Analysis of Medium and Heavy Elements by Means of K X-Ray Fluorescence Induced by 20-50 MeV Protons

The technique of K x-ray fluorescence induced by 20-50 MeV protons appears to be well suited for use in trace element analysis of medium and heavy elements as the K x-ray yield is high at these proton energies. The separation in energy between K x-rays from adjacent heavy elements in the periodic table is such that spectra taken with a suitable Ge(Li) detector are readily analysed, and individual elements identified. Because of the high energy of the K x-rays, self absorption in the sample is greatly reduced over L x-rays from the same element - in some cases by several orders of magnitude. With thin samples, the effects of self-absorption are usually negligible, and beam energy loss in the sample is small. Some problems of targetry are discussed.