Eu isotope measurements on single SiC grains from the Murchison meteorite: A new probe of s-process conditions in parent Asymptotic Giant Branch stars

Abstract

Europium isotopic composition could be a good probe to investigate the neutron capture process in Asymptotic Giant Branch stars (AGB stars) and/or supernovae, because the 151Sm and 153Sm branchings are sensitive to the neutron densities and temperature. Here, we report Eu isotopic analyses of single SiC grains from primitive meteorites using the sensitive high resolution ion microprobe (SHRIMP). The results are compared with Eu isotopic ratios predicted from the recently determined 151Sm(n,γ) cross-sections and the thermally pulsed s-process model of AGB stars. The observed Eu isotopic composition of SiC grains place constraints on s-process conditions such as the temperature and neutron densities in AGB stars.