Radioactivity Induced in Sulphur

Abstract

Under bombardment of 4-6 Mev deuterons, sulphur becomes radioactive with the emission of both positive and negative electrons with 3 periods $3\pm 0.1 m$, $33\pm 1 m$ and $14\pm 0.3 d$. These decay periods were found to have their origin in ${\mathrm{P}}^{30}$, ${\mathrm{Cl}}^{34}$ (both positron emitters) and ${\mathrm{P}}^{32}$ (negative electron emitter). The energy distribution of positrons from Cl was studied by a cloud chamber. When bombarded by neutrons two radioactive substances were produced which emit negative electrons. The half-value periods were found to be $2.6\pm 0.2 h$ and $14 d$, which are characteristic of ${\mathrm{Si}}^{31}$ and ${\mathrm{P}}^{32}$.