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Two methods of Lu-177 production are reviewed: irradiation of isotopically enriched Lu- 176 (direct way) and irradiation of ytterbium enriched with Yb-176 (indirect way). Based on neutronphysical calculations Lu-177 yield and specific activity were estimated for both methods. Lu-177 specific activity strongly depends on neutron flux density in the direct way, that is 75,000 Ci/g for 10- days irradiation in a neutron flux of 2.10(15) cm(-2) s(-1), and only 13,000 Ci/g after 30 days irradiation at neutron flux 1.10(14) cm(-2) s(-1). Irradiation of Yb-176 provides Lu-177 specific activity close to theoretical value (110,000 Ci/g). Neutron flux density effect Lu-177 yield, that is 530 Ci/g for 2.1015 cm(-2) s(-1) neutron flux density after 30 days irradiation. A procedure of isolation and purification of Lu-177 from irradiated targets is described based on combination of galvanostatic extraction of ytterbium followed by cation-exchange chromatography from alfa-hydroxyisobutirate solutions on BioRad AG(®)50W-X8 resin.

Experiments to study non-standard properties of neutrinos using high-intensity artificial neutrino sources require high accuracy in determining their activity. A calorimetric system to determine the activity of a ^51Cr neutrino source in the experiment BEST with an accuracy better than 1% was created. The design of the calorimetric system and the main factors affecting the accuracy of measurements are considered. The results of measurements of the activity of the source made for the BEST experiment are presented. The value of the source activity from calorimetric measurements was 3.41 MCi at the beginning of the experiment.

The recent Russian results on technetium transmutation into ruthenium are summarized, including the first isolation of artificial stable ruthenium from irradiated technetium targets. To cite this article: V.

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