Selective separation of bismuth (212Bi) from a 228Th source

Using alkyl radicals, the nuclides 216Po, 212Pb, 212Bi and 208Tl can be transported from a 228Th source to a detection position. The separation of the alkyl compounds was investigated either using thermal decomposition or a reaction with a gas which yields a non volatile compound. Whereas the thermal decomposition leads only to low enrichment factors, 212Bi was separated selectively by introducing chlorine into the gas phase system. (author)