Ice Target and Gas Target Experiments in the IMPACT Dust Accelerator

Monday, 15 December 2014
Tobin L Munsat1, Andrew Collette1, Richard Dee1, Eberhard Gruen2, Mihaly Horanyi3, David James2, Diego Janches4, Sascha Kempf3, John M C Plane5, Anthony J Shu3, Jonas Simolka1, Zoltan Sternovsky1 and Evan Thomas1, (1)University of Colorado, Boulder, CO, United States, (2)Laboratory for Atmospheric and Space Physics, Boulder, CO, United States, (3)University of Colorado at Boulder, Physics, Boulder, CO, United States, (4)NASA/GSFC, Greenbelt, MD, United States, (5)University of Leeds, University of Leeds, Leeds, LS2, United Kingdom
The dust accelerator facility at the SSERVI Institute for Modeling Plasma, Atmospheres, and Cosmic Dust (IMPACT) is presently implementing two major target upgrades: a cryogenic ice target and a high-pressure gas target. The ice target consists of a LN2 cryogenic system connected to both a water-ice deposition system as well as a movable freezer/holder for a pre-mixed liquid cartridge. Planned experiments include the bombardment of a variety of frozen targets and simulated ice/regolith mixtures, and the assessment of all impact products (solid ejecta, gas, plasma) as well as spectroscopy of both the impact-produced light flashes and the reflected spectra (UV, visible, IR). Such measurements are highly relevant to both physical and chemical surface modification of airless bodies due to micrometeoroid impacts. The gas target consists of a differentially pumped chamber kept at moderate background pressures, such that high-velocity (~10 km/s) micrometeoroids are completely ablated within 10's of cm (i.e. within the measurement chamber). The chamber is configured with segmented electrodes to perform a spatially-resolved measurement of charge production during ablation, and localized light-collection optics enable an assessment of the light production (luminous efficiency). Such studies are critical to the understanding of past and future ground-based measurements of meteor ablation in Earth's atmosphere, which in turn can potentially provide the best estimates of the interplanetary dust particle flux.