MEASUREMENT OF TOTAL AND PHOTOELECTRIC CROSS SECTIONS OF RARE EARTH ELEMENTS PRESENT IN COMPOUNDS FOR 123.6 keV AND 145.4 keV PHOTONS

摘要

A new, simple and direct method proposed earlier by us has been employed here to measure the total photoelectric cross sections of rare earth elements in the range 58 ≤ Z ≤ 66 present in compounds at 123.6 keV and 145.4 keV photon energies. The K X-ray fluorescence intensities emitted by these elements, from irradiating their compounds by the photons of above energies, are measured using a NaI (Tl) spectrometer system in a 2π geometrical configuration. The K X-ray fluorescence cross sections of the rare earth elements are determined, from which the total photoelectric cross sections are evaluated. Total mass attenuation coefficients of compounds for the K X-ray and the incident radiations respectively have been measured and these values were compared with the corresponding theoretical values and a good agreement between them is obtained.