Variation of the isotopic composition of xenon in the solar system

Re-examination of a vast amount of existing xenon isotope data. which have been accumulated in the literature since the 1960's. reveals that the variation of the isotopic composition of xenon in the solar system can be attributed to a combined effect of(a) mass-fractionation, (b) spallation and (c) stellar-temperature neutron-capture reactions plus the addition uf (d) the beta-decay product of I-129 and of (e) the spontaneous fission products of Pu-244. The effect of each of the above-mentioned processes can be extremely large, due, primarily to the fact that these processes occurred in the interior of a supernova. which exploded about 5.1 billion years ago.