MOMENTUM DISTRIBUTIONS FOR BE-12, BE-14 FRAGMENTATION

Data on the fragmentation of Be-12, Be-14, on C-12 at 56 and 65 MeV pe r nucleon have been obtained. The Be-12 fragments from the breakup of Be-14 display both a narrow longitudinal momentum distribution and a d istinctive angular distribution that is consistent with an extended ne utron ''halo'' in this nucleus. This is the first experiment in which both longitudinal and transverse fragment momentum, of exotic nuclei h ave been simultaneously measured.