XXXII. The low energy beta-ray spectrum of¹⁷⁰Tm

Abstract

Abstract A thin magnetic lens beta-ray spectrometer in conjunction with a coincidence circuit employing a pair of photo-multipliers has been used to examine the low energy beta-ray spectrum of 170Tm, which was expected to exhibit a forbidden shape. The spectrum was, however, found to have an allowed shape. The results may best be interpreted on the assumption that the transition is first forbidden with axial vector or tensor interaction, the latter interaction being slightly favoured.