Half-lives and delayed neutron emission probabilities of neutron-rich Li--Al nuclides (US)

Beta-decay half-lives and delayed neutron emission probabilities of very neutron-rich nuclides from Li to Al have been measured by a delayed coincidence technique. Neutron-rich nuclides were produced by reaction of 800-MeV protons on a 232Th target and were individually identified by use of the time-of-flight isochronous spectrometer. For 16 previously measured nucides, the half-lives determined here agree with literature values within the uncertainties. The previously unmeasured half-lives for 25F (59±40 ms) and 28Ne (14±10 ms) have been determined. Delayed neutron emission has been measured for 12Be, 14B, 17C, 18N, 25F, and 28Ne. Emission probabilities are reported for 19 precursors and upper limits are reported for 12 other nuclides. These data are compared with predictions of several beta-decay models