Analysis of an Experiment on Neutron-rich Isotopes

The structure of neutron-rich nuclei far from stability is of particular interest in evaluating theoretical models of the nucleus. Recently the neutron-unbound nucleus of $^{28}$F was produced via one-proton stripping from a $^{29}$Ne beam at the National Superconducting Cyclotron Laboratory at Michigan State University; this nucleus is one neutron away from the magic number N=20. In addition to $^{28}$F, other isotopes were produced from secondary fragmentation of $^{32}$Mg, the primary beam contaminant. Since $^{28}$F is neutron-unbound in its ground state, it immediately decays in to a neutron and $^{27}$F. The CAESAR CsI array surrounded the $^{9}$Be reaction target to measure gamma-rays emitted from $^{27}$F in a bound excited state. The outgoing charged particle and decay neutron were measured in coincidence. The neutrons were detected by the MoNA, and the charged fragments were swept by a magnet into a series of charged particle detectors. The analysis requires separation and identification of both charged particles and neutrons. The isotope identification for charged particles is obtained from time-of-flight measurements after correction up to the fourth order for dispersive angle and position after the magnet. This isotope separation technique and current analysis status will be presented.