Improved half-life determination and β -delayed γ -ray spectroscopy for 18 Ne decay

The half-life of the superallowed Fermi beta(+) emitter Ne-18 has been determined to +/- 0.07% precision by counting 1042 keV delayed gamma rays that follow approximately 8% of all beta decays. The deduced half-life, T-1/2 = 1.6648 (11) s, includes a 0.7% correction that accounts for systematic losses associated with rate-dependent detector pulse pileup that was determined using a recently developed gamma-ray photopeak-counting technique. This result is a factor of two times more precise than, and in excellent agreement with, a previous lower-statistics measurement that employed the same experimental setup. High-resolution beta-delayed gamma-ray spectroscopy results for the relative gamma-ray intensities and beta-decay branching ratios to excited states in the daughter F-18 are also presented. DOI: 10.1103/PhysRevC.87.045502