III. Investigation of soft radiations—<i>II</i>. The beta spectrum of tritium

Abstract

Summary The β-spectrum of tritium is investigated between 0·5 kev. and the upper energy limit, 17·9 kev. Detailed results near the low energy end and close to the upper limit are presented. The spectrum is shown to be simple and in reasonable agreement with Fermi theory. There is evidence of some deficiency in β-rays of low energy. The best fit with theory is obtained for a neutrino mass μ=m/500 (m=electron rest mass).