Neutrons from Lithium Plus Deuterons

The energy distribution of the neutrons from the disintegration of lithium by deuterons has been measured by the method of $\alpha$-recoils in a helium-filled high pressure cloud chamber. The stopping power was calibrated with thorium C′ $\alpha$-particles in the chamber. Two distinct groups of neutrons were found with disintegration energies of 15.05±0.2 Mev and 11.8±0.4 Mev. The 15.05 Mev group is attributed to the formation of ${\mathrm{Be}}^8$ in a normal state and the 11.8 Mev group to the formation of ${\mathrm{Be}}^8$ in an excited state of about 3.3 Mev with a width at half-maximum of about 1.5 Mev. A more or less continuous distribution was observed from 9 Mev to 3 Mev (the limit of observation). These neutrons may come from higher wider states of ${\mathrm{Be}}^8$.