Beiträge zur Umweltforschung und Umweltüberwachung II: Präparative Darstellung von $^{237}$Pu und orientierende Vorversuche zur Bioakkumulation in Süßalgen und Seewasseralgen

Abstract

The ${237}$Pu-production is performed by irradiation of an $^{235}$U target (93 % $^{235}$U) with $\alpha$-particles in an Isochroncyclotron (optimal energy 70 MeV). The design of the used targets, their performance under the applied irradiation conditions together with the dissolution and the radiochemical separation andpurification steps is described. Preliminary bioaccumulation experiments with algae (Chlorella n inland water, Dunlaiella in sea water) are outlined. The enrichment factor for Chlorella was under favourable conditions around 6600, for Dunlaiella around 3000. Recovery of $^{237}$Pu from biological material and aqueous solutions is possible with about 90 % yield