[en] Sorption of fission products of radionuclides ¹³⁷Cs, ^89,90Sr, ^90,91Y, ⁸⁶Rb, ¹³³Ba, ⁹⁵Zr+⁹⁵Nb, ⁹⁵Nb, ^103,106Ru, ^141,144Ce, ^115mCd, ¹¹³Sn, ¹²⁵Sb by hydroxides Fe(III), Mn(IV) on the background of 1 mol/l of NaNO₃ at the pretense of ions SO₄^2-, C₂O₄^2- at a wide ph range (1+14) is studied in present work. Optimal conditions of extraction of each radionuclide by sorption on inorganic sorbents are defined.

[en] The independent isomer yield ratio for ⁹⁰Rb from thermal neutron fission of ²³⁵U has been measured by use of a new technique involving a pulsed reactor and an on-line mass spectrometer facility. The apparent isomer yield ratio was measured for different ion collection time intervals and extrapolated to zero collection time to eliminate interference from ⁹⁰Kr decay. The observed isomer yield ratio of 8.7 +- 1.0 is one of the largest ratios measured for a low energy fission process. However, a statistical model analysis shows that the average angular momentum (< J> = 4.5) deduced from this isomer yield ratio is consistent with average angular momentum for other products from low energy fission. 7 refs

[en] The 1961 version of Nuclear Data Sheets for A = 90 and the 1970 Midstream Evaluation, A = 90 were revised on the basis of experimental data received prior to May 1, 1975. Results from approximately 225 papers and communications chosen from the extensive literature for this A--chain were included in the present evaluation. Numerous additional references dealing with reaction mechanism studies and nuclear structure theory are not included in this compilation, but are available upon request from the Nuclear Data Project. Data on nine A = 90 nuclei are presented. The decay of ⁹⁰Br has been observed, but the decay scheme has not been established. Recent unpublished results on ⁹⁰Kr and ⁹⁰Rb decays are presented. These results are not yet complete, but appear to be considerably more extensive than previously published work. The particularly simple decay schemes for ⁹⁰Sr and ⁹⁰Y are well known. A few spin assignments have been proposed for levels in ⁹⁰Sr, but additional reaction studies would be useful. Many spin assignments have been made for levels in ⁹⁰Y, ⁹⁰Zr, ⁹⁰Nb, and ⁹⁰Mo from a variety of decay and reaction studies. The results for ⁹⁰Zr are particularly extensive. The decay schemes for ⁹⁰Nb and ⁹⁰Mo appear reasonably well established. Recent results on the decay of two ⁹⁰Tc isomers are presented, but the decay schemes have not been established and the energy ordering of the two isomers is not known. (authors)

No abstract available

[en] Angular correlation measurements were made on gamma-ray cascades in ¹⁴⁰Ba, ⁹⁰Sr, and ¹⁴⁰Cs. These fission-product activities were isobarically enhanced from Kr and Xe noble-gas parents, which were mass-separated by the TRISTAN isotope separator system. Levels in ¹⁴⁰Ba were populated from the 64-sec decay of ¹⁴⁰Cs, and in ¹⁴⁰Cs from the 14-sec decay of ¹⁴⁰Xe. Levels in ⁹⁰Sr were populated from the 2.7-min decay of ⁹⁰Rb, which was populated from the decay of ⁹⁰Kr. The most intense transitions were measured in coincidence with the first excited state to ground state transition in even-even ¹⁴⁰Ba and ⁹⁰Sr. The two-parameter mode of data accumulation was used to study cascades with transitions in coincidence with the 806-keV and 989-keV transitions in odd-odd ¹⁴⁰Cs. In the study of cascades in ¹⁴⁰Ba definite spin assignments were made for eight levels, and tentative spin assignments for five levels. For ⁹⁰Sr definite spin assignments were made for eight levels, and tentative assignments for six levels. A definite 1- spin-parity assignment was made for the 103-keV level in ¹⁴⁰Cs, and tentative assignments were made for five other levels. Values are given for the angular correlation coefficients, and limits of multipolarity mixing ratios are given where applicable. (44 figures, 3 tables) (U.S.)

[en] The independent isomer yield ratio for ⁹⁰Rb from thermal neutron fission of ²³⁵U has been measured by use of a new technique involving a pulsed reactor and an on-line mass spectrometer facility. The observed isomer yield ratio of 8.7 +- 1.0 is one of the largest ratios measured for a low energy fission process. However, a statistical model analysis shows that the average angular momentum (< J> = 4.5) deduced from this isomer yield ratio is consistent with average angular momentum for other products from low energy fission. (author)

[en] Independent isomeric yield ratios of ⁹⁰Rb(1-,4-) and ¹³⁸Cs(3-,6-) in the spontaneous fission of ²⁵²Cf were measured by the radiochemical method. A gas-recoil-transport-system was used for the fast and continuous separation of Rb and Cs from their noble gas precursors Kr and Xe, respectively, in the decay chain. The mean angular momentum of the primary fragments was deduced from the isomeric yield ratios. The results are compared with the results of a previous study. The results indicate that the mean angular momentum of fission fragments is nearly independent of fragment mass. (author)

[en] The TRISTAN on-line mass separator facility at Brookhaven National Laboratory is being used to measure half-lives and delayed neutron emission probabilities (P/sub n/) of fission-product delayed-neutron precursors. Because delayed neutron emission can be detected with high sensitivity in the presence of large intensities of beta and gamma radiations, we also use neutron counting to search for new isotopes among the very neutron-rich fission products. 6 refs., 1 tab

[en] A systematic study of nuclear moments and rms charge radii in Rb was made possible by extending high-resolution cw laser spectroscopy into the deep blue. Measurements of optical isotope shifts and hyperfine structure of fission-produced ^89-93Rb are reported. (Auth.)

[en] The ground-state β branchings for several mass-separated Kr fission products and their daughters have been measured at the TRISTAN on-line separator facility at the Ames Laboratory Research Reactor. Absolute β counting was done with a 4π-geometry plastic scintillation detector and γ spectra were taken simultaneously with a Ge(Li) detector. The deduced values of the ground-state β branching β/sub gs/, expressed as a percentage of decays, are: ⁸⁸Kr, 14 +- 4; ⁸⁸Rb, 78.0 +- 1.2; ⁸⁹Kr, 23 +- 4; ⁸⁹Rb, 25 +- 5; ⁹⁰Kr, 29 +- 4; ⁹⁰Rb/subg/, 37 +- 5; ⁹¹Kr, 10 +- 4; ⁹¹Rb, 5 +- 5