High Resolution Photofission Measurements and Intermediate Structure in THORIUM-232.
Abstract
The photofission cross section of ('232)Th was measured in the energy range 5.8 - 12 MeV with an average photon energy resolution of 600 eV. The gamma rays, variable in energy, were obtained from narrow (p,(gamma)) resonances in various nuclei. Intermediate structure was observed at subbarrier excitation energies. The average spacing of photofission resonances provided the first relatively direct determination of the energy of the second minimum of the fission barrier, relative to the ground state. The measured fission probability and various properties of the intermediate structure were found to agree with calculated values based on a double humped fission barrier. The features of this barrier, a rather high first hump and a deep secondary well, are quite different from the predictions of current theoretical barrier calculations.
- Publication:
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Ph.D. Thesis
- Pub Date:
- 1986
- Bibcode:
- 1986PhDT........12Z
- Keywords:
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- Physics: Nuclear