Nuclear Data Sheets. Section B最新文献

Nuclear structure data for mass 46 nuclei are compared and evaluated. A set of adopted level properties based on these data is presented for each nucleus. Spin and parity assignments could be made for most of the low-lying excited states of ⁴⁶Ca, ⁴⁶Sc, and ⁴⁶Ti. The data for ⁴⁶K and ⁴⁶V, which are more difficult to study, are naturally less complete. Uncertainties or inconsistencies in the data are noted.

The adopted level and decay properties are based on data received before April 1970.

Level schemes, spin and parity assignments, and decay properties are presented for all nuclei with mass number A = 47. Experimental data and adopted values are given along with conclusions as to the best spin and parity assignments. The presentation of the nuclear properties is given in the light of the data and current theoretical ideas. Inconsistencies in the data are discussed wherever they are noted by the compiler.

While a few levels in each of the A = 47 nuclei appear to be well represented as ‘shell model’ states, it is clear that there are may more low-lying complex states than have been accounted for by model calculations. As one views the nuclei from ⁴⁷K to ⁴⁷V it may be noted that simple shell properties deteriorate in the sense that (a) the single-particle strengths become increasingly fragmented, (b) the most strongly bound states become no longer the single-particle type (i.e., have small spectroscopic factors), and (c) the 2s_1/2, d_3/2, and 2p shell nucleons become increasingly important for the lowest levels as the proton and neutron numbers increase beyond 20 and decrease below 28, respectively.

The experimental data for A = 47 nuclei indicate the need for more measurements such as transition rates and multi-nucleon transfer reaction cross sections in order to determine the more complex nature of the low-lying levels. The gamma-ray properties in ⁴⁷Ca are poorly known, and only two levels in ⁴⁷K have been identified. Very little data exist on high-spin (J > 7/2) states expected in this region.

All the tabulated C²S and C²S direct-reaction strengths are derived from distorted-wave Born approximation reaction theory. The reader is referred to the individual papers for details of the calculations.

The adopted level and decay properties are based on data received before March 1970.

Level schemes and decay characteristics are presented for all nuclei with mass number 48. Experimental data, adopted values, comparisons with theory, and arguments for spin and parity assignments are given.

The adopted level and decay properties are based on data received before February 1970. Data received between February and April 1970 have been “Added in Proof.”

For all nuclei with A = 54 the available experimental data, which give information on the structure of these nuclei, are extracted from literature, compared, and evaluated. Inconsistencies in the data are presented. Among these, special attention is paid to the Q_β+-values of ⁵⁴Co and ^54mCo as they result from measurements on the β⁺-spectra and the (p,n) thresholds. From this Q_β+-value the log ft of the β⁺-transition of ⁵⁴Co to the ground state of ⁵⁴Fe is calculated. This log ft value gives information on the vector coupling constant of the β-interaction since a ΔT = 0, ΔJ = 0, Δπ = 0 super-allowed transition is involved. The resulting value for this log ft is compared with other known cases of this type of transition.

Comparison with theories and arguments for spin and parity assignments are given. Theoretical and systematical studies of these nuclei and their properties are (among others) given by: