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The β-decay half-lives of [128][129][130] Cd have been measured with the newly commissioned GRIFFIN γ-ray spectrometer at the TRIUMF-ISAC facility. The time structures of the most intense γ-rays emitted following the β-decay were used to determine the half-lives of 128 Cd and 130 Cd to be T 1/2 = 246.2(21) ms and T 1/2 = 126(4) ms, respectively. The half-lives of the 3/2 + and 11/2 − states of 129 Cd were measured to be T 1/2 (3/2 + ) = 157(8) ms and T 1/2 (11/2 − ) = 147(3) ms. The half-lives of the Cd isotopes around the N = 82 shell closure are an important ingredient in astrophysical simulations to derive the magnitude of the second r-process abundance peak in the A ∼ 130 region. Our new results are compared with recent literature values and theoretical calculations.

The Gamma-Ray Infrastructure For Fundamental Investigations of Nuclei, GRIFFIN, is a new experimental facility for radioactive decay studies at the TRIUMF-ISAC laboratory. The performance of the 16 highpurity germanium (HPGe) clover detectors that will make up the GRIFFIN spectrometer is reported. The energy resolution, efficiency, timing resolution, crosstalk and preamplifier properties of each crystal were measured using a combination of analogue and digital data acquisition techniques. The absolute efficiency and add-back factors are determined for the energy range of 80 -3450 keV. The detectors show excellent performance with an average over all 64 crystals of a FWHM energy resolution of 1.89(6) keV and relative efficiency with respect to a 3"x3" NaI detector of 41(1)% at 1.3 MeV.

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The objective of this study was to determine the most efficient means of sampling faeces of finisher pigs for accurate and precise farm-level estimates of antimicrobial resistance among faecal Escherichia coli. Resistance to tetracycline and gentamicin of 8250 isolates of E. coli from 55 finisher pigs on one farm was measured with a hydrophobic grid membrane filter method. The between-pig, within-pen component of variance in resistance was large (97.5%), while between-pen, within-room and between-room components were small (2.5% and 0%, respectively). Using these resistance data, the abilities of two sampling strategies to estimate prevalence were modelled with a Monte Carlo 'bootstrap' procedure. Compositing faecal samples from several pigs before testing produced unbiased and precise estimates of prevalence and is simpler technically than individual animal testing.

The half-life of the superallowed Fermi β + emitter 14 O has been determined via simultaneous direct β and γ counting experiments at TRIUMF's Isotope Separator and Accelerator (ISAC) facility. A γ -ray counting measurement was performed by detecting the 2312.6-keV γ rays emitted from an excited state of the daughter 14 N following the implantation of samples at the center of the 8π γ -ray spectrometer, a spherical array of 20 high-purity germanium (HPGe) detectors. A simultaneous β counting experiment was performed using a fast plastic scintillator positioned behind the implantation site with a solid angle coverage of ∼20%. The results, T 1/2 (β) = 70.610 ± 0.030 s and T 1/2 (γ ) = 70.632 ± 0.094 s, form a consistent set and, together with eight previous measurements, establish a new average for the 14 O half-life of T 1/2 = 70.619 ± 0.011 s with a reduced χ 2 of 0.99.