Generation and Expansion of the Impact Plasma Cloud after Dust Impacts on Solar Orbiter

Abstract

Dust grain impacting the spacecraft body can be either partly or totally evaporated and ionized as well as a small part of spacecraft material. A cloud of charged particles (impact cloud) generated by such impact can consequently influence the spacecraft potential and/or measurements of on-board scientific instruments. Electric field antennas are sensitive to these disturbances and typically register signals generated by dust impacts as short transient pulses. This method is commonly used for the detection of dust grains even without dedicated dust detectors. Expanding impact clouds can also influence measurements of other scientific instruments such as magnetometers and particle detectors.The presented study is focused on the understanding of the generation and consequent expansion of impact cloud after dust impacts on Solar Orbiter. The Time Domain Sampler (TDS), a subsystem of the Radio and Plasma Wave (RPW) instrument, is used for the detection of individual dust impacts. Three channels of short electric field waveforms (typically 62.5 ms) provide us with information about the influence of expanding particles on three electric antennas. We have analyzed more than 2000 waveform snapshots with dust impacts in various operation modes (monopole and dipole antenna configurations) of RPW/TDS. Additional information about particles generated by dust impact is provided by the Electron Analyser System (EAS), one of the Solar Wind Analyser (SWA) suite instrument.