A Re-Investigation of the Double Beta-Decay fromSn124

Abstract

Radiations from natural tin and tin enriched with the 124 isotope are examined in a magnetic field with a helium filled cloud chamber that is triggered by internal counters. Only three pictures out of more than four thousand photographs are pictures of two electrons coming out of the same point in the tin and entering the counters, and even these may be pictures of multiply scattered electrons passing through the tin. However, one may set a lower limit to the half-life of double beta-decay from ${\mathrm{Sn}}^{124}$ as ${10}^{17}$ years. This is a decay rate less than one-tenth of a value previously reported by one of the authors.