$\beta$ decay of $^{51,52}$Ar

The neutron-rich $^{51,52}$Ar isotopes were produced by fragmentation of a $^{76}$Ge primary beam of energy 130 MeV/A at NSCL. The A1900 fragment separator, with a wedge degraded and plastic scintillator placed at its intermediate image, was used to select the Ar isotopes of interest from other reaction products. The full 5\% momentum acceptance of the A1900 was used, and other neutron-rich isotopes of K, Ca, Sc, and Ti were available for study as well. Seven implantations unambiguously identified as $^{52}$Ar based on energy loss, total energy, time-of-flight, and magnetic rigidity provided first evidence for the existence of this nuclide. We will report the $\beta$-decay half-lives of $^{51,52}$Ar deduced from event-by-event time correlations between implantations and subsequent $\beta$ decays measured with the NSCL Beta Counting System.