Radioactivity ofBe10

From the beta-activity induced in beryllium by (1) fast deuteron bombardment, and (2) slow neutron capture, the half-life of ${\mathrm{Be}}^{10}$ is determined. The value is between ${10}^6$ and ${10}^7$ years. The beta-end-point is roughly 650 kev, and no gammas were observed. These results confirm those of McMillan and Ruben. The ${\mathrm{B}}^{10}\mathrm{}(n,p)\mathrm{}{\mathrm{Be}}^{10}$ cross section for thermal neutrons is computed by comparison with the known value for ${\mathrm{B}}^{10}(n,\alpha ){\mathrm{Li}}^7$, assuming disintegration to the ground state possible for the former reaction.