The Radioactivity ofSe73

Abstract

The disintegration of ${\mathrm{Se}}^{73}$ results in four positron groups with end-point energies and relative intensities of 1.68 Mev, 1.2 percent; 1.318 Mev, 87.4 percent; 0.750 Mev, 10.3 percent; and 0.250 Mev, 1.1 percent. Four nuclear gamma-rays are observed having energies of 67.1 kev, 361 kev, 860 kev, and 1.31 Mev. The $\frac{K}{L}$ ratio of the internally converted electrons from the 67.1-kev and 361-kev gamma-ray transitions are 7.6 and 8.6, respectively. $K$-capture—positron branching ratios are measured as 0.45 for the 1.318-Mev positron transitions, 1.6 for the 0.750-Mev positron transition and estimated as 6 for the 0.250-Mev positron transition. Measurement of the $K$-Auger electrons indicates a gross $K$-capture—positron ratio of 0.59.