RADIOACTIVE ISOTOPES OF RHENIUM AND OSMIUM FORMED BY THE BOMBARDMENT OF RHENIUM WITH PROTONS

Abstract

Targets of normal rhenium, and of rhenium enriched in each stable isotope, were bombarded by protons in the energy range 10 to 80 Mev. These produced osmium and rhenium isotopes of masses 185, 183, 182, 181, and 180. After chemical separations, the gamma rays and conversion electrons were examined for half-lives, and to determine certain conversion coefficients. Independent isomers of Os183 with 10 and 15.4 hour half-lives were found. Gamma rays with energies 168.1, 850, and 1097 kev. were assigned to the 10 hour isomer, and gamma rays with energies 114.6, 168.7, and 382.4 kev. were assigned to the 15.4 hour isomer. In addition, the half-lives of Os185, Os182, and Re183 were observed to be 93.4 days, 21.9 hours, and 67.6 days respectively. Activities with half-lives of 19 hours, 23 minutes, 18 minutes, and 2 minutes were tentatively assigned to Re181, Os181, Re180, and Os180 respectively.