Simulating plasma production from hypervelocity impacts
- Stanford University, Aeronautics and Astronautics, 496 Lomita Mall, Stanford, California 94305 (United States)
- NASA Ames Research Center, Bldg. 258, Moffett Field, California 94035 (United States)
Hypervelocity particles, such as meteoroids and space debris, routinely impact spacecraft and are energetic enough to vaporize and ionize themselves and as well as a portion of the target material. The resulting plasma rapidly expands into the surrounding vacuum. While plasma measurements from hypervelocity impacts have been made using ground-based technologies such as light gas guns and Van de Graaff dust accelerators, some of the basic plasma properties vary significantly between experiments. There have been both ground-based and in-situ measurements of radio frequency (RF) emission from hypervelocity impacts, but the physical mechanism responsible and the possible connection to the impact-produced plasma are not well understood. Under certain conditions, the impact-produced plasma can have deleterious effects on spacecraft electronics by providing a new current path, triggering an electrostatic discharge, causing electromagnetic interference, or generating an electromagnetic pulse. Multi-physics simulations of plasma production from hypervelocity impacts are presented. These simulations incorporate elasticity and plasticity of the solid target, phase change and plasma formation, and non-ideal plasma physics due to the high density and low temperature of the plasma. A smoothed particle hydrodynamics method is used to perform a continuum dynamics simulation with these additional physics. By examining a series of hypervelocity impacts, basic properties of the impact produced plasma plume (density, temperature, expansion speed, charge state) are determined for impactor speeds between 10 and 72 km/s. For a large range of higher impact speeds (30–72 km/s), we find the temperature is unvarying at 2.5 eV. We also find that the plasma plume is weakly ionized for impact speeds less than 14 km/s and fully ionized for impact speeds greater than 20 km/s, independent of impactor mass. This is the same velocity threshold for the detection of RF emission in recent Van de Graaff experiments, suggesting that the RF is correlated to the formation of fully ionized plasma.
- OSTI ID:
- 22493778
- Journal Information:
- Physics of Plasmas, Vol. 22, Issue 9; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 1070-664X
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
CHARGE STATES
ELASTICITY
ELECTRIC DISCHARGES
ELECTROMAGNETIC PULSES
ELECTRONIC EQUIPMENT
HYDRODYNAMICS
INTERFERENCE
METEOROIDS
PLASMA DENSITY
PLASMA PRODUCTION
PLASMA SIMULATION
PLASTICITY
PLUMES
RADIOWAVE RADIATION
SOLIDS
SPACE VEHICLES
TARGETS
TEMPERATURE RANGE 0065-0273 K
VAN DE GRAAFF ACCELERATORS
VELOCITY