The $\beta$ decays of $^{75,77}$Cu

The newly designed Low-energy Radioactive Ion Beam Spectroscopy Station (LeRIBSS) at the HRIBF was implemented in order to study properties of neutron-rich nuclei. Isotopes of interest are produced by proton-induced fission in a uranium carbide target. Ions are separated using the high-resolution injector magnet and delivered to LeRIBSS, which consists of a universal detector support and a new fast moving tape collector. Using negative ions and adjusting the high-resolution magnet slits and field allowed us to obtain high purity beams with good rate. In particular a rate of about 3000 pps was reached for $^{75}$Cu. Results of beta and beta-delayed neutron decay studies of $^ {75,77}$Cu will be discussed. Funded by DOE grant DE-FG02- 96ER41006.