The energy spectra of tritons and Helium-3 nuclei from the reactions 3He(d,t)2p, 3H(d,3He)2n, 3He(d,3He)pn, and 3H(d,t)pn were measured between 6° and 20° at a bombarding energy of 10.9 MeV. An upper limit of 5 μb/sr. was obtained for producing a bound di-neutron at 6° and 7.5°. The 3He(d,t)2p and 3H(d,3He)2n data, together with previous measurements at higher energies, have been used to investigate whether one can unambiguously extract information on the two-nucleon system from these three-body final state reactions. As an aid to these theoretical investigations, Born approximation calculations were made employing realistic nucleon-nucleon potentials and an antisymmetrized final state wave function for the five-particle system. These calculations reproduce many of the features observed in the experimental data and indicate that the role of exchange processes cannot be ignored. The results show that previous attempts to obtain information on the neutron-neutron scattering length from the 3H(d,3He)2n reaction may have seriously overestimated the precision that could be attained.
