GB642072A - Improvements in radioactive metallic foil products - Google Patents

Abstract

<PICT:0642072/III/1> <PICT:0642072/III/2> An alpha particle-emitting radioactive foil comprises a thin metallic core preferably of gold containing a dispersed radioactive substance such as radium sulphate, a thin continuous non-radioactive metallic film, preferably gold surrounding both sides of the core, and a further thin metallic film applied over the first film and core, preferably after the product has been cut to the desired size. Escape of radium emanation gas is thereby prevented or reduced. The combined thickness of the two sealing films should not be greater than that which can be penetrated by alpha particles emitted from the core with maximum energy. According to a preferred embodiment the outer film 7 (Fig. 1), is of nickel or chromium electrodeposited to cover the cut edges of the core and inner film as at 8, and may be secured to a backing 9 of metal or glass, or may completely surround the backing 19 of Fig. 2 already secured to inner film 16. The core and inner film are preferably prepared according to Specification 636,338.