Nuclear Data Sheets. Section A最新文献

Graphs are presented of the binding energy of two neutrons as a function of N, of two protons as a function of Z, and of alpha-particle decay energy as a function of N. The range covered is Z = 10 to 102 and N = 10 to 154. Values shown are based on a 1964 mass adjustment.⁹

Recent measurements of the most probable kinetic energy release in fission are compared in order to study the dependence on nuclear species. Appropriate corrections to data obtained with semi-conductor detectors, particularly with regard to calibration procedures, are discussed and applied. Corrected results are listed in Table I and plotted in Fig. 1. It is found that the most probable kinetic energy release in fission can be simply expressed by the function. $<E_k>=0.1071Z^2/A^{1/3}+22.2MeV.$

The corrected <E_k> values are compared with recent liquid drop calculations and good agreement is found for Z²/A less than 35, but not above this value. Effects of mass asymmetry are also briefly discussed. Analysis of the data indicates that the most probable kinetic energy release is essentially independent of excitation energy. Use was made only of results published since 1961. Prior data can be found in the review of Huizenga and Vandenbosch.

Adopted values for the reduced electromagnetic transition probability, B(E2)_ex, from the ground to the first-excited 2⁺-state of even-even nuclei are given in Table I. Values of β₂, the quadrupole deformation parameter, and of T, the mean life of the 2⁺ state, are also listed there.

Table II presents the data on which Table I is based, namely the experimental results for B(E2)_ex values with quoted errors. The literature has been covered to January 1965.

The ratio of the value of β₂ to values expected from the single-particle model is presented graphically as a function of neutron number. As an indication of the extent of collective features in nuclear structure, this ratio seems a better measure than the value of β₂ itself.

A tabulation is presented of experimentally measured values of internal-conversion coefficients for the K-shell, α_K, L-subshells (mostly ratios only, L₁:L₂:L₃), and for all shells, α_total. Results reported prior to November 1965, whose uncertainties are ≦ 25%, are listed and compared with theoretical values. Transition energies and spins an parities of initial and final levels, when known, are included. The theoretical values were obtained from computer interpolation, and in some cases extrapolation, of the tables of Sliv and Band. A brief discussion of the methods of measuring conversion coefficients is given.

Nuclear cross sections for charged-particle-induced reactions of isotopes of Li, Be, and B are presented in tabular and graphical form. This compilation includes experimental cross-section data available in the literature before January 1, 1964, for nuclear reactions of the type A(a,b)B at all energies, where M_a ≧ one nucleon mass. Nuclear reactions involving mesons in the exit channel are not included. This collection supplements a previous compilation, Los Alamos Scientific Laboratory Report LA-2014 (see following page for bibliographic information). A large amount of the cross-section data is not presented either in tabular or graphical form in order to limit the size of the present compilation to a manageable one. A number of annotated bibliographies are included in the appendixes to provide a brief summary of these data.