Measurement of spontaneous-fission decay constant of ²³⁸U with a mica solid state track detector

Abstract

The spontaneous-fission decay constant, λ _f , of ²³⁸U is a basic parameter of interest in fields ranging from cosmochronology to reactor physics. Over the years, a number of determinations have been made, yielding a series of values which differ by a factor of two between the extremes, viz. (5.3 ± 0.9) × 10⁻¹⁷ yr⁻¹ found by Perfilov¹ and (11.9 ± 1.0) × 10⁻¹⁷ yr⁻¹ measured by Gerling et al ². It was therefore decided to make a fresh measurement of λ _f using the fission track analysis technique.