Studies of the Short-Lived ActivitiesC15,F17,O19,F20, andAl28

Abstract

The short-lived activities ${\mathrm{C}}^{15}$, ${\mathrm{F}}^{17}$, ${\mathrm{O}}^{19}$, ${\mathrm{F}}^{20}$, and ${\mathrm{Al}}^{28}$ have been studied by bombarding targets with a mechanically chopped Van de Graaff deuteron beam and by measuring the delayed gamma radiations with a lithium-drifted germanium detector. In the decay of ${\mathrm{C}}^{15}$, weak gamma rays of 8315±6 and 9048±4 keV have been observed which correspond to beta-ray branches to the 8312- and 9052-keV states of ${\mathrm{N}}^{15}$ with $log\mathrm{ft}$ values of 4.8±0.3 and 3.7±0.3, respectively. In the known beta decay of ${\mathrm{O}}^{19}$ to the 1554-keV level of ${\mathrm{F}}^{19}$, the energy of this state is found to be 1553.9±1.3 keV, and the measured gamma-ray branching intensities agree with previous results. A weak gamma ray of 3334±8 keV was observed in the beta decay of ${\mathrm{F}}^{20}$, corresponding to a beta-ray branch to the 4969-keV state of ${\mathrm{Ne}}^{20}$ with $logft=6.9\mathrm{}\pm 0.2$. The energy of the ${\mathrm{Ne}}^{20}$ first excited state was measured as 1632.6±0.8 keV. The gamma ray emitted in the decay of ${\mathrm{Al}}^{28}$ has an energy of 1777.8±0.6 keV. Upper limits are given for other possible beta-ray branches to known states in the decays of the various activities studied.