PU-244 AND STRANGE XENON COMPONENTS IN THE SOLAR-SYSTEM

A number of strange xenon components have been reported in the literat ure during the past three decades; for example, AVCC (average carbonac eous chondrite), CCF (carbonaceous chondrite fission) xenon, xenon-X x enon-H, xenon-L, xenon-S, xenon-U, SUCOR (surface correlated xenon), B EOC (Bern Oberflachen-Correliert) xenon, and so on. It is often assume d that they represent the isotopic compositions of more or less 'pure' or 'primordial' components of xenon. If one attempts to interpret the existing xenon isotope data for meteorites and lunar samples, assumin g that they are 'pure' or 'primordial', however, one encounters all so rts of problems and no coherent theory concerning the variation of the isotopic composition of xenon in the solar system emerges. We have th erefore re-examined over 4,000 sets of existing xenon isotope data for meteorites and lunar samples. The results indicate that these strange xenon components are mixtures of Pu-244 fission xenon and atmospheric xenon, whose isotopic compositions have been altered by the processes of a) mass-fractionation, b) spallation and c) neutron-capture reacti ons.