[en] All the known nuclear-structure information on the A = 156 nuclides from ¹⁵⁶Nd through ¹⁵⁶Ta has been reviewed. These data are summarized and presented, together with adopted level schemes and properties based on an evaluation of them.

[en] A double sided silicon strip (DSSD) setup is installed at the Argonne National Laboratory recoil separator FMA. Ground state proton emitters ^146,147Tm, ¹⁶⁰Re, ¹⁵⁶Ta, ^150,151Lu were produced in a series of test experiments. Improved T_1/2 values were obtained for ¹⁴⁷Tm, ¹⁶⁰Re, and ¹⁵⁶Ta. Improved alpha T_1/2 value of (13.2 ± 1.1) ms was obtained for ¹⁶¹Re. In a search of new proton radioactivities a (5 ± 2)% proton decay branch with E_p = (1345 ± 13) keV for ¹⁶¹Re was found

[en] All the known nuclear-structure information on the A=156 nuclides from ¹⁵⁶Nd through ¹⁵⁶Ta has been reviewed. These data are summarized and presented, together with adopted level schemes and properties based on an evaluation of them

[en] We compare α-decay half-life calculations, using parameter values unchanged from previous work, with 88 recent measurements of neutron deficient isotopes in the region N approx-gt 82 approx-gt Z. The results generally reproduce the data to within a factor of 3 or better. Exceptions to this statement occur for decays which do not proceed by s-wave transitions, and also where no α-branching ratio has been measured. In the former cases we calculate the L values for the transitions needed to bring their half-lives into agreement with the experimental values, and for the latter we predict branching ratio values based on the mismatches between the calculated α half-lives and the measured total half-lives. Amongst the 88 reported decays there are no cases which cannot be accommodated satisfactorily within this framework. For completeness we also calculate proton emission half-lives and find excellent agreement with the two observations in ¹⁵⁶Ta reported in the same experimental survey. copyright 1996 The American Physical Society

[en] A new proton emission line has been observed in the nucleus ¹⁵⁶Ta using the fusion reaction ⁵⁸Ni+¹⁰²Pd→¹⁶⁰W^*, E_x congruent 61 MeV. The line has a proton energy E_p=1103±12 keV corresponding to a Q value Q_p=1110±12 keV, and a half-life of 320±80 ms. The proton line is assigned to a ∼3% decay branch from a high spin πh_11/2νf_7/2 isomeric state on the basis of systematics. The subsequent implications for level ordering in this region beyond the proton drip line are discussed

[en] The heaviest known examples of proton radioactivity, ¹⁶⁰Re and ¹⁵⁶Ta, have been discvovered. Evaporation residues from fusion reactions of 300 MeV ⁵⁸Ni ions with ¹⁰⁶Cd targets have been mass separated in flight and implanted into a double-sided silicon strip detector. The measured proton energies, total half-lives, and proton branching ratios are 1261±6 keV, 790±160 μs, 91±10%, and 1022±13 keV, 165_-55⁺¹⁶⁵ ms, ∼100% for ¹⁶⁰Re and ¹⁵⁶Ta, respectively, indicating that the protons are emitted from a d_3/2 orbital in each case. An energy of 6537±16 keV has been measured for the ¹⁶⁰Re alpha decay branch

[en] The decays of the πd_3/2 ground states of ¹⁵⁶Ta and ¹⁶⁰Re have been studied in detail using the GREAT spectrometer. More than 7000 ¹⁶⁰Re nuclei were produced in reactions of 290- and 300-MeV ⁵⁸Ni ions with an isotopically enriched ¹⁰⁶Cd target and separated in flight using the RITU separator. The proton and α decays of the πd_3/2 level were confirmed and the half-life and branching ratios of this state were determined with improved precision to be t_1/2=611±7 μs and b_p=89±1% and b_α=11±1%, respectively. The α-decay branch populated the ground state of ¹⁵⁶Ta, allowing improved values for the proton-decay energy and half-life to be obtained (E_p=1011±5 keV; t_1/2=106±4 ms). The β decay of this level was identified for the first time and a branching ratio of b_β=29±3% was deduced. The spectroscopic factors deduced from these measurements are compared with predictions.

[en] The potential barrier impeding the spontaneous emission of protons in the proton radioactive nuclei is calculated as the sum of nuclear, Coulomb and centrifugal contributions. The nuclear part of the proton-nucleus interaction potential is obtained in the energy density formalism using the Skyrme effective interaction that results into a simple algebraic expression. The half-lives of the proton emitters are calculated for the different Skyrme sets within the improved WKB framework. The results are found to be in reasonable agreement with the earlier results obtained for more complicated calculations involving finite-range interactions. (orig.)

[en] The stability line for neutron deficient nuclei will be determined by radioactive emission of protons. The presently known cases are reviewed, and experimental techniques for production and investigation of proton emitters are described. The emission probabilities are discussed within a semiclassical model. (orig.)

[en] The stability line for neutron deficient nuclei will be determined by radioactive emission of protons. The presently known cases are reviewed, and experimental techniques for production and investigation of proton emitters are described. The emission probabilities are discussed within a semiclassical model. (author)