²⁴¹Am Radioisotope-Excited Spectrometer for K-Line X-ray Fluorescence (XRF) Analysis of Rare Earth Elements

We describe a radioisotope-excited energy dispersive X-ray fluorescence spectrometric facility for the elemental analysis of minerals containing the rare earth elements (REEs) by the use of the K-line X-rays. Two ²⁴¹Am sources are used in purpose-designed holders that fit a high-resolution solid-state germanium detector. The system is capable of exciting all the light actinides up to element 69, Tm. The analysis through the well-separated K-lines allows an easy identification of lanthanide elements with advantages over traditional L-line detection particularly in mineral samples with high Fe concentration, enabling the recognition of most lanthanide elements at values close to 10 ppm. We report the achieved elemental sensitivity obtained with a set of pure element standards and spectra of mineral concentrates derived from a REEcontaining Venezuelan Laterite.