-focusing mass spectrometer for detection. Data are presented showing mass and optical spectra obtained as well as the sensitivity of the technique. 22 reference, 9 figures, 1 table.