DETERMINATION OF MICROQUANTITIES OF BE IN SAMPLES USING ALPHA-SENSITIVE TRACK ETCH DETECTORS

A new technique of determining Be content in samples using 4.6 divided by 6 MeV gamma-rays is proposed. This energy range is sufficient to k nock out the neutron from the Be-9 nucleus and to excite the first 2.9 MeV level of the Be-8 nuclei. 1.5 MeV alpha particles are registered by means of CR-3S, or cellulose nitrate detectors. Alpha particles pro duced in the reaction of gamma-rays with Li nuclei which are contained in samples may cause the background. The latter is excluded by heatin g of samples before irradiation for Li molecules to be evaporated. B-1 1 nuclei do not produce alpha particles at the energy range of gamma-r ays presented above. The results obtained in the experiments of determ ining Be content in natural beryl crystal samples are in good agreemen t with their known chemical composition. Microparticles containing Ber yllium 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.