The energy and angular distributions of He-3 and He-4 ions produced in
the Be-7 + Ni-58 reaction at a bombarding energy of 22 MeV have been
measured for the first time. The yield of the heavier helium isotope was
four to five times more abundant than that of its lighter counterpart,
ruling out the possibility that in this energy range the Be-7 reaction
dynamics is dominated by the exclusive breakup process Be-7 -> He-3 +
He-4 (S-alpha = 1.586 MeV). Extensive kinematic and theoretical
calculations suggest that the He-3 ions mostly originate from the
He-4-stripping process and the He-4 production is mainly triggered by
the fusion-evaporation channel. The role played by the breakup,
He-3-stripping, 1n-stripping, and 1n-pickup processes is also discussed