Search

Abstract: A general technique that corrects -ray gated decay-curve data for detector pulse pile-up is presented. The method includes corrections for non-zero time-resolution and energy-threshold effects in addition to a special treatment of saturating events due to cosmic rays. This technique is verified through a Monte Carlo simulation and experimental data using radioactive beams of implanted at the center of the -ray spectrometer at the ISAC facility at TRIUMF in Vancouver, Canada. The -decay half-life of obtained from counting 1809-keV -ray photopeaks emitted by the daughter was determined to be following a correction for detector pulse pile-up. This result is in excellent agreement with the result of a previous measurement that employed direct counting and demonstrates the feasibility of high-precision -decay half-life measurements through the use of high-purity germanium -ray detectors. The technique presented here, while motivated by superallowed-Fermi decay studies, is general and can be used for all half-life determinations (e.g. -, -, X-ray, fission) in which a -ray photopeak is used to select the decays of a particular isotope. [Copyright &y& Elsevier]

The properties of high-K isomers have been investigated by measuring γ rays from a source of the 31-year 178Hfm2 isomer and from the decay of implanted 178, 179Lu beams. Low-intensity transitions have been identified in the decay of 178Hfm2, demonstrating a consistent extension of K-hindrance systematics to higher multipolarities, and elucidating the spin-dependence of the mixing between the two Kπ = 8- bands. A search is underway for new isomers in 178, 179Lu and the preliminary results of the analysis are reported. [Copyright &y& Elsevier]