Figure 1

Layout of the MISTRAL spectrometer (overhead view). The ion beams (coming from the bottom) are injected either from the ISOLDE beam line (at 60 keV) or from a reference ion source (variable energy). The inset (bottom) shows an isometric view of the trajectory envelope with the 0.4 mm injection slit followed by the first modulator at one-half turn, an opening to accommodate the modulated-ion trajectories at one turn, the second modulator at three-half turns, and then the exit slit. The inset (left) shows the transmitted-ion signal over two harmonics for a reference ion.Reuse & Permissions

Figure 2

(Top) Time profile of the transmitted ${}^{11}\mathrm{Li}$ ions that shows the release curve of ${}^{11}\mathrm{Li}$ from the Ta-foil target, dominated by the 8.6-ms half-life. An exponential fit yields a half-life of $10\pm 2\mathrm{ms}$, strong confirmation that the measured peak is indeed that of ${}^{11}\mathrm{Li}$. (Bottom) Transmitted ${}^{11}\mathrm{Li}$ ions plotted versus modulation frequency and fit with the theoretically expected line shape [25]. Resolving power is 57 170.Reuse & Permissions

Figure 3

Individual corrected measurements of the ${}^{11}\mathrm{B}–{}^{11}\mathrm{Li}$ doublet, including all sources of error. Also shown is the error band of the weighted average.Reuse & Permissions

Figure 4

${}^{11}\mathrm{Li}$ two-neutron separation energies derived from various mass measurements: CERN [30]; TOFI [31]; KEK [32]; MSU [33]; MISTRAL [this work]. The error band is the AME [27].Reuse & Permissions