Mass and excited states ofBe12

The ${}_{}{}^{10}{}_{}{}^{}\mathrm{Be}(t, p){}_{}{}^{12}{}_{}{}^{}\mathrm{Be}$ reaction has been studied with a 94% enriched ${}_{}{}^{10}{}_{}{}^{}\mathrm{Be}$O target, a 17-MeV triton beam, and a multiangle magnetic spectrograph. Proton groups from the ($t, p$) reaction on ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ and ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$ in the target served for energy calibration. An average of data at four angles gives a $Q_0$ value of -4809 ± 15 keV, from which the mass excess of ${}_{}{}^{12}{}_{}{}^{}\mathrm{Be}$ is calculated to be 25,077.5 ± 15 keV. Excited states of ${}_{}{}^{12}{}_{}{}^{}\mathrm{Be}$ are found at 2089 ± 20, (2712 ± 20, tentative), 4559 ± 25, and 5703 ± 25 keV. The mass excess of ${}_{}{}^{12}{}_{}{}^{}\mathrm{Be}$, plus earlier data for $A=12\mathrm{}$, $T=2\mathrm{}$, gives a value of $d=+2.8\mathrm{}\pm 8.6$ keV for the coefficient of the cubic term in the isobaric multiplet mass equation.