Determination of microquantities of Be in samples using α-sensitive track etch detectors

Abstract

A new technique of determining Be content in samples using 4.6∸6 MeV γ-rays is proposed. This energy range is sufficient to knock out the neutron from the 9Be nucleaus and to excite the first 2.9 MeV level of the 8Be nuclei. 1.5 MeV alpha particles are registered by means of CR-39 or cellulose nitrate detectors. Alpha particles produced in the reaction of γ-rays with Li nuclei which are contained in samples may cause the background. The latter is excluded by heating of samples before irradiation for Li molecules to be evaporated. 11B nuclei do not produce alpha particles at the energy range of γ-rays presented above. The results obtained in the experiments of determining Be content in natural beryl crystal samples are in good agreement with their known chemical composition. Microparticles containing Beryllium were found in soil samples from the Ust-Kamenogorsk are deposit region, which contains 10 −3 − 10 −4 g/g of Be. The sensitivity of the method is 10 −6 g/g of Be in solids.