Detection of Nuclear Disintegration in a Photographic Emulsion

IT has been shown recently by Chadwick and Goldhaber¹, and by Fermi and his collaborators², that some light nuclei, particularly lithium and boron, are disintegrated by slow neutrons. In the case of boron, the mass-energy relations seemed best satisfied by assuming a disintegration into three particles¹. The simplest reaction, namely: should, according to the accepted masses of the particles, release some two million e. volts more energy than is observed. Unless the existence of new isotopes, He⁵ or Li⁸, of improbably low masses, be assumed, no other disintegration into two particles would fit the mass-energy relations.