Angular Distribution of the ${\mathrm{Al}}^{27}(d,\alpha ){\mathrm{Mg}}^{25}$ Reaction and Energy Levels in ${\mathrm{Mg}}^{25}$

The energy distribution and angular dependence of the alpha-particle groups from the nuclear reaction ${\mathrm{Al}}^{27}(d,\alpha ){\mathrm{Mg}}^{25}$ have been investigated. A magnetically analyzed beam of 11.1 Mev deuterons was used. Eleven alpha-particle groups were measured, corresponding to ten excited levels in ${\mathrm{Mg}}^{25}$ at 0.57, 0.96, 1.63, 1.97, 2.74, 3.36, 4.01, 4.81, 5.48, and 5.95 Mev. The ground state $Q$-value for the reaction was found to be 6.58±0.03 Mev, giving a value for the mass difference ${\mathrm{Al}}^{27}$-${\mathrm{Mg}}^{25}$ of 1.99626±0.00003 mass units. The intensities of all the groups, with the exception of $Q_2$, show marked dependence on the angle of measurement. The average spacing of the levels in ${\mathrm{Mg}}^{25}$ is 0.6 Mev, and is nearly constant over the range studied.