Measurement of the ⁴He(⁶He,⁶He)⁴He cross section with a ⁴He-implanted Al target

In order to obtain information on a possible two-neutron component in the 6He wavefunction, we investigated the 4He(6He, 6He)4He elastic scattering at beam energies of 29.1, 29.6 and 40 MeV and at center-of-mass angles between 20 and 163 degrees. The experiments were performed at the ARENAS3 Radioactive Ion Beam Facility in Louvain-La-Neuve. We used a 4He-implanted aluminium foil as a target. A 4He thickness of about 2'3'1017 particles/cm2 was obtained implanting 4He nuclei at energies between 20 and 80 keV in 0.7-m-thick foils. Data collected in a larger angular range than previous measurements give additional evidence for the 2n-transfer process to take place in the 4He(6He, 6He)4He scattering. Our results demonstrate the possibility of using a 4He-implanted target in experiments with low-intensity beams, like radioactive beams, where deterioration of the target is irrelevant.