EXCLUSIVE AND RESTRICTED-INCLUSIVE REACTIONS INVOLVING THE BE-11 ONE-NEUTRON HALO

Reactions of a 41 MeV/u beam of the radioactive halo nucleus Be-11 hav e been studied with a counter telescope coupled to an array of neutron detectors covering angles up to 97-degrees. The technique allows to d etermine single-neutron inclusive and exclusive angular distributions. The targets (Be, Ti and Au) were chosen to illustrate the relative ro les played by nuclear and Coulomb mechanisms. The channels leading to Be-10, the dissociation channels, correspond to impact parameters larg er than the sum of the radii of the target and the Be-10 core. It is s hown that for the dissociation process it is possible to account almos t quantitatively for the integral, single- and double-differential cro ss sections from models without free parameters including the Coulomb, Serber and Glauber (diffraction-dissociation) mechanisms. The neutron distributions from the nondissociative reaction channels show little individuality and it is convenient to group them together as the chann el ''neutron plus anything different from Be-10''. We refer to these a s ''restricted-inclusive'' reactions. These seem to be a promising too l for obtaining accurate information on the halo wave function in mome ntum coordinates.