9510333 Daniels This program is directed toward measurement of electronic excited state energies and conduction band gaps in compressed cryocrystals such as solid argon and solid hydrogen using nonlinear optical spectroscopy. These measurements are relevant to deep planetary atmospheres problems and to ongoing questions related to a possible insulator-metal transition in highly compressed hydrogen. The nonlinear optics methods used are required to excite the deep ultraviolet states involved, while probing with optical beams transmittable by pressure cell windows. %%% Properties of crystals such as solid hydrogen and solid argon are crucial to understanding of phenomena in systems as diverse as the deep atmosphere of the planet Jupiter or the change of materials from electrically insulating to conducting when compressed to extremely high pressures. Fundamental to this understanding is a knowledge of how electrons behave at very pressures. This program is applying innovative methods using high-powered laser light pulses to measure electron energies in compressed simple systems including solid hydrogen and argon. ***
