ABSTRACT
Sputtering produces diverse ion species (ions with either polarity, monatomic ions of various charge states, multi-atomic ions such as dimers, trimers and more complex molecules). Sputtered ion formation is also a selective process, and a population of secondary ions is chemically and isotopically fractionated relative to the true composition of sample. It was essentially because of this complexity of SIMS spectra that it took more than a decade of effort before ion microprobe analysis proved useful in geochemistry. Technical difficulties caused by the complexity of SIMS spectra have, however, motivated and led instrumentalists to improved machine design and performance. The part played by the earth and planetary sciences community in recent technical development has been essential.
