Dust detection by antenna instruments - full 3D modeling of antenna waveforms from first principles

The possibility of detecting dust impacts using the body of a spacecraft as a detector has been known since the Voyager era. The impact of a dust particle on the surface of ot the spacecraft generates the transient impact plasma cloud. The combination of the re-collected charge by the spacecraft and the induced charging from the escaping charges from the impact plasma are responsible for the characteristic shape of the waveforms detected by the antennas. A model has been developed recently that allowed reconstructing the waveforms from first principles, when considering the geometry effects of the expanding plasma cloud with respect to the antennas. Industry standard numerical tools are employed for calculating the magnitude of the induced charge for the full 3D vicinity of the spacecraft. The existing numerical model has been extended by including the physical parameters of the expanding plasma cloud in terms of the velocity distribution of the ions, and the geometrical properties of the expansion. By fitting the measured impact waveforms to the model, the impact location and the parameters of the impact plasma can be determined. This presentation will report on the latest progress made in comparing the full 3D theoretical model with measurements made at the dust accelerator facility operated at the University of Colorado.