Shell-model calculations

Using the shell model, calculate the ground-state spins, parities, and magnetic... 

Shell-Model Calculations near 132Sn Using a Realistic, Effective Interaction... 

STONE ET AL. Shell-Model Calculations near I32Sn... 

Conventional spherical shell model calculations have been undertaken to describe 90 88zr and 90 88y in these large scale calculations valence orbitals included If5/2 2P3/2 2Pl/2 and 199/2 The d5/2 orbital was included for 98Y and for high-spin calculations in 98Zr. Restrictions were placed on orbital occupancy so that the basis set amounted to less than 2b,000 Slater determinants. Calculations were done with a local, state independent, two-body interaction with single Yukawa form factor. Predicted excitation energies and electromagnetic transition rates are compared with recent experimental results. 

Spherical shell-model calculations were undertaken of these nuclei, in order to gain information on their nuclear structure. The calculations reported here were done with a local, state independent two-body interaction with a single Yukawa form factor,... 

If (n,y) equilibrium is achieved, then the abundances will be determined by the beta-decay rates of unmeasured nuclei far from stability. Although some progress has been made [KLA81, TAK85] in shell model calculations of these rates, further studies are warranted. 

Shell-Model Calculations of /3-Decay Rates for s- and r-Process Nucleosyntheses... 

Examples of large-basis shell-model calculations of Gamow-Teller 6-decay properties of specific interest in the astrophysical s-and r- processes are presented. Numerical results are given for i) the GT-matrix elements for the excited state decays of the unstable s-process nucleus "Tc and ii) the GT-strength function for the neutron-rich nucleus 130Cd, which lies on the r-process path. The results are discussed in conjunction with the astrophysics problems. 

Reliable predictions of unknown 6 transition rates in heavy nuclei can be extremely difficult even for rather well-known nuclei. In what follows, we present some examples of large-basis shell-model calculations for such unknown 6 decays. 

TAKAHASHIET al. Shell-Model Calculations of fi-Decay Rates... 

Since most nuclei in the region of deformation at A 100 can only be produced with rather low yields which makes detailed spectroscopic studies difficult, we have examined possibilities of extracting nuclear structure information from easily measurable gross 13-decav properties. As examples, comparisons of recent experimental results on Rb-Y and 101Rb-Y to RPA shell model calculations using Nilsson-model wave functions are presented and discussed. 

The unusual features of the A=100 nuclei briefly reviewed above continue to stimulate strong interest in the structure of these nuclei. Theoretical studies, including potential energy and microscopic shell model calculations, as well as a more detailed review of the features of the A=100 region than space here permits, are discussed in [PET85]. 

A cranked shell-model calculation for gave a - 80 keV negative... 

For the positive parity states, the population of the 0+ 6+ states follows (2J+1) which indicates that these states are consistent with being an (f7/2)2 multiplet. As can be seen in Fig. 1, the spectrum of the (12C,11C) reaction leading to Nd enhances h9/2 transfer. Comparison of the (16q,15o) and (12C,nC) spectra clearly shows that the 8+ state at 2.709 MeV is primarily an f7/2 h9/2 configuration. Unfortunately, there are no extensive shell model calculations with..which to compare these results. 

In summary, the selectivity of certain heavy ion reactions have been used to identify two proton and two neutron states of high spin (both yrast and non-yrast) in Nd nuclei The first direct information about the configurations of some of these states has been obtained and the results suggest simple configurations for some but not all of them At the same time certain members of the neutron 7/2 13/2 multiplet are not seen and comprehensive shell model calculations would be very useful to determine the reason Heavy ion induced transfer reactions, if chosen carefully are valuable spectroscopic tools,... 

Shell model calculations predict a quasi-shell closure at 96Zr. Therefore, it is of interest to measure g-factors of states in 97Zr and test whether they can be described by simple shell model configurations. The 1264.4 keV level has a half-life of 102 nsec, and its g-factor was measured by the time-differential PAC method at TRISTAN [BER85a]. The result, g-0.39(4), is consistent with the Schmidt value of 0.43, which assumes no core polarization and the free value for the neutron g factor, g g free. This indicates that the 1264.4 keV level is a very pure single-particle state, thus confirming the shell model prediction of a quasi-shell closure at 96Zr. 

In the original paper [35], these values are compared to previous experimental and theoretical determinations. Many early shell model calculations and several experiments yielded much too large rumpling values. In most cases, this can be attributed to an inadequate substrate preparation, i.e. 

Among the microscopic models, the most accurate one for the presupernova and supernova calculations is the shell model. Over the years very large space shell model calculations for nuclei in the /p-shell were found to very successful and weak interaction rates have been calculated extensively using the shell model results [27,6]. 

Shell model calculations in the /p-shell using the modified Kuo-Brown (KB3) interaction with the valence orbits /7/2) 7 3/2) 7 1/2 and /s/2 have been carried out using the Strasbourg-Madrid [28] code. They reproduce the experimental spectra well. Information on the GT matrix elements come from the (p, n) and (n,p) reactions for the / and f3+ decays. Calculations for GT... 

CsF is the only alkali halide with rocksalt structure in which the cation makes the greater contribution to the electronic polarizability. Although there have not been any Shell Model calculations on this material, its mirror compound Nal should provide at least some guide as to the energetics of... 

The effects of relaxation on the calculated surface phonon dispersion in Rbl have apparently been verified, particularly by the observation of a surface optical mode which lies above the bulk phonon optical bands. Except for the mysterious acoustic band mode in Rbl, the Shell model calculations have generally been quite accurate in predicting surface vibrational mode energies in both high-symmetry directions of the alkali halide (001) surfaces. 

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