DELAYED GAMMAS FROM FAST-NEUTRON FISSION OF Th$sup 232$, U$sup 233$, U$sup 235$, U$sup 238$, AND Pu$sup 23$$sup 9$
Results of an experiment are presented in which the energy- and time- dependence of gammas emitted after instartaneous fast-neutron-induced fission of / sup 232/Th, /sup 233/U, /sup 235/U, /sup 238/U and /sup 239/Pu were measured, Gammas having energies between 0.12 and 6.5 Mev were detected during five short time intervals between 0.2 and 45.0 sec after fission occurred. The measured spectra and seventeen bin distributions of the absolute number of photons/fission- secMev and intercomparisons and integrations over energy and time of these distributions are given. The rate of energy emission from the products of /sup 232/Th + n was found to be 4.5 times higher than that from /sup 239/Pu + n during the first time interval after fission. Delayed gamma spectra from the products of /sup 232/Th + n are noticeably harder than those from /sup 239/Pu + n during all five time intervals measured. The several uranium isotopes' behavior is intermediate to that of the products of /sup 232/Th + n and /sup 239/Pu + n in both rate of energy emission and hardness of energy spectra. The significant differences in the measured characteristics of the delayed gammas from the five fissionable isotopes permit the isotopes to be arranged in a sequence. Approximate position in the sequence depends on the average displacement of the initial fragment distribution from fission. It appears possible to predict approximate values of delayed neutron yield, which Keepin has shown to also depend on the average displacement of the intial fragment of distribution from fission, of other fissionable isotopes on the basis of delayed gamma measurements. (auth)
- Research Organization:
- Los Alamos Scientific Lab., N. Mex.
- NSA Number:
- NSA-18-021296
- OSTI ID:
- 4008707
- Report Number(s):
- LADC-4730; 0031-899X
- Journal Information:
- Physical Review (U.S.) Superseded in part by Phys. Rev. A, Phys. Rev. B: Solid State, Phys. Rev. C, and Phys. Rev. D, Vol. Vol: 134; Other Information: LADC-4730. Orig. Receipt Date: 31-DEC-64
- Country of Publication:
- United States
- Language:
- English
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