Triple correlations in the 58Ni(p, γγ) 59Cu and 62Ni(p, γγ) 63Cu reactions

Abstract

Approximately 50 resonances having a yield of greater than 100 gamma rays per μC were discernible from the 62Ni(p, γ) 63Cu reaction in the range of proton energy from 1100 keV to 1850 keV. Gamma-ray energy measurements obtained by utilizing scintillation and lithium-drifted silicon spectrometers yield 3.42±0.02 MeV and 6.14±0.02 MeV for the Q-value of the 58Ni(p, γ) 59Cu and 62Ni(p, γ) 63Cu reactions, respectively. The existence of intermediate states was observed in 59Cu at 0.49±0.01, 0.91±0.01, 1.38±0.02, 2.00±0.02 and 2.32±0.02 MeV; and in 63Cu at 0.67±0.01 and 1.55±0.02 MeV. Triple-correlation measurements were performed with a double sum-coincidence spectrometer at resonance energies of 1424, 1663 and 1715 keV for the 58Ni(p, γγ) 59Cu reaction and at resonance energies of 1374, 1414, 1507 and 1634 keV for the 62Ni(p, γγ) 63Cu reaction. These measurements permitted J π assignments of ( 1 2 ), 5 2 −, 5 2 −, 5 2 − and ( 3 2 −) or ( 5 2 −) to the intermediate states in 59Cu at 0.49, 0.91, 1.38, 2.00 and 2.32 MeV, respectively; and ( 1 2 ) and either ( 3 2 −) 5 2 −), or ( 3 2 +) to the intermediate states in 63Cu at 0.67 and 1.55 MeV, respectively. The E2/M1 amplitude ratios were obtained whenever possible from the correlation data.