Non-statistical aspects of resonance neutron capture in 103Rh

Measurements have been made of high-energy neutron capture γ ray spectra from the 103Rh(n,γ)104Rh reaction for discrete resonances up to 850 eV and for unresolved regions up to 6 keV, with the aim of investigating the reaction mechanism. Spins of stronger resolved s wave resonances up to 1272 eV were assigned using low-energy capture γ rays, and in some cases also using high energy γ rays. A value of 6999.7 +- 1.5 keV was obtained for the neutron binding energy, in good agreement with previous measurements, and a level scheme was constructed for 104Rh states up to 1 MeV populated by primary transitions. The distribution of a sample of 1938 reduced partial radiation widths in spin 1 resonances was found to be in full agreement with the Porter-Thomas pediction, contradicting a previous report of a deviation. The averaged γ ray spectra up to 6 keV showed an enhancement in the region 6.0 to 6.2 MeV, confirming previous observations. No correlations were found between resonance reduced neutron widths and reduced partial radiation widths in any part of the γ ray spectrum. In particular the lack of a significant correlation for transitions in the 'bump' region which populate final states also observed in the (d,p) reaction disagrees with an earlier report. (author)