The Disintegration of Beryllium and the Masses of the Beryllium Isotopes

The following disintegrations have been studied up to bombarding energies of 250 Kv. $\{{\mathrm{Be}}^9+{\mathrm{H}}^1\to \left(\{{\mathrm{Be}}^8+{\mathrm{H}}^2\}\{{\mathrm{Li}}^6+{\mathrm{He}}^4\}\right),\}\{{\mathrm{Be}}^9+{\mathrm{H}}^2\to {\mathrm{Li}}^7+{\mathrm{He}}^4+Q_2,\}\{{\mathrm{Be}}^9+{\mathrm{H}}^2\to {\mathrm{Be}}^8+{\mathrm{H}}^3+Q_3,\}\{{\mathrm{Be}}^9+{\mathrm{H}}^2\to {\mathrm{Be}}^{10}+{\mathrm{H}}^1+Q_4.\}$ Efficiency curves for the four reactions are smooth and regular. Absolute yields from a thick target are given. Range measurements of the disintegration products determine the values of $Q_2$, $Q_3$, $Q_4$ as 6.95, 4.32, and 4.44 Mev respectively and the masses of ${\mathrm{Be}}^8$, ${\mathrm{Be}}^9$, ${\mathrm{Be}}^{10}$ as 8.0081, 9.0150 and 10.0168.