Studies of $N \approx 40$ Ni isotopes via neutron-knockout (nKO) and deep-inelastic (DI) reactions

V. BADER, T. BAUGHER, D. BAZIN, J.S. BERRYMAN, B.A. BROWN, C. LANGER, N. LARSON, S.N. LIDDICK, E. LUNDERBERG, S. NOJI, C. PROKOP, S.R. STROBERG, S. SUCHYTA, D. WEISSHAAR, S. WILLIAMS, NSCL/MSU, M. ALBERS, M. ALCORTA, P.F. BERTONE, M.P. CARPENTER, J. CHEN, C.R. HOFFMAN, F.G. KONDEV, T. LAURITSEN, A.M. ROGERS, D. SEWERYNIAK, S. ZHU, ANL, C.M. CAMPBELL, LBNL, H.M. DAVID, D.T. DOHERTY, U. of Edinburgh/ANL, A. KORICHI, CSNSM-IN2P3/ANL, C.J. LISTER, U. of Mass.-Lowell, K. WIMMER, Central Mich. U. --- Excited states in $^{68}$Ni were populated in 2nKO reactions at NSCL. Prompt $\gamma$ rays were detected with the GRETINA array located in front of the S800 separator. A hodoscope at the S800 focal plane captured the $^{68}$Ni ions, where isomeric decays could be correlated with prompt $\gamma$ rays. Decay of the first excited state, a $0^+$ isomer, was observed, confirming that its energy substantially differs from the literature value. Comparing the decay patterns of excited states with shell-model calculations provides insight into their underlying structure. Data from $^{70}$Zn + $^{208}$Pb DI reactions studied with Gammasphere provide results consistent with the 2nKO. Single-particle strengths are also under investigation in the odd-$A$ Ni isotopes via 1nKO reactions.