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.

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