On 1f2pNuclei. Seniority-three States of thev(2p_3/2, 1f_5/2, 2p_1/2)³Configuration in⁵⁹Ni

Abstract

On lf2p nuclei. Seniority-three states of the V ( ~P ~; ~, 1 f512, 2 ~~1 ~) ~ configuration in 69Ni.

Investigation of levels in59Ni following the ?+ decay of59Cu

“…An exactly similar broad peak has also been reported by Van Patter et al [-2]. A more striking evidence is obtained from a critical examination of the 56Fe + c~ reaction data [6]. There is a pair of weak y-rays at 1679.6 and 1689.2keV in the y-ray spectrum from the 56Fe + ~ reaction study [6], which was not assigned by the authors to any nucleus.…”

“…They also measured the mean lifetime v for 1428 keV 7-ray to be > 1 ps which is comparable to the Weisskopf estimate of 10 ps for an E2 transition of this energy. Monseu et al [6] and Pichever et al [4] confirmed the above assignment. The measurements of the yield function, the angular distribution and the linear polarisation of the fairly intense 1428.1keV transition result in the unique assignment 9/2--5/2-(pure E2).…”

“…It is interesting to note the presence of a y-ray at 1224.1 keV in the spectrum with an intensity four times that of the 1689.2keV y-ray and the energy difference (1689.2 -1224.1) 465.1 keV being identical with second excited state in 59Ni. The possibility of confusing this 1224.1keV y-ray with the 1226(2414.6-1188.6)keV transition is completely ruled out in this experiment [6] by the conspicuous absence of the 1536.9 (2414.6 -878) keV y-ray indicating that the 2414.6keV 3/2-state was not excited. In fact, 1536.9 keV y-ray appears with an intensity 1.66 times stronger than the 1226 keV y-ray in the 59Cu decay spectrum, where 2414.6keV level is excited.…”

“…A more striking evidence is obtained from a critical examination of the 56Fe + c~ reaction data [6]. There is a pair of weak y-rays at 1679.6 and 1689.2keV in the y-ray spectrum from the 56Fe + ~ reaction study [6], which was not assigned by the authors to any nucleus. It is interesting to note the presence of a y-ray at 1224.1 keV in the spectrum with an intensity four times that of the 1689.2keV y-ray and the energy difference (1689.2 -1224.1) 465.1 keV being identical with second excited state in 59Ni.…”

“…These facts make Vervier's initial assignments somewhat doubtful. However, in the recent study of 56Fe(c~, n)59Ni reaction, Monseu et al [6] report two distinct 7-rays at 1744.7 _+ 0.3 and 1749.8 _+ 0.5 keV the former being assigned to the excited state of 59Co excited through (e, p) reaction. The latter 7-ray at 1749.8keV which has not been assigned to any particular nucleus by the authors is not far from the 1748 keV reported in earlier 5SNi(d, p)S9Ni reaction studies [1(~12].…”