Long-range Particles from Radium-active Deposit

Abstract

WHILE studying the H-particles found by Sir Ernest Rutherford to be the first disintegration product of aluminium and some other atoms, under α-bombardment, we have developed a new method for obtaining strong and practically constant sources of such radiation. The method consists in enclosing dry radium emanation mixed with pure oxygen within thin-walled capillaries of hard (potassium) glass, lined with some 12 µ thickness of aluminium foil pressing well against the glass. As a small number of long-range particles were given off from the glass itself, we have also made use of capillaries drawn out from tubes of pure silica.