Radiochemical Studies on the Isotope Plutonium-241,

A large number of plutonium isotopes have been prepared and studied during the course of the Manhattan project and subsequent operations. Plutonium isotopes from mass 232 to 243 have been characterized and their radiations measured. Of these isotopes, the group of mass 238 to 242 are of particular importance due to their production in appreciable quantities by neutron irradiation of uranium in chain-reacting piles. The investigation of plutonium-238, -239, and -240 has been intensively pursued, however relatively little work has been reported on plutonium-24l. Since this isotope is the third most abundant in pile produced plutonium, its study with regard to its production and radioactive characteristics is highly desirable. A knowledge of the isotopic composition of pile produced plutonium is of importance to pile operation, the determination of the specific activity of pile produced plutonium, and the determination of effective pile cross sections. Furthermore, since the isotopes of americium and curium grow into irradiated uranium through the decay of plutonium 241, the abundance of the heavy transuranics may be predicted from plutonium 241 contents and a knowledge of the half life. In connnection with a program involving isotopic abundances and analysis, the present investigation was initiated to obtain analytical methods for the determination of plutonium 241 and to determine its occurrence in plutonium produced in the Hanford Piles.