2 TYPES OF ION GUN EQUIPPED SPUTTER-INITIATED RESONANT IONIZATION ANDTIME-OF-FLIGHT MASS-SPECTROSCOPY AND ITS APPLICATION IN MICROANALYSISOF MINERALS

An apparatus, based on sputter-initiated resonant ionization spectrosc opy and combined with time-of-flight mass spectroscopy, has beer! rece ntly developed for microanalysis of mineral samples and other solid ma terials. This equipment has two kinds of ion gun, which make it possib le to do more convenient and accurate microanalysis of complicated min eral samples. With this apparatus, detection and size measurement of f ine gold grains trapped in pyrite at low concentrations have been carr ied out. The detection limit of this apparatus for gold is 73 ppb. The apparatus also has the function of secondary electron imaging. This g ives very helpful information for geologists to evaluate the inborn st ate of gold in mineral samples and to improve the extraction rate of g old from minerals. (C) 1998 American Institute of Physics.