HR: 09:45h
AN: V41B-08    [PDF]
TI: Vibrational Spectra of Hot Dense Molecular Fluids: Tabletop Apparatus for Probing Planetary Interiors
AU: * Baer, B J
EM: baer4@llnl.gov
AF: Lawrence Livermore National Laboratory, 7000 East Ave M/S L-41, Livermore, CA 94550 United States
AU: Yoo, C
EM: yoo1@llnl.gov
AF: Lawrence Livermore National Laboratory, 7000 East Ave M/S L-41, Livermore, CA 94550 United States
AB: Spectroscopic information on simple molecules at high temperatures and pressures are necessary for understanding the interiors of the Jovian planets. These conditions easily exceed 2000K and 10 GPa. We shall demonstrate that it is possible to exceed those conditions (statically) and obtain spectroscopic information on such hot dense fluids. This experimental method requires the use of non-linear spectroscopy and CW laser heating on samples that are under pressure inside a diamond-anvil cell. Spectra are obtained by using a four wave mixing technique: Coherent Anti-Stokes Raman Spectroscopy. The sample heating is accomplished by using an in-situ microscopic tungsten toroid as a laser target. By combining these techniques simultaneously, vibrational spectra with relatively high signal to noise can be obtained despite the enormous thermal background generated by the incandescence of extremely hot laser heated material. Temperatures can be measured not only by fitting the Planck radiation to a graybody, but by the spectroscopic evidence of a Boltzmann distribution of molecules in their excited vibrational quantum levels. Our initial experiments will describe these technical developments and demonstrate their success using nitrogen samples.
DE: 0350 Pressure, density, and temperature
DE: 3924 High-pressure behavior
DE: 3934 Optical, infrared, and Raman spectroscopy
DE: 5754 Physical properties of materials
DE: 5794 Instruments and techniques
SC: Volcanology, Geochemistry, Petrology [V]
MN: 2003 Fall Meeting