Nuclear-Reaction Studies in the Strontium Isotopes: TheSr88(d,p)Sr89Reaction

The ${\mathrm{Sr}}^{88}\mathrm{}(d,p)\mathrm{}{\mathrm{Sr}}^{89}$ reaction has been studied at 7.0 MeV using the MIT-ONR Van de Graaff generator and the multiple-gap spectrograph. Eighty-five levels in ${\mathrm{Sr}}^{89}$ below 5.86-MeV excitation were identified, compared with the 12 levels below 4.1-MeV excitation recorded previously from ($d,p$) studies. Among the 85 levels observed, 28 were populated by direct stripping transitions, and the data were used for determining the detailed fractionization of the single-particle strength in this energy region. A distorted-wave Born-approximation analysis was performed in these cases to determine the values of the orbital angular momentum $l_n$ and spectroscopic strengths $\mathrm{}(2J+1)\mathrm{}{S}_{l_n,j}$ for the transferred neutron. Sum-rule strengths were subsequently calculated and compared with shell-model limits. Detailed angular distributions for some of the nonstripping states are also presented. An averaged strength function for these weaker transitions is shown and is discussed in terms of possible intermediate structure.