Transmutation of Uranium and Thorium by Neutrons

Abstract

IT has been shown by Hahn and Strassmann¹ that uranium bombarded by slow neutrons forms a radioactive noble gas. We repeated their experiments, using the very strong neutron source of the Philips X-Ray Laboratory. About 500 cm.³ of a saturated solution of uranyl nitrate was irradiated. Air was bubbled through the liquid at a rate of 600 cm.³ per minute, then it passed through a tube filled with cotton-wool (length 15 cm.) and through a wash-bottle containing 40 cm.³ of water with a small amount of nitric acid and one drop of ammonia. After adding cæsium, rubidium, barium, strontium and lanthanum salts we obtained from the contents of this wash-bottle radioactive substances which could be precipitated together with cæsium, rubidium and barium.