9813447 Walker The goal of this research is to gain an understanding of planetary differentiation by igneous processes. Methods of study include: (1) melting, element partitioning, and /or decomposition studies of planetary materials and related synthethic compositions using experimental petrology; (2) petrographic and microprobe studies of experimental products and natural samples as well as theoretical and numerical modeling of magmatic systems; (3) technique development for studies of high temperature and pressure phase equilibria, element partitioning and materials behavior. The following projects will be undertaken: (a) exploration of the P, T, and liquid compositional dependence of the partitioning of very highly siderophile elements between melt and silicate liquids; (b) study of the volume of the garnet solution series at simultaneously high P and T by synchrotron XRD; (c) determination of high P, T, volumes of selected fluid substances by tracking relevant crystal decomposition curves using sychrotron XRD; (d) improvement of the doping properties, reliability, and X-ray transparency of semiconductor heaters based on Al carbide and nitride composites; (e) completion of the data reduction of epithermal neutron resonance pyrometry measurements of the effect of P on thermocouple emf.
