Neutron excess nuclei of hydrogen and helium at ACCULINNA

Abstract

Attempt to observe a 7H resonance produced in the reaction 2H(8He,3He)7H resulted only in setting a limit dσ/dΩ≤ 20 μb/sr for the reaction exit channel which could populate a resonance lying between 0 and 3 MeV above the 7H decay threshold. The quasi-free scattering of the α core bound in 6He was explored keeping in mind the possible study of the cluster structure of this halo nucleus. For the first time coincident particles emitted in the 4He(6He, 2α)nn reaction were detected in wide angular ranges giving a wide kinematical range of the measured angular and momentum distributions. The contribution of processes, competing with QFS in the α+ α+n+n output channel, was considerably suppressed by the selection of events with Eα1(2)-nn>10 MeV. A number of experimental distributions, relevant to the reaction mechanism and to the 6He structure, were compared with the results of MC simulations based on the PWIA formalism. The PWIA predictions showed consistency with the experimental data.