Analogous intruder behavior near Ni, Sn, and Pb isotopes

Neutron single-particle strengths at N=40 , 42: Neutron knockout from Ni68,70 ground and isomeric states

“…[41]. [45]. Using the branching reported by Mueller et al [44], the partial cross sections are 25(3) and 7(1) mb for the knockout to the 915-and 1517-keV states, respectively.…”

“…The much larger relative intensities observed in Ref. [45] for the γ rays at 1129 and 1319 keV relative to the 594-keV transition in the decay chain 69 Fe → 69 Co → 69 Ni with respect to the 69 Co → 69 Ni one imply that these transitions, most likely, depopulate low-spin states. The two transitions are observed in the present experiment without identification of feeding transitions in coincidence with them.…”

“…Note: The 602.4-keV transition could not be resolved from the 594-keV line in the present work. The decay branching ratio of the 1517-keV state was taken from Table I (first column) of Liddick et al [45]. When using the values reported by Mueller et al [44], all intensities must be scaled by a factor of 1.05 with the exception of the normalizing intensity of the 594-keV line and the intensity of the 602.4-keV line that is scaled by a factor of 1.70.…”

“…The nucleus 69 Ni has been previously studied using a number of techniques, i.e., isomeric decay [43], β decay [44,45], and through a (d,p) reaction on 68 Ni [46]. The information gathered in these investigations was used in conjunction with the present data to arrive at the level scheme of Fig.…”

“…A number of excited states were identified and a partial level scheme was proposed based on feeding in β decay, but assuming a 7/2 − ground state for 69 Co. A more recent study by Liddick et al [45] demonstrated that, while the ground state has a half-life of 0.18(2) s, a second isomeric state is also present in 69 Co that β decays to 69 Ni with a half-life of 0.75(25) s. No excitation energy has been measured for this isomer and a tentative (1/2 − ) spin-parity assignment was given. A comprehensive analysis of the γ -decay-tagged β-decay half-life was performed by Liddick et al, comparing the decay curves of γ rays from the β decay of 69 Co where (i) 69 Co was directly implanted and (ii) 69 Co was produced as the decay daughter of implanted 69 Fe [45]. The much larger relative intensities observed in Ref.…”