Modeling NASA's Deep Impact Mission with Smoothed Particle Hydrodynamics. SAM SKILLMAN (Harvey Mudd College Claremont, CA 91711) FRANCIS X. TIMMES (Los Alamos National Laboratory, Los Alamos, NM, 87545)

NASA's Deep Impact Mission sent a 364 kg impactor into the path of the comet Tempel 1 with a relative velocity of 10.2 km/s on July 4th, 2005. The mission objective was to determine the physical properties of the comet's nucleus in order to further our theories of the formation of the solar system. This research was focused on modeling the impact using a Smoothed Particle Hydrodynamics(SPH) code written by M.S. Warren. An ideal gas equation of state is used with an adiabatic index of 1.3. The density of the comet is assumed to be constant to the depths that the impactor will reach and ranges between 100-900kg/m³ for each individual run. The impact angle was varied until NASA released the known angle of 25 degrees relative to the surface. With the density of the comet set at 500kg/m³, our model suggests that the crater will have a diameter of 80 meters and a depth of 43 meters. Further improvement to this simulation would require a more robust equation of state which is outside the realm of this research.

Visible Light Tomography on FRX-L. ADAM LIGHT (Case Western Reserve University Cleveland, OH 44106) THOMAS INTRATOR (Los Alamos National Laboratory, Los Alamos, NM, 87545)

An optical tomographic system has been developed to analyze plasma structure in the Field Reversed eXperiment - Liner (FRX-L) device at Los Alamos National Laboratory. FRX-L is designed to produce a high-density field-reversed configuration plasma (FRC) for fusion energy research. Visible light emitted by the plasma provides much information about its internal structure and is measured by several diagnostics, including the tomographic system described in this work. The diagnostic system consists of two optical array holders each equipped with eight 200-µm optical fibers arranged in a fan-like geometry. Line-integrated optical brightness data from the fan arrays are converted to a two-dimensional brightness map by tomographic inversion. The system has been calibrated and tested using the known brightness profile of a fluorescent lamp. Inversion routines based on the expansion-in-base-functions method have been developed and preliminary results match the expected hollow density profile of the FRC.