The energy distributions of alpha particles and of protons from the ${\mathrm{He}}^3+t$ reactions have been measured for 1.9-MeV incident tritons at laboratory angles of 30° for alphas, and both 30° and 90° for protons. Absolute cross sections are obtained. The spectra are discussed in terms of a model which assumes that uncorrelated three-body breakup and several two-stage processes all contribute independently to the cross section. The calculations based on this model are in excellent agreement with the observed spectral shapes. The neutron-proton correlation corresponding to the unbound singlet state of the deuteron is observed. The binding energy of ${\mathrm{He}}^5$ (for breakup into a neutron and an alpha particle) was found to be $\epsilon =-0.79\mathrm{}\pm 0.03$ MeV.

• Received 20 August 1962

DOI:https://doi.org/10.1103/PhysRev.129.785