Delayed particles from the beta decay of Be-11

Jan, 1981
6 pages
Published in:
  • Phys.Rev.C 23 (1981) 473-479

Citations per year

19821993200420152024102
Abstract: (APS)
Heavy particles emitted in the β decay of Be11 were studied by forming the activity in the Be9(t,p)Be11 reaction at Et=3.4 MeV and measuring the radiations by means of a helium-jet system together with Si and NaI(Tl) detectors. α particles and corresponding Li7 recoil ions were observed both in singles and in coincidence with 478-keV γ rays. It is deduced that Be11 branches 2.9±0.4% by β-ray emission to the 9875-keV Jπ=32+ excited state of B11, which then decays by α emission 87.4±1.2% to the ground state of Li7 and 12.6±1.2% to the 478-keV excited state. The experimental logft of 4.04±0.08 for the Be11 β branch to the 9875-keV state agrees with a theoretical estimate of ≃4.0, and the ambiguity in an earlier result is thereby resolved. The α branching intensity to the Li7 478-keV state is in reasonable agreement with a theoretical estimate. [RADIOACTIVITY Be11; measured delayed α, Li7, and α−γ coin; He-jet system, Si and NaI(Tl) detectors; deduced β and α decay branches; compared with theory.]