New solution to xenon isotope anomalies

The present composition of atmospheric xenon and xenon in carbonaceous chrondrites and other meteorites is shown here to result from cosmic-ray irradiation on a primitive composition, which gives rise to some mass fractionation and neutron capture effects. With this new theory, a primordial composition line and cosmic composition line is calculated for light isotopes 124Xe and 126Xe. All experimental values essentially lie between these two lines on a three isotope plot. A partition line has been calculated for the heavy isotopes (134Xe and 136Xe), demonstrating the partitioning of the variously sited components. Under these circumstances, it is not necessary to invoke CCFX (carbonaceous chondrite fission xenon) or exotic solar system material to explain the enrichment found in the light and heavy isotopes of xenon. The mass fractionation is seen to be more important in the heavy isotopes, 134Xe and 136Xe, along with some effects from neutron capture processes. The middle isotopes are most sensitive to neutron capture, according to the calculations, and 128Xe is conspicuous for its lack of the 127I(n,γ)128Xe contribution