Nan Liu is a graduate student at the University of Chicago. Measuring isotopic compositions of individual presolar grains allows us to study the nucleosynthesis in individual stars at a level of detail unavailable to observations by stellar spectroscopy. I am interested in measuring isotopic composition of rare earth elements in single presolar SiC grains. By studying the isotopic compositions of these elements in single grains, we can give valuable constraints on two main parameters characterizing the physical conditions during the s-process in individual stars, which can only be achieved by presolar grain study. I am planning to measure Nd and Gd in individual presolar SiC grains with CHARISMA (Chicago-Argonne Resonant Ionization Spectrometer for Mass Analysis) at Argonne National Laboratory.
At the Robert A. Pritzker Center I prepare standard and presolar grain mounts in the Cosmochemistry Lab and use the Field Museum's Zeiss NTS EVO 60 secondary electron microscope (SEM) to make maps of the mounts prior to analysis.