A new source configuration for trace analysis of small samples by XRF

Abstract

A new geometry for a radioactive source was developed for the XRF determination of trace elements in the range 0.1–50 μg in samples with diameters from 2–5 mm. The new set‐up was constructed with five 241Am (45mCi each) point sources. The shielding and configuration of the source, as well as the choice of appropriate collimators in the optimal shapes and dimensions, were investigated in detail. The study was carried out to establish the conditions for obtaining maximum sensitivity. The count rates and signal‐to‐background ratios were compared with those obtained with an annular source and showed an improvement of a factor of ∼2 in the signal‐to‐background ratio and of a factor of 2–9 in the peak intensity for the elements studied (29≤ Z ≤ 47).

X-ray spectrometry

“…To improve the source configuration for radioisotope XRS determination of trace elements in small samples in the range 0.1-50 fis. Shenberg et al (17) have developed a system based on five ®Am commercially available point sources to obtain a higher signal-to-background ratio and higher peak intensity for elements of 29 < Z < 47 as compared with those obtained from an annular source. Apart from these innovations very little advance has been made in this area.…”