nuclear structure studies of neutron-rich nuclei produced

The wonderful environment provided by the Department of Physics and Astronomy at Vanderbilt University is very important to my four-year graduate life. University of Naples Federico II for discussions with them about the shell model and their work on the shell model calculations. I wish I could list all the people who have helped me over the past four years, but I can't.

The work at Vanderbilt University is supported in part by the U.S. Department of Energy under Grant and Contract Nos. Excitation energies of the 11/2+ states of the odd-A 133−141Cs versus those of the first 2+ states of the corresponding even -even Xe nuclei. Since then, the understanding of the structure of the nucleus has grown enormously, both in theory and in experiments, with enormous amounts of theoretical and experimental effort.

However, there is no single theory that has the ability to interpret all the rich variations of phenomena observed experimentally in nuclei. As new experimental techniques advance scientists' ability to study nuclei further and further away from stability, nuclear physics research has moved into more and more exotic fields, and new theoretical models have been needed to interpret new phenomena.

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6000 nuclei are predicted

The excitation energies can be in the form of collective rotations or vibrations of the entire nucleus. In the present work, we have investigated fast γ-ray spectroscopy of fission fragments produced in the spontaneous fission of 252Cf. The first step towards the collective model was made by Bohr and Mottelson in the 1950s.

In the strong coupling limit, the single particle adiabatically follows the rotation of the nucleus and the coupling to the deformation is much stronger than the perturbation caused by the Coriolis interaction. In the experiments of the β decay studies and heavy ion reactions, mass separation has been performed to identify a specific nucleus. Then one must rely on the known transitions in the fission partners of the nucleus of interest.

We measure the fission yield ratios of the two partner isotopes of the nucleus of interest at the gates located at the transitions. These parallel cascades form multiple excitation bands of the nucleus if they belong to the same isotope. The relative intensities of the γ-ray transitions also give us clues to place these transitions in the level scheme.

It is important to extend our knowledge of the structures of Rh isotopes to the more neutron-rich 114,115Rh. Spin-parity assignments are proposed for the observed levels based on the systematics of the odd-even Rh isotopes. The side band feeding the (8−) state in the yrast band is also a sign of the existence of.

The observation of anomalous signature splitting and signature inversion is a common feature in many massive regions. Theoretical calculations were performed based on the gear model with a triaxial shape [69], which predicted the existence of signature inversion in the A and 160 regions. Of course, the origin of the signature inversion in the A = 110 region is a good question for more experimental and theoretical work.

In the following model calculations, level energies in 115Rh are well reproduced as natural consequences of the triaxial deformation. The energies are in keV and the width of the arrow is proportional to the corresponding γ-ray intensity. The energies are in keV and the width of the arrow is proportional to the corresponding γ-ray intensity.

The energies of the excited states in 134I and 136I are relative to the (8−) state and the 7− state, respectively.

Figure 2.1: A schematic drawing for two successive γ-ray transitions in a cascade.

Then, the parity of the levels in the keV cascade is obtained from the total internal conversion coefficient (αT) of the 236.9-keV transition. Comparisons of the experimental αT value with the calculated values ​​indicate that the multipolarity of the 236.9-keV transition is M1 and/or E2. In view of the results in the above paragraph, the parity of the levels in the cascade should be positive.

In this figure, we have also reported the results of the actual shell model calculations, which will be discussed in the next subsection. The excitation energies of the first 5/2+ states and some other yrast states in these isotopes are shown in Figs. A brief discussion of the derivation of two-body matrix elements can be found in Ref.

Angular correlations are measured for the keV cascade in 134I to determine the spin parities of the states of interest. This work provided further evidence for the similarity of the spectroscopy of the N = 84 isotones whose structures can be described within the framework of the shell model. The spins and parities assigned to certain states are determined by measured angular correlations.

13, 107] and present calculations predicting a spin parity level of 1596.8 keV 10−. In this section we will give an interpretation of the level schemes of N = 83 isotones with a shell model. A Hamiltonian identical to that of previous shell model studies.

144], based on the observation of reverse sputtering of the odd-even effect in the differential radii in the Cs isotopes. The spin parity of the ground state of 146Pm was determined to be 3− in the β-decay studies without providing a configurational explanation. The present study enriches our knowledge of the variation of the electric dipole moments in the Cs isotopic chain and provides further evidence for the proposal in Ref.

60] that in the Cs isotopes there is a pronounced decrease in the electric dipole moments with increasing neutron number. 7.16, it is seen that the variation of the dipole moments in the above Cs isotopes follows those of Ba and La.

Table V.2: Angular correlations measured in 139 Cs. The theoretical A 2 and A 4 values of γ − γ angular correlations for a pure quadrupole → quadrupole cascade are included.