Resonance-Averaged (n,γ) Spectra and their Applications to Nuclear Structure
Because they populate final states without regard to the details of the nucleonic configurations, neutron-capture γ rays are ideally suited for locating essentially all the low-lying nuclear states whose spins lie within a few units of that of the capturing state. With the reduction of the Porter-Thomas fluctuations through the use of neutrons having an energy distribution broad enough to average over a finite (and large) number of capture resonances, the primary capture γ -ray intensities can provide rather definite spin-parity information for those states which they are observed to populate. The power of these studies is greatly enhanced through the analysis of such resonance-averaged spectra at two distinct neutron energies, ~ 2 and ~ 24 keV, obtained from Sc and Fe neutron “filters”, respectively. In this paper, the use of resonance-averaged primary γ -ray spectra as a tool for low-energy nuclear spectroscopy is discussed and its strengths and limitations pointed out. Examples are drawn from studies of 2- and 24-keV neutron capture in samples of 154, 156, 157, 158Gd and 238U.
KeywordsNite IAEA Plague Kroger
Unable to display preview. Download preview PDF.
- 1.“Neutron Capture Gamma-Ray Spectroscopy”, Proceedings of the International Symposium on Neutron Capture Gamma-Ray Spectroscopy, Studsvik, 11–15 August, 1969 ( IAEA, Vienna, 1969 ).Google Scholar
- 2.“Neutron Capture Gamma-Ray Spectroscopy”, Proceedings of the Second International Symposium on Neutron Capture Gamma Ray Spectroscopy and Related Topics, September 2–6, 1974, Petten, the Netherlands (Reactor Centrum Nederland, the Netherlands, 1975).Google Scholar
- 9.R. C. Greenwood, in Ref. 2, above, pp 323–340.Google Scholar
- 10.Nuclear Data Sheets 9, 273 (1973).Google Scholar
- 15.R. E. Chrien, M. L. Stelts, H. I. Liou, C. W. Reich and S. S. Malik, Bull. Am. Phys. Soc. 23, No. 1, 92 (1978).Google Scholar
- 17.G. Alaga, K. Alder, A. Bohr and B. R. Mottelson, Mat. Fys. Medd. Dan. Vid. Selsk. 29, No. 9 (1955).Google Scholar