Isobaric analogue states excited in the59Co(p, ?)60Ni reaction

Abstract

Abstract. The 59Co(p, 7)('~ reaction has been investigated in the proton energy region Ep= 1365-2 150 keV. Decay schemes and branching ratios have been determined for ten resonances, five of which have been identified as possible analogues or fragments of analogues of the ground state (5 +) and the 58.6 keV (2+), 277.1 keV (4+), 288.4 keV (3+), and 435.7 keV (5 +) levels in 6~ At eight of the resonances most of the decay seems to go via a group of states with an excitation energy of 5 -9 MeV. The investigated analogue states give a Coulomb displacement energy of 9 118 +_ 7 keV.

55Co Level Properties

“…together with results from recent experiments. Excitation energies and branching ratios are in agreement with recent data [3,4,12,131. For the 2 166, 2 565, 2 659, 2919, 2 939, 3 303, 3 642, 4 165, 4 721 and 5 172 keV levels the analysis of the decay is straightforward and does not give rise to any ambiguities.…”

“…The gamma-ray line observed at 1 158 keV may contain a contribution from the 1160 keV transition between the 3 725 and the 2 565 keV levels. The 3 725 keV level is reported [4] to have a strong ground-state transition. Neither feeding nor decay of this level can be observed in subgroup 1 (Fig.…”

“…We obtain, however, a maximum contribution of lOo/h to the 1 158 keV intensity from the 1 160 keV transition. This upper limit was calculated from the known branching ratios of the 3 725 keV level [4] and the estimated upper limit (two standard deviations) of the ground-state transition intensity. The intensity of the 758 keV line is strong compared to the results of refs.…”

“…Level properties have been reported from many types of experiments, such as (p,.) [1][2][3][4], (d,n) (3He,d) [8-131, (cr,t) [14] and (p,r) [15, 161. A number of these investigations [IO-131 have utilized the powerful technique of recording the emitted gamma radiation in coincidence with outgoing particles.…”

“…The present work utilizes the (d,n:/) reaction, which selectively populates single-particle states of both isospins. The gamma-ray spectra in coincidence with various neutron groups have been analysed in parallel with data from (p,y) experiments [4].…”