loading page

Variability of Antenna Signals from Dust Impacts
  • Mitchell M. Shen,
  • Zoltan Sternovsky,
  • David M. Malaspina
Mitchell M. Shen
Princeton University

Corresponding Author:[email protected]

Author Profile
Zoltan Sternovsky
University of Colorado Boulder
Author Profile
David M. Malaspina
University of Colorado Boulder
Author Profile


Antenna instrument carried by spacecraft is complementary to dedicated dust detectors by registering transient voltage perturbations caused by impact-generated plasma. The signal waveform contains information about the interaction between the impact-generated plasma cloud and the elements of spacecraft – antenna system. Variability of antenna signals from dust impacts has not yet been systematically characterized. A set of laboratory measurements are performed to characterize signal variations in response to spacecraft parameters (bias voltage and antenna configuration) and impactor parameters (impact speed and composition). These measurements demonstrate that dipole antenna configurations are sensitive to impact location because of how the asymmetric expansion of impact plasma cloud produces different signals among antennas. This result revises previous conclusions that dipole antenna configurations should be insensitive to impacts. When dust impacts occur at low speeds, antenna instruments typically register smaller amplitudes and less characteristic impact signal shapes. In this case, impact event identification becomes challenged by low signal-to-noise ratios and complex waveforms, indicating the compound nature of non-fully developed impact-generated plasmas. Laboratory studies of aluminum dust particle hypervelocity impacts were used to explore the dependence of impact waveform variability on dust composition. No significant variations were determined compared to common iron dust measurements, consistent with prior studies. Additionally, electrostatic model fitting is used to obtain impact plasma parameters from antenna-detected waveform signals. The recovered parameters are comparable to those from Fe dust. This suggests a similarity of fully developed impact plasma cloud behaviors upon hypervelocity impact.