Study of the (n,γ) reaction in the mass region, A = 50–63

Abstract

The circular polarization of γ-rays from the capture-of polarized thermal neutrons in isotopically enriched targets of 50Cr, 52Cr, 54Fe, 60Ni and 62Ni has been measured. The analysis of 36 primary transitions resulted in unambiguous spin assignments for 30 levels. Eight of these have not been reported previously: 51 Cr ( E x = 4.64 MeV), J = 3 2 53Cr (3.62 MeV) , J π = 1 2 − 55Fe (2.03, 3.03, 3.79 and 4.50 MeV); J π = 3 2 −, 3 2 −, 1 2 − and 1 2 −; 61Ni (2.00 MeV) , J = 3 2 ; 63Ni (1.32 MeV) , J π = 3 2 − . They γ-ray energies and intensities of the transitions have been measured. The 50Cr, 52Cr, 54Fe, 60Ni and 62Ni (n,γ) reaction Q-values were determined to be 9262.0 ± 1.0, 7939.6 ± 0.9, 9297.8 ± 1.0, 7819.6 ± 0.8 and 6838.2 ± 0.7 keV, respectively. A significant correlation between the (d, p) and (n, γ) strength has been found for the 2 p 3 2 levels in even-odd nuclei, but not for the 2 p 1 2 levels.