The Correction of Specific β-Radioactivity for Self-Absorption

The self-absorption of β-rays in radioactive films between 5 and 100 mg/cm2 superficial density has been investigated. The marked departures from the exponential absorption law are shown to be due to scattering of the β-rays in the film. The use of very thin films to avoid the correction for self-absorption is not recommended as a routine method.