Measurement of partial radiation widths of high energy transitions from keV capture resonances in56Fe and58,60Ni

Abstract

High energy y-ray transitions to low-lying states following neutron capture in 56Fe and ss'6~ have been investigated for individual resonances in the neutron energy range 7-70keV using a 50cc Ge(Li)-detector. Partial radiation widths for s-and 1>0 wave resonances were determined. For the 1 >0 wave resonance in 58Ni at 47.8 keV a spin of 3/2 was derived. The y-ray strength for M1 transitions was found to be (21 __ 17)x 10 .9 and (16+7)x 10 -9 MeV -3 for 56Fe and 5SNi, respectively. The partial radiation widths of the studied s-wave resonances were compared with valence model calculations.

Investigation of the validity of the valence model for neutron capture in the mass range 40 < A < 70

“…In this way the validity of the valence model has been confirmed for the 5.64 keV resonance in 5°Cr [10] and for the 7.67 keV resonance in 54Fe [11]. At our laboratory partial radiation widths of high energy transitions for the 27 keV resonance in 56Fe, the 13.3 keV resonance in 6°Ni and the 15.4 and 63 keV resonances in S8Ni have been measured [12]. In these cases the valence model appears to predict only for the 6°Ni resonance at 13.3 keV the measured widths.…”