D.J. Horen

Nuclear data sheets for A = 92

Abstract The 1960 version of the Nuclear Data Sheets for A = 92 has been revised on the basis of experimental data received prior to March 1, 1972. Information from approximately 150 papers and communications has been included in the present evaluation. Ten nuclei are known for A = 92. Only the presumed ground states and their half-lives have been established for 92Br, 92Kr, and 92Ru. Extensive investigations of the 92Kr, 92Rb, and 92Sr decay schemes have been reported, but few spin-parity assignments can be made for levels in the daughter nuclei. The stable nuclei 92Zr and 92Mo have been studied via β-decay, γ-decay, transfer reactions, and inelastic scattering; an appreciable number of spin assignments for low-lying levels are firm. Levels in 92Nb up to 0.5 MeV in excitation are well established by transfer reaction and γ-decay studies; however, only tentative spin assignments can be made, many of which are based on shell-model arguments. An analysis of a preliminary 92Tc decay scheme has resulted in a tentative Jπ=(7+) assignment for the 92Tc ground state, a value not previously suggested in the literature. Reaction, γ-decay, and 92Ru decay studies have established some excited levels in 92Tc, but no spins are known. Several important gaps and uncertainties remain in the data. The normalizations for transition intensities in the 92Kr and 92Rb decay schemes determined by an indirect method result in unexpectedly low log ft values for the ground-state β-branches. Reaction studies are needed to resolve the ambiguity in the placement of low-lying levels in 92Y from 92Sr decay. Above 2.4 MeV in excitation in 92Zr, the correspondence between levels observed in 92Y decay, transfer reactions, and inelastic scattering is not well determined, resulting primarily from the lack of precise energy determinations in reaction studies. An accurate determination of the half-life of the 92Nb ground state and a careful search for the γ-decay of the first-excited state might establish the spin of the ground state independently of shell-model arguments. Firm spin assignments for the lowest-lying 6+ and 8+ levels in 92Mo and a confirmation of the proposed 92Tc decay scheme are required for a firm spin assignment for the 92Tc ground state. The placement of levels in 92Tc observed in γ- and β-decay is uncertain.

Nuclear data sheets for A = 95

Abstract The 1960 version of the Nuclear Data Sheets for A = 95 has been revised on the basis of experimental data received prior to May 1972. Information from approximately 175 papers and communications has been included in the present compilation. The data have been examined and utilized to construct level and decay schemes. Inconsistencies in the data are indicated either by direct comparison or in footnotes. Reported normalizations for the decay of 95Y differ considerably. For the stable nucleus 95Mo, approximately 60 levels are known; however, firm spin assignments can be made for only a few of these, mainly below 1.5 MeV. A similar situation exists in other nuclei in this mass chain. The present compilation might serve as a basis for choosing definitive experiments which would augment our knowledge in this mass chain.

Nuclear data sheets for A = 85

Abstract Available experimental nuclear data have been examined and utilized to prepare level schemes and decay properties for the mass number A=85 chain. Inconsistencies found in the data are noted. The compilation has revealed a lack of information for most of the nuclei in this A-chain and, hence, few firm spin and party assignments could be made. Data received prior to September 1970 have been included. One paper received after that time has been added in proof.

Nuclear Data Sheets for A = 228

Abstract The experimental data for nuclei in the mass chain A = 228 have been examined, and the results summarized. Where possible, the results are presented in pictorial form. The text contains tables of adopted levels and properties, tables of radiations, comments which point out deficiencies or inconsistencies in the data, and a reference list. For those cases where only tentative or partial decay schemes are given, the reader is encouraged to contact the compiler for more specific detail. Structure information is relatively sparse except for the 228Th nucleus. Except where noted, Q—values have been adopted from 74WaBG. Data for the decay of the ground states of the A = 232 isotopes have been taken from 70Sc37 since there has been little modification except for the half—life of 232Pu (see 73Ja06) and alpha decay of 232U (see 71So15 and 72Go33). Data on the alpha decay of A = 228 nuclei have been taken from the compilation for A = 224 (this issue) by Y. A. Ellis. In the drawings, transition intensities per 100 decays of the parent are given. The compilation has been prepared by computer from data sets entered by the compilers into the Evaluated Nuclear Structure Data File (ENSDF). Corrections or additions to the content of this compilation should be addressed to the compiler for inclusion in the ENSDF.

