Schnelle Abtrennverfahren für Caesium aus Spaltproduktgemischen

Two fast separation methods of caesium from fission products are described which yield rubidium-free samples. In the first method caesium is twice precipitated as tetraphenyloborate from weak acid solution and than purified from rubidium by precipitating caesium bismuth iodide from acetic acid solution. In the second, faster method caesium is isolated by isotopic exchange with preformed caesium phosphomolybdate in 8 N nitric acid and than purified as caesium bismuth iodide. The application of these methods in decay scheme studies of 9.5 min 139Cs, 65 sec 140Cs, 24 sec 141Cs and 18 min 141Ba is briefly discussed.