The investigator's high pressure studies are oriented towards constraining the behavior of volatiles (particularly water, hydrogen, carbon and nitrogen) within planet Earth. The objectives are to derive constraints on: (1) the volatile content of Earth's core, as evaluated from the high pressure behavior of volatile-bearing iron alloys; (2) how hydrogen and carbon are bound into crystalline assemblages at mantle conditions; and (3) the structure and properties of volatile-rich magmas at high pressures. The methods employed in this work combine vibrational spectroscopy (infrared and Raman spectroscopies) and x-ray diffraction as probes of samples held within the diamond anvil cell, which generate ultra-high pressures. Heating at high pressures is accomplished with either external heaters or laser-heating of samples. The intellectual merits of the proposed experiments include producing fundamental insights into the carbon and hydrogen budgets of planet Earth; evaluating the means by which atmospheric and hydrospheric constituents are degassed from the Earth's interior and then reintroduced into the planet through subduction; and the phase relations and properties of Earth's iron-rich core. The broader impacts of this study includes developing a better understanding of the genesis of Earth's oceans and atmosphere, as well as developing a framework for assessing how two of the most cosmochemically abundant elements, hydrogen and carbon, behave under the extreme conditions of planetary interiors.
