Dosimetry method for β radiation based on investigations of the electron spectra in the fields of β emitters

Abstract

A method has been developed for β-ray dosimetry based on the investigation of the effective electron spectra in the fields of β emitters. The β spectra was investigated with the help of a scintillation spectrometer. It was shown, that the value of the dose$D = N\left( {\frac{{\overline {dE} }}{{dx}}} \right)$, where N is the number of β particles penetrating an infinitesimal volume around the point being considered;$\left( {\frac{{\overline {dE} }}{{dx}}} \right)$ is the value of the ionization loss averaged over the spectrum. It was established that the quantity$\left( {\frac{{dE}}{{dx}}} \right)$ is determined by the maximum energy of the β spectrum of the isotope and may be considered to be independent of the depth of the medium and of the source diameter. Curves of depth doses for S³⁵, Tl²⁰⁴, Y⁹¹, and Ce¹⁴⁴ + Pr¹⁴⁴ are given and criteria for selecting isotopes to provide optimal conditions of irradiation are established.