Recovery of 1 2 5Sb from Neutron-Irradiated 1 2 4Sn

Recovery of ^{1 2 5}Sb from metallic tin (96% enrichment with ^{1 2 4}Sn) irradiated in a nuclear reactor (specific activity 5 mCi g^{- 1}) was studied. Irradiated tin was dissolved in concentrated HCl with addition of H₂O₂ or Br₂; dissolution was monitored with ^{1 1 9 m} Sn tracer. The separation of ^{1 2 5}Sb and tin was studied using strongly basic (Dowex-50, AV-17), moderately basic (AN-2FN), and weakly basic (AN-31) anion exchangers with HCl, HCl + HBr, and HNO₃ eluents. In the case of strongly basic anion exchangers, the separation coefficients of ^{1 2 5}Sb from tin reached 10⁴-10⁵ in a single cycle. From for AN-31 weakly basic anion exchanger, tin was almost completely removed with 0.8 M HCl; the yields of tin and ^{1 2 5}Sb were 99 and 98%, and the content of ^{1 2 5}Sb in tin was no more than 0.1% of the initial activity.     

The solubility product of the hydroxide of tetravalent uranium

This article gives a calculation of the solubility product of the hydroxide of tetravalent uranium, a knowledge of which is essential for the efficient operation of many processes in the treatment of uranium and methods for determining it. The calculation is based on experimental data obtained in the potentiometric titration of a chloride solution of tetravalent uranium by alkali. The activity of the hydrogen ions was determined by a tube potentiometer LP-5; the active concentration of the quadruple charged ion of tetravalent uranium was calculated from the analytically found concentration of tetravalent uranium with an allowance for hydrolysis and the value of the ionic strength. It is shown that the required solubility product is equal to (1.10±0.72)·10^–52.     

On the transformation of ß-particle energies to electric energy in germanium crystals with p-n junctions

We present the results of an investigation performed in 1955 on the transformation of the energy of fast electrons into electric energy by germanium crystals with p-n junctions, as well as data on the efficiency of this transformation and its dependonce on the absorbed radiation flux and total dose. It is found that the basic factor reducing the efficiency of transformation is the increase of the recombination rate of electrons and holes on recombination levels of structural defects arising as a result of the irradiation. Changes in the equilibrium electric conductivity and carrier mobilities play a secondary role. A method is indicated for reestablishing the initial properties of crystals by heating them. Ionization curves are given for monoencrgetic electron beams in germanium.The authors express their sincere gratitude to P.Ia. Glazunov who took part in the experiments with the artificially accelerated electrons, and to P.N. Kodochigov for his valuable help in the preparation and examination of the Sr⁹⁰–Y⁹⁰ samples.