The beta-gamma decay of 21Na

A new and independent determination of the Gamow-Teller branching ratio in the beta-decay of 21Na is reported. The value obtained of 5.13 ± 0.43 % is in agreement with the currently adopted value and the most recent measurement. In contrast to previous experiments, the present method was based on the counting of the parent 21Na ions and the resulting 351 keV gamma-rays without coincident beta-particle detection.