The mass of ${}^{31}\mathrm{S}$ has been measured with the JYFLTRAP double Penning trap mass spectrometer. The new mass excess value of $-19\hspace{0.5em}042.55(24)\hspace{0.5em}\mathrm{keV}$ deviates from the adopted value of $-19\hspace{0.5em}044.6(15)\hspace{0.5em}\mathrm{keV}$ by $1.4\sigma$. The mass value of ${}^{32}\mathrm{Cl}$ has been revised with the new ${}^{31}\mathrm{S}$ result and the latest data from $\beta$-delayed proton decay of ${}^{32}\mathrm{Cl}$. The new mass excess value for ${}^{32}\mathrm{Cl}$ is $-13\hspace{0.5em}334.88(65)\hspace{0.5em}\mathrm{keV}$, which is the most precise value for ${}^{32}\mathrm{Cl}$ so far and in agreement with the recent (${}^3\mathrm{He},t$) data. The isobaric multiplet mass equation has been tested in the $T=2$ quintet at $A=32$, and the cubic form of the equation has been found to agree with the experimental data. The $Q_{\mathit{EC}}$ value for the $\beta$ decay of $T=1/2$ mirror nucleus ${}^{31}\mathrm{S}$ has been determined as $Q_{\mathit{EC}}=5397.99(24)\hspace{0.5em}\mathrm{keV}$, which slightly deviates from the previously adopted value.

• Received 20 September 2010

DOI:https://doi.org/10.1103/PhysRevC.82.052501