(See the Isobar Diagram for 12Be)
General review: (1974CE1A).
Mass of 12Be: The Q-value of the 14C(18O, 20Ne)12Be reaction [-15.77 ± 0.05 MeV] (1974BA15) leads to an atomic mass excess of 25.05 ± 0.05 MeV; that for the 7Li(7Li, 2p)12Be reaction [Q = -9.71 ± 0.10 MeV] (1971HO26) leads to an A.M.E. of 24.95 ± 0.10 MeV. We adopt an atomic mass excess of 25.030 ± 0.045 MeV for 12Be. The binding energies of (11Be + n), (10Be + 2n) and (9Be + 3n) are then 3.22, 3.72 and 10.53 MeV, respectively. See also (1972CE1A, 1972WA07, 1974TH01).
An activity of τ1/2 = 11.4 ± 0.5 msec, observed in the GeV proton bombardment of various targets, is ascribed to 12Be. log ft = 3.5 if the transition is to the ground state of 12B (1965PO03).
This reaction has been studied at E(7Li) = 25.0, 30.0 and 30.1 MeV. The ground state of 12Be and an excited state with Ex = 0.81 ± 0.10 MeV are populated with cross sections of 2.9 ± 1.0 μb/sr2 and 1.1 ± 0.6 μb/sr2, respectively (1971HO26, 1971HO1J).
At E(18O) = 88.7 MeV, the population of the ground state of 12Be and of an excited state at Ex = 2.09 ± 0.05 MeV [and of many states in 20Ne: see (1978AJ03)] is reported by (1974BA15). 12Be*(0.81), reported in reaction 2, was not observed by (1974BA15).