Investigation of the photoneutron cross section in /sup 206/Pb and /sup 208/Pb from 9 to 16 MeV

Thesis/Dissertation · Tue Jan 01 04:00:00 EST 1985

OSTI ID:5552957

Morford, L J

The time of flight of photoneutrons from /sup 206/Pb and /sup 208/Pb was observed at scattering angles of 55/sup 0/, 90/sup 0/, and 125/sup 0/. Photons with energies between 9 and 16 MeV were used to excite the target nuclei. The incident photon beam was provided by the University of Illinois Tagged Photon Facility and had an effective energy resolution of around 400 keV. The total cross section for both /sup 206/Pb and /sup 208/Pb were well described by Lorentzian curves with widths of 4.12 +/- 0.24 MeV for /sup 206/Pb and 4.09 +/- 0.38 MeV for /sup 208/Pb. The peak positions of the curves were determined to be 13.7 +/- 0.06 MeV for /sup 206/Pb and 13.53 +/- 0.05 MeV in /sup 208/Pb. No angular asymmetry about 90/sup 0/ in the differential cross sections was detected in either element above 11 MeV. Below 11 MeV the asymmetry varied with energy between alternate positive and negative values for each element. The time-of-flight spectra could be parameterized for low energy neutrons by a statistical decay with a nuclear temperature of 0.9 MeV. There was an excess of high energy neutrons above this distribution. A more detailed analysis of the spectra using the Hauser-Feshbach formalism suggests that this excess is also from the statistical decay of the nucleus.

• Research Organization: Illinois Univ., Urbana (USA)
• OSTI ID: 5552957
• Country of Publication: United States
• Language: English

Related Subjects

651925* -- Nuclear Properties & Reactions
A=190-219
Experimental-- Nuclear Reactions & Scattering-- (-1987)
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ANGULAR DISTRIBUTION
CROSS SECTIONS
DATA
DIRECT REACTIONS
DISTRIBUTION
ENERGY RANGE
EXPERIMENTAL DATA
INFORMATION
KNOCK-OUT REACTIONS
LEAD 206 TARGET
LEAD 208 TARGET
MATHEMATICAL MODELS
MEV RANGE
MEV RANGE 01-10
MEV RANGE 10-100
NUCLEAR REACTIONS
NUMERICAL DATA
PHOTONUCLEAR REACTIONS
STATISTICAL MODELS
TARGETS
TIME-OF-FLIGHT METHOD