Protons from the Transmutation of Boron by Deuterons

The technique of studying proton groups produced by bombarding elements with deuterons from a cyclotron is described. Applied to the bombardment of boron by 3.1-Mev deuterons, the method shows the presence of four groups, three of which agree with those found by Cockcroft and Lewis while the fourth, a very prominent group of Q value +2.39 Mev is new and is ascribed to a third excited state of B¹¹.