A Differential Counter for the Determination of Small Differences in Decay Rates

Abstract
An instrument for the determination of small changes in the rate of decay of a radioisotope has been constructed. It operates on the principle of differential comparison of the unkown decay rate with that of a known, usually practically nondecaying (e.g., 36Cl) reference. The apparatus can be used both for the determination of long half‐lives, and for studying the effect of chemical state upon the half‐life of a radioisotope.