The New Element Californium (Atomic Number 98)

Abstract

Definite identification has been made of an isotope of the element with atomic number 98 through the irradiation of ${\mathrm{Cm}}^{242}$ with about 35-Mev helium ions in the Berkeley Crocker Laboratory 60-inch cyclotron. The isotope which has been identified has an observed half-life of about 45 min. and is thought to have the mass number 244. The observed mode of decay of ${98}^{244}$ is through the emission of alpha-particles, with energy of about 7.1 Mev, which agrees with predictions. Other considerations involving the systematics of radioactivity in this region indicate that it should also be unstable toward decay by electron capture.