Formation of 236Pu, 237Pu, and 238Pu isotopes by 3He-induced nuclear reactions on uranium

The reaction U(3He,xn)Pu was studied by irradiating enriched 235U (50.3%) and enriched 238U (99.7%) targets with 3He ions at the Abo Akademi cyclotron (Turku, Finland). The incident 3He ion energy in the irradiations was 27.0, 24.5 and 21.9 MeV. Plutonium was separated from the thin uranium targets by ion exchange. From the ion exchange fractions obtained, plutonium was electrodeposited on steel plates for alpha and X-ray counting. The activity of 237Pu in the steel plates was determined with a Ge(Li) detector and the activity of 236Pu and 238Pu with a Si surface barrier detector. The cross sections of the reactions and the yields of plutonium isotopes are given. (author)