The Radionuclides of Arsenic Produced by Deuteron Bombardment of Germanium

Abstract

The arsenic produced by a deuteron bombardment of germanium has been studied to determine the nuclides present in the mixture. Identification of the isotopes was made by comparing measured values of half-life and maximum $\ensuremath{\beta}$ energy with published values. Counting rates were measured with $4\ensuremath{\pi}$ and coincidence counters, obtaining half-lives which indicated that the nuclidic mixture was made up of ${\mathrm{As}}^{71}$, ${\mathrm{As}}^{72}$, ${\mathrm{As}}^{73}$, ${\mathrm{As}}^{74}$, and ${\mathrm{As}}^{77}$. These findings were confirmed by maximum $\ensuremath{\beta}$ energy values obtained by absorption measurements and by $\ensuremath{\gamma}$-energy values found using a $\ensuremath{\gamma}$-ray scintillation spectrometer. Measurements indicated that the 40-hr half-life reported for ${\mathrm{As}}^{77}$ is in error by a significant amount, and that no ${\mathrm{As}}^{76}$ was obtained from this bombardment. Thick target yield data were determined for each nuclide from the $4\ensuremath{\pi}$ counter measurements.