Benchmarking a surrogate reaction for neutron capture using $^{171,173}$Yb($d,p\gamma$)

The surrogate reaction technique is an indirect way to determine cross sections by measuring a reaction that proceeds through the same compound nucleus. A neutron transfer reaction, such as ($d,p$) has the advantage over a direct ($n,\gamma$) measurement since it can be measured in inverse kinematics. To test the feasibility of using a ($d,p\gamma$) reaction as a surrogate for neutron capture, a benchmark experiment has been carried out with the goal to reproduce the known [1] neutron capture cross section ratio of $^{171}$Yb and $^{173}$Yb. The $^{171,173}$Yb($d,p\gamma$) reactions were measured using an 18.5 MeV deuteron beam from the 88-Inch Cyclotron at LBNL. The reaction protons were measured using the Si detector array STARS and coincident $\gamma$-rays were detected using 6 Ge Clover detectors (LiBerACE). Preliminary results comparing surrogate ratio with the measured ($n,\gamma$) cross section will be presented.\newline\newline [1] K. Wisshak et al, Phys. Rev. C \textbf{61}, (2000) 065801.