The gamma-radiation emitted when lithium is bombarded with protons has been studied by means of a cloud chamber operating in a magnetic field of 2000 gauss. The spectrum consists of at least eleven lines, the highest of which is 16 MEV. The voltage excitation curve for the gamma-radiation shows a maximum at 650 kv proton energy, and is very different from the excitation curve for the 8.4-cm alpha-particles emitted under the same conditions. An attempt is made to interpret these results. The experimental procedure and methods of measuring the cloud chamber tracks are also discussed.

• Received 30 April 1935

DOI:https://doi.org/10.1103/PhysRev.48.125