M. Ya. Kuznetsova

The decay of 152Tb

Abstract The conversion electron spectrum, electron-gamma and β + -gamma coincidence spectra are investigated, and the gamma-ray spectrum is studied in two Ge(Li) semiconductor spectrometers. A decay scheme 152 Tb → 152 Gd is suggested, including many new levels among which two 0 + states at 1484.0 and 2720.7 keV. Relative intensities at 0.2 : 0.3 : 1 are found for positon branches from 152 Tb to the 615.6 keV (0 + ), 344.4 keV (2 + ) and to the ground state of 152 Gd. Spin 1 − is ascribed to the ground state of 152 Tb. Spin assignments are being made for the following excited levels: 755.6 keV 4 + , 1109.8 keV 2 + , 1123.8 keV 3 − , 1606.1 keV 2 + , 1643.9 keV 1 − , 1862.3 keV 2 + and 1942.5 keV 2 + .

155Gd levels excited in the decay of155Tb

Conversion electron spectra, gamma rays, and e-γ and γ-γ coincidences in the decay of155Tb were investigated. The conversion electron spectra were measured with a toroidal six-gap beta spectrometer and a two-fold double-focusing π √2 beta spectrometer. The gamma rays were measured by means of Ge(Li) detectors. The e-γ-coincidence spectra were investigated by means of the six-gap beta spectrometer and a NaI(Tl)-gamma spectrometer. The γ-γ-coincidences were studied by the method of two-dimensional analysis with the use of two coaxial Ge(Li) detectors.A number of transitions was found in155Tb decay which were not observed up to now. A more complete scheme of the decay155Tb →155Gd is proposed.Conclusions were reached on the multipolarity of most transitions and possible spin and parity values were determined for the155Gd levels.The populations of the excited levels in155Gd ware determined and the lgft values were calculated.A comparison of the results obtained with the calculations by Solovev et al. based on the superfluid model of the nucleus enables one to assign the structure to the 592·6 keV state as follows: [521]↑−0·7%, [521]↑+Q1(20)−99% and to interpret the 559·9 keV level as a mixed state of the type [521]↺−42%, [521]↑+Q1(22)−37%, [523]↺+Q1(22)−16%.

Low-energy transition depopulating the isomeric 8+ level in 208Po

Abstract Conversion electron measurements of the low-energy transition depopulating the isomeric 8+ level in 208Po yielded Eγ = 4025 ± 20 eV and the conversion intensity ratios N1/N2 ≲ 0.2, N2/N3 = 0.75 ± 0.10, N4.5/N3 ≲ 0.2, O/N3 = 0.35 ± 0.10, P/N3 ≲ 0.1 and N3/M3 = 0.4 ± 0.2. These ratios are in accord with our calculations for the E2 multipolarity and exclude all other multipolarities with L ≦ 4. The total conversion coefficient was calculated to be 1.31 × 107.