Coincidence Measurements. Part I. Beta Spectra

Abstract

The necessary and sufficient conditions for a simple $\beta$ spectrum (not accompanied by internally converted $\gamma$ radiation) are discussed. It is generally considered that the $\beta -\gamma$ coincidence rate per recorded $\beta$ particle decreases with an increase of absorber thickness for a complex $\beta$ spectrum. Although this is the most common condition, it is possible for the ratio to remain constant or even rise as the $\beta$ absorber thickness is increased.