A Photographic Plate Spectrum of the Neutrons from the Disintegration of Lithium by Deuterons

The energy spectrum of the neutrons from Li+${\mathrm{H}}^2$ has been studied by the photographic emulsion technique. Confirmation is given of the broad 10.8-Mev neutron group reported by Stephens from He recoil data. Reasons are given for believing that not all the neutrons from this group correspond to the 2.8-Mev excitation level in the residual ${\mathrm{Be}}^8$ nucleus. Evidence is also given for at least two higher (7.5 Mev and 10 Mev) levels in ${\mathrm{Be}}^8$. A discussion of the photographic emulsion technique is included, and a correction is calculated for the differing probability that long tracks be acceptable for measurement. The stopping power of the emulsion for three different proton energies was found.