High precision measurements ofNa26β−decay

Abstract

High-precision measurements of the half-life and \ensuremath{\beta}-branching ratios for the ${\ensuremath{\beta}}^{\ensuremath{-}}$ decay of $^{26}\mathrm{Na}$ to $^{26}\mathrm{Mg}$ have been measured in \ensuremath{\beta}-counting and \ensuremath{\gamma}-decay experiments, respectively. A 4\ensuremath{\pi} proportional counter and fast tape transport system were employed for the half-life measurement, whereas the \ensuremath{\gamma} rays emitted by the daughter nucleus $^{26}\mathrm{Mg}$ were detected with the $8\ensuremath{\pi}$ \ensuremath{\gamma}-ray spectrometer, both located at TRIUMF's isotope separator and accelerator radioactive beam facility. The half-life of $^{26}\mathrm{Na}$ was determined to be ${T}_{1/2}=1.07128\ifmmode\pm\else\textpm\fi{}0.00013\ifmmode\pm\else\textpm\fi{}0.00021\phantom{\rule{0.3em}{0ex}}\text{s}$, where the first error is statistical and the second systematic. The logft values derived from these experiments are compared with theoretical values from a full sd-shell model calculation.