GAMMA RAYS ASSOCIATED WITH FISSION
Measurements of the energy spectra and time distribution of the fission-associated gamma rays are described. New data for thermal neutron-induced fission in U/sup 235/ is presented covering the energy range between 0.3 and 8.0 Mev. Gamma-ray energy analysis was carried out with a multiple-crystal scintillation spectrometer employing either Compton scattering of pair production to give unique pulse-height response. The importance of unique spectrometer response is explained. The gamma-ray spectrometer was operated in coincidence with a spiral-wound fission chamber by the use of a four-fold coincidence circuit having a resolving time of 6 x 10/sup -8/ sec. Spectral measurements for delayed fission radiation were obtained with a similar gamma-ray spectrometer. Energy distributions from 0.3 to 5.4 Mev are presented for ten delay times between 1.7 and 1550 sec. Gamma radiation delayed between 6 x 10/sup -8/ and 3 x 10/sup -6/ sec after fission was observed following thermal-neutron induced fission. This radiation appeared to be about 6% as intense as the prompt radiation. No gamma-rays in the range from 3 to 7 x 10/sup -6/ sec were observed within limitations imposed by random backgrounds. No measurements were reported in the time range between 7 x 10/sup 6/ sec and 1 sec. New data presented include time time dependence of the gamma radiation delayed from 1 to 1600 sec after fission, divided into six gamma-ray energy intervals betwveen 0.28 and 5.0 Mev. These data are in good agreement with the energy-spectral data. Comparisons are also made with data available from gross fission-product photoneutron yields and chemically separated fission-product nuclides. (auth)
- Research Organization:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- Sponsoring Organization:
- USDOE
- NSA Number:
- NSA-12-015133
- OSTI ID:
- 4325517
- Report Number(s):
- A/CONF.15/P/670
- Resource Relation:
- Other Information: Prepared for the Second U.N. International Conference on the Peaceful Uses of Atomic Energy, 1958. Orig. Receipt Date: 31-DEC-58; Related Information: Presented at the Second United Nations Conference on the Peaceful Uses Of Atomic Energy, June 1958.
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
BACKGROUND
COINCIDENCE METHODS
COMPTON EFFECT
CRYSTALS
DISTRIBUTION
ENERGY
ENERGY RANGE
FISSION
FISSION CHAMBERS
GAMMA RADIATION
GAMMA SPECTROMETERS
MEASURED VALUES
PAIR PRODUCTION
PHOTONEUTRONS
PULSE ANALYZERS
RESOLUTION
SCATTERING
SCINTILLATION COUNTERS
SPECTRA
THERMAL NEUTRONS
URANIUM 235