Photofission of actinide nuclei in the quasideuteron and lower part of theΔenergy region
| Autor: | J. M. Vogt, V. G. Nedorezov, N. R. Kolb, B. L. Berman, Philip L. Cole, A.S. Sudov, J.C. Sanabria, G.Ya. Kezerashvili, Gerald Feldman, C. Cetina, R. E. Pywell |
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| Rok vydání: | 2000 |
| Předmět: | |
| Zdroj: | Physical Review C. 61 |
| ISSN: | 1089-490X 0556-2813 |
| DOI: | 10.1103/physrevc.61.034604 |
| Popis: | The total photofission cross sections for the actinide nuclei ${}^{232}\mathrm{Th},$ ${}^{233}\mathrm{U},$ ${}^{235}\mathrm{U},$ ${}^{238}\mathrm{U},$ and ${}^{237}\mathrm{Np}$ have been measured from 68 to 264 MeV using tagged photons at the Saskatchewan Accelerator Laboratory. The fission fragments were detected using parallel-plate avalanche detectors. The results show that the fission probability for ${}^{238}\mathrm{U}$ is 20% lower than that for ${}^{237}\mathrm{Np}$ and 40% higher than that for ${}^{232}\mathrm{Th}.$ Less significant differences were also found among the individual uranium isotopes. These results contradict the assumption that the fission probability for ${}^{238}\mathrm{U}$ is approximately equal to unity in this energy range. It has also been observed that the fission probability as a function of energy for all these isotopes is constant, with the exception of that for ${}^{232}\mathrm{Th},$ which increases with energy, although it seems to be reaching a saturation value. Comparison between the total photofission cross section for ${}^{237}\mathrm{Np}$ and the photoabsorption cross sections for lighter nuclei shows a behavior consistent with a broadening of the $\ensuremath{\Delta}$ resonance with increasing atomic mass. |
| Databáze: | OpenAIRE |
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