New Nuclide, Krypton-74

A new nuclide of krypton, ${\mathrm{Kr}}^{74}$, has been produced by high-energy proton interaction with strontium. It was found to have a half-life of (20±1) minutes and to decay by (3.1±0.1)-Mev positrons. No gamma rays in the energy range 0.04 to 4.0 Mev were observed. Evidence for the production of ${\mathrm{Kr}}^{75}$ was also observed. Calculations indicate an upper limit for the half-life of (0.8±0.4) minutes.