27Al(n,a )24Na
The 27Al(n,a )24Na reaction and decay scheme are shown below. The 24Na beta decay feeds into the second excited state of 24Mg 99.944% of the time. The transition from the second to the first excited state of 24Mg emits a 2.754 MeV gamma ray 99.944% of the time. Subsequently, the first excited state de-excites 100% of the time to the ground state, emitting a 1.368 MeV gamma ray making this transition a good indicator of the measure of activation of the aluminum sample.
