Radioactive Scandium. I

Abstract

${\mathrm{Sc}}^{42}$: The existence of this radioactive isotope, reported half-life of 13.4 days, has not been confirmed. ${\mathrm{Sc}}^{43}$: This isotope of 3.92\ifmmode\pm\else\textpm\fi{}0.02 hours half-life has been produced by the reactions $\mathrm{Ca}(d,n)$, $\mathrm{Ca}(\ensuremath{\alpha},p)$ and $\mathrm{Ca}(p,n)$. Positrons of 1.13 Mev and gamma-rays of 1.65 Mev are emitted. The ratio of the number of positrons to gamma-rays is four. ${\mathrm{Sc}}^{44}$: One of the isomers of ${\mathrm{Sc}}^{44}$ decays with a half-life of 3.92\ifmmode\pm\else\textpm\fi{}0.03 hours. The positrons and gamma-rays have the same energy; namely 1.33 Mev. Three gamma-rays per positron are emitted. Absorption measurements in aluminum and in beryllium indicate characteristic x-rays. The other isomer of ${\mathrm{Sc}}^{44}$ has a half-life of 2.44 days. The genetic relation of the isomers of ${\mathrm{Sc}}^{44}$ has been confirmed.