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Neutron Induced Inelastic Cross Sections of 150Sm for En
R. O. Nelson
G. E. Mitchell
J. R. Cooper
C. Y. Wu
J. A. Becker
T. Kawano
N. Fotiades
W. Younes
M. Devlin
D. Dashdorj
P. E. Garrett
U. Agvaanluvsan
M. B. Chadwick
出版
United States. Department of Energy
, 2006
URL
http://books.google.com.hk/books?id=YnvgjwEACAAJ&hl=&source=gbs_api
註釋
Cross-section measurements were made of prompt gamma-ray production as a function of incident neutron energy (E{sub n} = 1 to 35 MeV) on an enriched (95.6%) {sup 150}Sm sample. Energetic neutrons were delivered by the Los Alamos National Laboratory spallation neutron source located at the Los Alamos Neutron Science Center (LANSCE) facility. The prompt-reaction gamma rays were detected with the large-scale Compton-suppressed Germanium Array for Neutron Induced Excitations (GEANIE). Neutron energies were determined by the time-of-flight technique. The {gamma}-ray excitation functions were converted to partial {gamma}-ray cross sections taking into account the dead-time correction, target thickness, detector efficiency and neutron flux (monitored with an in-line fission chamber). Partial {gamma}-ray cross sections were predicted using the Hauser-Feshbach statistical reaction code GNASH. Above E{sub n} {approx} 8 MeV the pre-equilibrium reaction process dominates the inelastic reaction. The spin distribution transferred in pre-equilibrium neutron-induced reactions was calculated using the quantum mechanical theory of Feshbach, Kerman, and Koonin (FKK). These pre-equilibrium spin distributions were incorporated into a new version of GNASH and the {gamma}-ray production cross sections were calculated and compared with experimental data. The difference in the partial {gamma}-ray cross sections using spin distributions with and without pre-equilibrium effects is discussed.
