Neutron radiative capture in Na, Al, Fe, and Ni has been measured from 100 eV to 200 keV with a 1.25-m-diam liquid scintillator detector at the Rensselaer LINAC Laboratory. Radiation widths were determined for those resonances whose neutron widths are well known, while the resonance capture areas (-wave neutrons, and from these data />-wave strength functions of (O.lOrLO.04) XlCr~4 and (0.04±0.03) X 10~4 were determined, respectively, for 58 Fe and 58 Ni. These strength functions are probably just upper limits to the true ^-wave strength functions and are an order of magnitude smaller than optical-model predictions.* Taken in part from the thesis submitted to Rensselaer Polytechnic Institute by R. W. Hockenbury in August, 1967, in partial fulfillment of the requirements for the Ph.D. degree.
A 20-cc lithium-drifted germanium detector has been used in conjunction with the R.P.I. Electron Linac Neutron Velocity Selector to examine the high-energy gamma-ray spectra arising from thermal and resonance neutron capture in mercury, and from resonance capture in tungsten. The effective gamma-ray energy resolution of 12-18 keV allowed 29 transitions to be examined in the energy range 4.67 to 8.02 MeV following capture of thermal neutrons and resonance neutrons of energy 34, 130, and 175 eV in 199 Hg (116 transitions in all). The spectra are interpreted in terms of levels in the compound nucleus 200 Hg. An analysis of the strengths of 88 El transitions indicates a Porter-Thomas distribution, the best fit being achieved-with a X 2 function with 0.96_o.i7 +0-24 degrees of freedom. The mean reduced partial radiation width for transitions to states in 200 Hg above the pairing energy gap is shown to be significantly higher than the corresponding mean width for transitions to collective states below the pairing energy. No such effect is obvious in the case of resonance capture in 183 W. A comparison between resonance capture in 198 Hg and 182 W, where no pairing energy gap exists, shows that the mean partial radiation width is a factor 4 larger for 198 Hg than for the highly distorted 182 W.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.