Experiments with high velocity positive ions. II. -The disintegration of elements by high velocity protons

Abstract

In a previous paper we have described a method of producing high velocity positive ions having energies up to 700,000 electron volts. We first used this method to determine the range of high-speed protons in air and hydrogen and the results obtained will be described in a subsequent paper. In the present communication we describe experiments which show that protons having energies above 150,000 volts are capable of disintegrating a considerable number of elements. Experiments in artificial disintegration have in the past been carried out with streams of α -particles as the bombarding particles; the resulting transmutations have in general been accompanied by the emission of a proton and in some cases γ -radiation. The present experiments show that under the bombardment of protons, α -particles are emitted from many elements; the disintegration process is thus in a sense the reverse process to the α -particle transformation.