No abstract available

[en] The results of search of the ⁹⁶Zr neutrinoless double β-decay are described. The ⁹⁶Mo experimental plant is described earlier. The experiment techniqUe is based on measurement of scintillation detector back-ground made of 14 separate plates-scintillators on a polystyrene base in which a defenite nuclei number of the ⁹⁶Zr under study is introduced. The ⁹⁶Zr, ⁹⁶Nb and ⁹⁶Mo levels scheme, background spectra obtained in the course of the experiment are presented. No peculiarities which can be related to possible neutrinoless decay are present in the spectra. Therefore on the basis of experimental data it is possible to estimate only the lower limit of the ⁹⁶Zr half-life period. It has been found that the lower limit of the half-life period with the 68% confidence level probability equals 3x10¹-- ⁹ years. The previously obtained limiting value of the ⁹⁶Zr half-life period equals Tsub(1/2)>=5x10¹⁷ years. It is noted that the obtained in the course of the experiment results do not exceed yet maximum theoretical estimation because of the lack of precise theoretical calculations of the ⁹⁶Zr neutrinoless 2β decay (the data available assume the interval of 10¹³-10²¹ years)

[en] A short survey is given about the work performed by the Nuclear Spectroscopy Research Group of the Institute in the last few years. The nuclei under investigation (^9798100Tc and ⁹⁴⁹⁶Nb) were produced via (p,n) reactions from enriched targets. The γ-, γγ-coincidence, and conversion electron spectra of the reactions were taken with Ge(Li), thin-window hyperpure Ge, and super-conducting magnet transporter Si(Li) spectrometers. The energies and the intensities of the observed radiations as well as the excitation functions of the reactions were measured. Level schemes; multipolarities of transitions; and energies, spins, and parities of nuclear levels have been deduced. The level schemes have been compared with the results of recent shell model calculations. 5 figures, 1 table

[en] The structures of sup(114)In, sup(102)Rh, sup(100)Tc, sup(98)Tc, sup(96)Nb, sup(94)Nb, sup(82)Br, sup(76)As, and sup(70)Ga odd-odd nuclei were investigated with in-beam spectroscopic methods. The nuclei were produced from enriched isotopes through the (p,nγ) reaction. Using different spectrometers and semiconductor detectors, data were obtained on the energies and intensities of hard and soft γ-rays, conversion electrons, on γ-threshold energies, reaction cross sections, multipolarities of transitions, different coincidence relations, energies, spins and parities of excited states. The energy levels of the nuclei were calculated on the basis of parabolic rule derived from the cluster-vibration model. Many proton-neutron, proton-phonon-neutron quasiparticle (and cluster) multiplet states were identified. Conclusions are drawn on the applicability of the parabolic rule for the theoretical description of multiplet states. (author)

No abstract available

[en] Fast neutron inelastic scattering cross sections have been measured for the elements Al, Ti, V, Mn, Fe, Ni, Nb, Pb and Bi by the time-of-flight technique. The measurements were made in the energy range of 2 to 4.5 MeV in steps of 0.25 MeV and at a scattering angle of 125⁰. The experimental results are compared to the excitation functions calculated on the basis of the Hauser-Feshbach formalism and corrected for the effects of the level width fluctuations. 9 figures

[en] A reverse-phase chromatographic isolation procedure for Nb from Mo and Tc is given. The separation is performed with TBP (tri-n-butyl phosphate) on celite column. Molybdenum oxide was irradiated with 20MeV bremsstrahlung, which produces a mixture of ^93mMo, ⁹⁹Mo; ^99mTc; ^91mNb, ^95mNb, ⁹⁵Nb and ⁹⁶Nb. The irradiation was applied to a 6 N HCl solution of the target. Separation was repeated twice, which resulted in isolation of the radioniobium with a decontamination factor of 10⁴ both for Mo and for Tc. Decay analysis of the activity showed that radioniobium thus separated was composed of ^91mNb, ^95mNb, ⁹⁵Nb and ⁹⁶Nb. The γ-spectrum of ⁹⁶Nb was obtained by subtraction of the spectrum taken 119 hr after the end of irradiation from that of 74 hr. (author)

No abstract available

No abstract available

[en] The independent yields of ⁹⁶Nb and 51 min ⁹⁸Nb were determined in the thermal neutron-induced fission of ²³³U, ²³⁵U and ²³⁹Pu using radiochemical techniques. The results for these fissionable nuclides are as follows for ⁹⁶Nb: (5.3 + - 0.3) x 10^-3%, (5.2 + - 0.2) x 10^-4% and (3.6 + - 0.1) x 10^-3%, respectively, and for 51 min ⁹⁸Nb: (0.13 + - 0.03)%, (0.034 + - 0.015)% and (0.16 + - 0.03)%, respectively. (author)