Nuclear data sheets for A = 171

Abstract The experimental data for nuclei in the mass chain A = 171 have been examined, and the results summarized. The compilers have deviated somewhat from standard Nuclear Data Sheet practices. They have done so 1) by excluding some symbols normally included in drawings (e.g., coincidence dots) 2) by minimizing the effort devoted to the data per se , and concentrating on only that data needed to summarize the present status of the physics involved. Of the ten nuclei identified thus far in this mass chain, the data yield considerable information pertaining to the low—lying structure of 171 Yb and 171 Lu. For these nuclei, many of the expected Nilsson states (and rotational bands) have been established. The probable decay of 171 Ta (supposedly 7/2 + [404]) to members of the 1/2 − [521] band in 171 Hf is somewhat puzzling. It is hoped that the present compilation might serve as a basis for choosing definitive experiments that would augment our knowledge of nuclei in this mass chain.

Nuclear data sheets for A = 129*

Abstract The literature pertaining to nuclei in the A = 129 mass chain has been examined and the experimental data summarized in the present compilation. A minimum of numerical data is included. Few definitive spin and parity assignments could be made. Decay data for 129Ba indicate the existence of two isomers with nearly equal half-lives. Using unpublished results, the compilers propose these to consist of the g.s., Jπ = 1/2+, and a level at 0.2771 MeV, Jπ = (11/2−). Efforts have been made to indicte apparent discrepancies in the data. The present compilation might serve as a basis for choosing definitive experiments to augment our knowledge of nuclei in this mass chain.

Nuclear Data Sheets for A = 75*

Abstract The literature pertaining to nuclei with A = 75 has been reviewed, and a summary of the nuclear structure properties is presented here. This compilation marks a departure from the Nuclear Data Sheets style in that: 1) Emphasis is placed upon summaries of the nuclear structure information rather than compilation of all the data. 2) Complete data sets for each type of reaction are stored in the Evaluated Nuclear Structure Data File (ENSDF) at the Nuclear Data Project, but only portions of the data are included here. 3) The complete compilation, i.e., drawings, data sheets, and references, has been produced from computer files. 4) Comments have been kept to a minimum, thus leaving it to the reader to refer to the original work for fine details. 5) The compilers have not included all nuclear quantities that could be deduced from the data, e.g., transition matrix elements, parameters for suggested rotational bands, etc. The 74Se(n,γ) data have been reinterpreted by the compilers and a neutron separation energy of 8027.4 keV 15is suggested for 75Se. All Q—values have been adopted from the compilation of Wapstra et al. (74WaBG) except as noted. It is hoped that researchers who generate data which are superior to those which were available at the time of this compilation will submit their results to the Nuclear Data Project for inclusion in the ENSDF.

Nuclear data sheets for A = 173

Abstract The available experimental results for nuclei in the mass chain A = 173 are summarized. The evaluated data are compared with theory, where possible, and arguments for spin, parity, and Nilsson-state assignments are given. A probable discontinuity in the Nilsson ground-state systematics is noted for tantalum, consistent with strong beta transitions to a 1/2 − [521] configuration in 173 Hf. Similar decay properties were observed for 171 Ta (74HoHa).

NUCLEAR DATA SHEETS FOR A = 107.

Abstract All literature containing nuclear structure data pertaining to the mass chain A = 107 has been reviewed and evaluated. The main data have been summarized and used to construct level and decay schemes. Overall, the data only allow few definitive spin and parity assignments to be made. Inconsistencies in the data are noted either by direct comparison or in footnotes. The present compilation might serve as a basis for choosing definitive experiments that would augment our knowledge of nuclei in this mass chain. Data received prior to November 1971 have been included.

NUCLEAR DATA SHEETS FOR A = 121.

Abstract The literature has been surveyed for data pertaining to nuclei in the mass chain A = 121. Well over 200 papers and communications were considered, and information for approximately 100 has been included. The cutoff date was the end of February 1971. The data for this mass chain are rather fragmentary. Few spin assignments are firm. The half-life of the 8-keV isomer in 121 Sn is still very much in doubt. The characteristics of the levels in 121 Sb are not yet well defined, but the enhanced E2 component of the 66-keV transition between the 0.57308 (1/2 + ) and 0.50754 (3/2 + ) levels may imply a large deformation. There seems to be building a cumulation of evidence throughout the mass region A ≈ 100–140 indicating the presence of such a deformation at about 500–1000 keV of excitation. The present compilation might serve as a basis for choosing definitive experiments that would augment our knowledge of nuclei in this mass chain.