The products of the transmutation of mercury by fast (Li+D) neutrons were investigated. Three radioactive gold isotopes were found to be formed by the n − p reactions: 65-hour Au 198 , 78-hour Au 199 , and a new unassigned electron emitter with a period of 48 min. Three radioactive platinum isotopes were observed and attributed to n − α reactions in mercury: 29-min. Pt 199 , 19-hour Pt 197 , and a new activity with an 80-min. half-life. The latter period was also observed in deuteron and fast neutron bombardment of platinum, but was not found in slow neutron irradiation of platinum. Radioactive mercury isotopes with 43-min., 25-hour, and 50-day periods were observed in the fast neutron irradiation of mercury. The 43-min. and 25-hour activities were also formed by bombarding platinum with α -particles. Difficulties in the assignment of the 80-min. Pt and the 43-min. and 25-hour Hg activities are discussed.

DOI:https://doi.org/10.1103/PhysRev.60.473