β decay of ${}^{32}\mathrm{Na}$

The β-decay of ${}^{32}\mathrm{Na}$ has been studied using $\beta \text{−}\gamma$ coincidences. New transitions and levels are tentatively placed in the level scheme of ${}^{32}\mathrm{Mg}$ from an analysis of $\gamma \text{−}\gamma$ and $\beta \text{−}\gamma \text{−}\gamma$ coincidences. The observation of the indirect feeding of the 2321 keV state in ${}^{32}\mathrm{Mg}$ removes some restrictions previously placed on the spin assignment for this state. No evidence of a state at 2117 keV in ${}^{32}\mathrm{Mg}$ is found. Previously unobserved weak transitions up to 5.4 MeV were recorded but could not be placed in the decay scheme of ${}^{32}\mathrm{Na}$.

Figure 1

Gamma spectrum obtained using both tape cycle data sets by requiring $\beta \text{−}\gamma$ coincidences and after bremsstrahlung veto (see text), with known ${}^{30,31,32}\mathrm{Mg}$ lines identified. Transitions identified by ${}^{*}$ are candidates for belonging to the level schemes of ${}^{30,31,32}\mathrm{Mg}$. (see table )

Figure 2

Projections of $\gamma \text{−}\gamma$ (light) and $\beta \text{−}\gamma \text{−}\gamma$ (dark) coincidence data sets for selected runs.

Figure 3

Coincidence spectra using both tape cycle data sets supporting the evidence of a new state at 3553 keV and possibly another one at 4785 keV in ${}^{32}\mathrm{Mg}$. The total number of events in each coincidence spectrum is indicated in the title together with the transition around which the gate was placed. Spectra labeled (a),(c) and (d) are obtained in $\beta \text{−}\gamma \text{−}\gamma$ coincidences, while spectrum (b) is obtained using $\gamma \text{−}\gamma$ coincidences only (see text).

Figure 4

Decay scheme in ${}^{32}\mathrm{Mg}$ as observed in this work. The dashed lines indicate the new transitions and levels. Energies are in keV.