Deuteron Disintegration by Au, Rh, Cu, and C from 8 to 15 MeV

Deuteron disintegration by Au, Rh, Cu, and C has been studied with a $p-n$ correlation technique. In all targets, the neutrons tend to go predominantly in the forward direction. For heavier targets and lower deuteron energies, the protons are emitted predominantly on the same side of the beam as the neutrons and at larger angles (although there is a small secondary peak on the opposite side of the beam), while for lighter targets and higher deuteron energies, they are emitted predominantly on the opposite side of the beam from the neutrons. From this it is surmised that the former behavior characterizes a breakup by the Coulomb force, while the latter behavior characterizes a breakup by the nuclear force; this conclusion is supported by theoretical estimates. From the energy sharing between neutrons and protons, the average radius at which breakup occurs is determined; as expected, it is much larger for Coulomb than for nuclear breakup, but in all cases it is more than twice as large as the usual "nuclear radius."