Mass and excited states of ¹²Be

The ¹⁰Be(t,p)¹²Be reaction has been studied with a 94% enriched ¹⁰BeO target, a 17-MeV triton beam, and a multiangle magnetic spectrograph. Proton groups from the (t,p) reaction on ¹²C and ¹⁶O in the target served for energy calibration. An average of data at four angles gives a Q₀ value of -4809 ± 15 keV, from which the mass excess of ¹²Be is calculated to be 25,077.5 ± 15 keV. Excited states of Be12 are found at 2089 ± 20, (2712 ± 20, tentative), 4559 ± 25, and 5703 ± 25 keV. The mass excess of ¹²Be, plus earlier data for A=12, T=2, gives a value of d=+2.8±8.6 keV for the coefficient of the cubic term in the isobaric multiplet mass equation. NUCLEAR STRUCTURE ¹²Be: measured Q values for proton groups in ¹⁰Be(t,p)¹²Be reaction; derived ¹²Be mass excess, E_exc of ¹²Be excited states, IMME coefficients.