PIXE ANALYSIS IN MINERALOGY AND GEOCHEMISTRY

Proton-induced X-ray emission can be used to analyze geological samples for a wide range of trace elements (including transition large-ion-lithophile and high-field-strength elements, and, in favorable circumstances, rare-earth elements) in a variety of minerals down to levels of a few parts per million. The analyses are simultaneous, multi-element, and nondestructive. focused beam of protons (spot sizes typically 5 x 5 mu m) can be used for point analyses, or the beam may be scanned over an area as large as 2 mm x 2 mm to provide a two-dimensional X-ray map of element distribution. The proton beam also may be used for nuclear reaction analysis and proton-induced gamma-ray emission. These techniques may be run concurrently with PIXE and are useful for analyzing a sample for light elements such as Li, B and F, with detection limits in the region of 100 ppm.