X-ray Excitation Source Research Articles

Radioactive implant induced X-ray emission: Part II

The implantation of X-ray excitation sources inside a sample by physical mixing was examined. Radioisotopes used were: 195Au, 75Se, 55Fe, 125I, 35S, 99Tc, and 63Ni. Relative excitation efficiencies of γ and β− emitting radioisotopes, limits of detection for selected elements, and their variation with source strength were studied. For comparable detection limits, the source strengths required are ∼103 less than that needed with external radioisotope sources, ∼106 less than with tube excited sources using wavelength dispersion. The feasibility of implanting an X-ray excitation source into a solid with an accelerated radioactive beam is also discussed.

RADIOACTIVE IMPLANT INDUCED X-RAY EMISSION SPECTROMETRY BY THE USE OF 67Ga, 99mTc, 111In AND 201Tl

Abstract Induced X-ray emission spectrometry was examined by mixing a sample in solution with a radioisotope, which was used as a X-ray excitation source. The radioisotopes used were 67Ga, 99mTc, 111In and 201Tl. The copper, strontium, iodine, barium, lead and uranium solutions were used as the sample to be analyzed. The effective excitation efficiencies for each radioisotope were obtained.

Radioactive implant induced X-ray emission

Two approaches with X-ray excitation sources directly inside a sample have been examined: mixing a sample in solution with a radioisotope or bombardment of a solid specimen with a radioactive ion beam. The radioisotopes used weere 3H, 35S, 125I, with detection limits of, for example, 20 μg/g for Ag excited by a 125I implant of ∼75 kBq; 100 μg/g for Ti excited by a 3H implant of ∼7 MBq. For comparable detection limits, the source strengths required are ∼10 3 less than that needed with external sources. The elemental coverage and the capabilities for simultaneous multielement detection are similar to “conventional” XES. In the beam implant mode, the spot size and energy of the beam provide for spatially resolved in situ X-ray excitation at a desired location inside a solid.