High-precision half-life measurement for the superallowed Fermi β+ emitter Mg22

Abstract

A high-precision half-life measurement for the superallowed Fermi β + emitter 22 Mg was performed at the TRIUMF-ISAC facility using a 4π proportional gas counter. The result of T 1/2 = 3.87400 ± 0.00079 s is a factor of 3 more precise than the previously adopted world average and resolves a discrepancy between the two previously published 22 Mg half-life measurements.

The GRIFFIN Facility for Decay-Spectroscopy Studies at TRIUMF-ISAC

“…The system is now fully commissioned and in operation at TRIUMF-ISAC-I. Examples of early measurements performed with the device are halflife measurements of astrophysical interest in the neutron-rich Cd isotopes [65], spectroscopy of 50 Sc related to the rare magnetic octupole transition [66], and in support of a precision half-life measurement of the 22 Mg Fermi superallowed β emitter [67]. The GRIFFIN facility will support a broad spectrum of research in the areas of nuclear structure, nuclear astrophysics and fundamental symmetries.…”