An independent measurement of the 12C(α, γ)16O cross section with the Karlsruhe 4π BaF2 detector

An independent approach for the measurement of the 12C(α, γ)16O cross section at low energies has been performed at Forschungszentrum Karlsruhe using the 4π BaF2 detector and the pulsed 3.7 MV Van de Graaff accelerator. Covering the full solid angle, the Karlsruhe 4π BaF2 detector combines high gamma-ray efficiency with a 42-fold segmentation. This allows one to measure the total 12C(α, γ)16O cross section and the angular distribution simultaneously. The Van de Graaff accelerator was operated in pulsed mode in order to discriminate neutron background from the 13C(α,n)16O reaction. With a pulse width below 2 ns and beam currents of up to 6 μA, the cross section could be measured at center of mass energies between 1.0 and 1.51 MeV yielding angular distributions with up to 12 angles.