Curium-248 in the early solar system

Abstract

Primitive meteorites such as carbonaceous chondrites (CC) and unequilibrated ordinary chondrites (UOC) have an anomalous fission xenon component which has a distinctly different fission spectrum from that of Ca-rich achondrites. Although the latter is established as due to ²⁴⁴Pu spontaneous fission, the origin of the former component is still debated. Further, the amount of fission xenon present in CC II-IV and some UOC is about two orders of magnitude higher than that of Ca-rich achondrites and even the maximum value of ²⁴⁴Pu could account only for 10% of CC fission xenon. Several mechanisms, such as carrier hypothesis, mass fractionation, superheavy elements, and two-component trapped xenon, have been proposed to explain the CC fission xenon. Here we attempt to determine whether some actinide isotopes with known properties could produce this excess fission xenon in the primitive chondrites.