How nuclear structure evolves as more neutrons or protons are added to the system is an important topic in nuclear physics. The single particle/hole spectroscopic factor (SF) measurement is a key tool and it provides information on how a state of a nucleus resembles an inert core with a single particle/hole. From systematically studying the SF values for a chain of isotopes, the evolution of nuclear structure can be observed. The neutron-rich nuclei near the N=50 closed shell region are of particular interest since they are synthesized in the rapid neutron-capture process (r-process). To obtain a more clear picture of the systematics of neutron-hole states in N=49 isotones, ⁸³Se and ⁸⁵Kr were produced through the one-neutron stripping (p,d) reaction to populate single-neutron-hole states. Through comparing deuteron angular distributions to reaction calculations, the one- neutron-hole SFs can be extracted. The experiment was performed at the National Superconducting Cyclotron Laboratory (NSCL) with 45.5 MeV/u ⁸⁴Se and ⁸⁶Kr beams that impinged on C₂H₄ targets. The charged-particle detector array, HiRA, was used to identify emitted deuterons and measure their angles and energies. Heavier recoils, ⁸³Se and ⁸⁵Kr, were identified and analyzed by the S800 Spectrograph. Two Micro-Channel plates (MCP) were placed upstream to trace the beam to provide better angular information of the deuterons with respect to the beam. In this talk, the particle identification maps, Q-value spectra and preliminary angular distributions will be presented.
This work is supported in part by the National Science Foundation and U.S. Department of Energy.