Neutron Capture from $^{87}$Sr

The neutron-capture resonances of the reaction $^{87}$Sr$(n,\gamma)^{88}$Sr are significant to nuclear astrophysics to estimate the neutron density during the $s$ process, whose path is split by the branching nucleus $^{85}$Kr, and for a possible use of the $^{87}$Rb-$^{87}$Sr chronometric pair to measure the age of our Galaxy. In addition, the $\gamma$ rays of the product nucleus $^{88}$Sr are of importance to nuclear structure and the study of the pygmy resonance observed earlier in $(\gamma,\gamma')$ measurements. We report results from a neutron-capture experiment on $^{87}$Sr carried out with the $4\pi$ BaF$_2$ array, DANCE, at LANL. Spin values of neutron resonances have been deduced using the multiplicity and angular distributions of the cascade $\gamma$ rays following the neutron capture.