Radioactive Isotopes of Sr, Y and Zr

Abstract

Radioactive isotopes formed by bombardment of Rb, Sr and Y by protons, deuterons and neutrons are reported. The following are the periods and assignments: 2.75-hr. (${\mathrm{Sr}}^{87*}$, ${e}^{\ensuremath{-}}$, $\ensuremath{\gamma}$); 70-min. (${\mathrm{Sr}}^{85}$, ${e}^{\ensuremath{-}}$, $\ensuremath{\gamma}$); 66-day (${\mathrm{Sr}}^{85}$, $\mathrm{K}$, $\ensuremath{\gamma}$); 80-hr. (${\mathrm{Y}}^{87}$, K); 14-hr. (${\mathrm{Y}}^{87}$, ${e}^{\ensuremath{-}}$, $\ensuremath{\gamma}$); 105-day (${\mathrm{Y}}^{86}$, $\mathrm{K}$, $\ensuremath{\gamma}$); 4.5-min. (${\mathrm{Zr}}^{89}$, $\ensuremath{\gamma}$); 78-hr. (${\mathrm{Zr}}^{89}$, ${\ensuremath{\beta}}^{+}$). (In each case ${e}^{\ensuremath{-}}$ means conversion electrons, not nuclear $\ensuremath{\beta}$-rays.) The electron spectrum of the 2.75-hr. ${\mathrm{Sr}}^{87*}$ shows a single line at 360 kev and this period is shown to grow from the 80-hr. ${\mathrm{Y}}^{87}$, but not from the 14-hr. isomer.