The reaction U(3He, xn)Pu was studied by irradiating enriched235U (50.3%) and enriched238U (99.7%) targets with3He ions at the Åbo Akademi cyclotron (Turku, Finland). The incident3He 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 of237Pu in the steel plates was determined with a Ge(Li) detector and the activity of236Pu and238Pu with a Si surface barrier detector. The cross sections of the reactions and the yields of plutonium isotopes are given.