Half-life of the superallowed {beta}{sup +} emitter {sup 18}Ne

The half-life of $^{18}\\mathrm{Ne}$ has been determined by detecting 1042-keV \\ensuremath{\\gamma} rays in the daughter $^{18}\\mathrm{F}$ following the superallowed-Fermi ${\\ensuremath{\\beta}}^{+}$ decay of samples implanted at the center of the $8\\ensuremath{\\pi}\\ensuremath{\\gamma}$-ray spectrometer, a spherical array of 20 HPGe detectors. Radioactive $^{18}\\mathrm{Ne}$ beams were produced on-line, mass-separated, and ionized using an electron-cyclotron-resonance ionization source at the ISAC facility at TRIUMF in Vancouver, Canada. This is the first high-precision half-life measurement of a superallowed Fermi \\ensuremath{\\beta} decay to utilize both a large-scale HPGe spectrometer and the isotope separation on-line technique. The half-life of $^{18}\\mathrm{Ne}$, 1.6656 \\ifmmode\\pm\\else\\textpm\\fi{} 0.0019 s, deduced following a 1.4\\ensuremath{\\sigma} correction for detector pulse pile-up, is four times more precise than the previous world average. As part of an investigation into potential systematic effects, the half-life of the heavier isotope $^{23}\\mathrm{Ne}$ was determined to be 37.11 \\ifmmode\\pm\\else\\textpm\\fi{} 0.06 s, a factor of 2 improvement over the previous precision.