Mass of ${}^{23}\mathrm{Al}$ for testing the isobaric multiplet mass equation

The mass excess of the proton-rich nucleus ${}^{23}\mathrm{Al}$ has been measured with the JYFLTRAP Penning trap setup. As a result of our experiment we obtain a mass excess of 6748.07(34) keV, and by combining the value to existing experimental data we have tested the validity of the isobaric multiplet mass equation $(\mathrm{IMME})$ for the $T=3/2$ quartet in the $A=23$ isobar. The fit to the IMME results in a vanishing cubic term equivalent to zero with high precision [$0.22(42)$ keV].

Figure 1

Typical cyclotron resonance curves of ${}^{23}\mathrm{Na}$${}^{+}$ (a) and ${}^{23}\mathrm{Al}$${}^{+}$ (b) from this experiment. The RF-excitation time was 100 ms.

Figure 2

Differences between the different measurements and the latest AME value (AME03) [17]. MSU74 refers here to Ref. [19], MSU01 refers to Ref. [20], and JYFL08 is from the work presented in this article. The AME value for ${}^{23}\mathrm{Mg}$ is a combination of two spectrometric studies [40, 41].

Figure 3

The $A=23$, $T=3/2$ multiplet and the fit to the quadratic IMME with $1\sigma$ error bands.

Figure 4

The most recent and precisely determined $d$-coefficients from different isobaric multiplets in the $\mathit{sd}$-shell. The $A=23$ case is from this work, the $A=32$ cases are from Refs. [12, 13], $A=33$ is from Ref. [12], and $A=35$ and $A=36$ are from Ref. [14].