An Attempt to Accelerate the Rate of Radioactive Transformation

Abstract

DANYSZ and Wertonstein showed in 1915 (Comptes rendus, 161, 784; 1915) that when uranium oxide is bombarded by the α-rays of radium, not one in five million α-particles is effective in changing an atom of U into an atom of UX₁. If we consider that with a layer of uranium containing 1 mgm. per cm.² one α-particle in 20,000 penetrates to a distance less than 5 x 10^-12 cm. from the nucleus, and that the emission of an α-particle from uranium seems to start at a distance greater than 5 × 10^-12 cm., it is surprising that the unstable radioactive atom shows itself so stable.