NUCLEAR STATES WITH HIGH ANGULAR MOMENTA AND THEIR STABILITY
A general survey was made of the dependence of the energy of the lowest nuclear state with a specified high angular momentum on that angular momentum, based on four different models. In addition the stabiltty of states with high angular momenta is studied. In all applications of the shell model attention was limited to closed shell nuclei or to nuclei which are idealized to be closed shell nuclei. The calculated energy of the lowest state was found to depend approximately quadratically upon angular momentum. The constant of proportionality defined an effective moment of inertia. The moments thus found for all four models did not appreciably differ from that of a rigid body, in accord with Bloch's findings. Coulomb energy was neglected, and equal numbers of protons and neutrons were assumed. Consequently the results do not apply to heavy nuclei, where high angular momentum combined with high charge can bring about a big deformation and cause fission. The nuclei under scrutiny are considered to have cylindrical symmetry. The axis of symmetry is identified with the angular momentum vector. An expression for the equilibrium configuration for the lowest state of a nucleus with a specified angular momentum, as well as an expression for the dependence of energy on angular momentum were derived on the basis of the liquid drop model, the Fermi gas model with the nucleons moving in a square well potential with a supplementary surface tension energy proportional to the surface area of this deformed potential well, the Fermi gas model with the individual nucleons moving in a harmonic oscillator well, and the shell model with a harmonic oscillator potential. In addition, the stability of exited rotating nuclei was investigated with regard to heavy particles emission and gamma radiation. Finally, a way is suggested to estimate the energy of lowest state of a specified angular momentam from observations on the density of exited states of the same angular momentum, as in experiments on slow neutron capture. In principle such slow neutron experimentation on a number of nearby nuclei of known spins should eventually allow one experimentally to determine the dependence of energy on angular momentum.
- Research Organization:
- Princeton Univ., N.J.
- NSA Number:
- NSA-16-023036
- OSTI ID:
- 4823149
- Journal Information:
- Dissertation Abstr., Vol. Vol: 22; Other Information: Orig. Receipt Date: 31-DEC-62
- Country of Publication:
- Country unknown/Code not available
- Language:
- English
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