The particle decay of the ground state of Be was observed following population in the Li('He, t) Be reaction.The a particle decay spectrum corresponds to the ordinary three body phase space shape for energies above about 100 keV in the 'Be center-of-mass system. At lower energies the relative yield exceeds the available phase space. It is shown that neither the phase space spectrum modified by the proton-proton final state interaction nor the spectrum corresponding to sequential decay through the Li ground state have shapes consistent with the data. The enhanced yield of low energy a particles is not accounted for by either process. RADIOACTIVITY 6Be; measured o (E"). NUCLEAR REACTIONS SBe; 6Li(3He, t)~Be-o.+ 2p, E= 24 MeV measured E&,Ec oin.

No abstract

The properties of high-spin states in ' At have been studied with the ' Pb( Li, 3ny)' At reaction. In-beam measurements with Ge(Li) detectors of y-ray excitation functions, y-y cc incidences, y-ray angular distributions, and pulsed beam-y timing were made to establish decay schemes, level energies, spin-parity assignments, isomeric lifetimes, and magnetic moments. High-spin states involving three valence protons in the 1h9/2 2f7, 2 or 1i)3/ orbitals were identified. The electromagnetic properties observed in ' 'At were compared with those in the closed-neutron core nucleus "'At to examine the influence of the two neutron holes on the proton structure; microscopic calculations of this influence were carried out in perturbation theory.NUCLEAR REACTIONS 6Pb(6Li, any), El, =29-34 KIeV; measured y-excitations, y-y coincidences, y-W(0), pulsed beam-y timing, perturbed angular distributions; deduced level scheme, y multipolarities, J~, T&i&, B(E2), g factor; perturbation calculations.